Introduction

Through our daily threat hunting, we noticed that, beginning in July 2025, a series of malicious wheel packages were uploaded to PyPI (the Python Package Index). We shared this information with the public security community, and the malware was removed from the repository. We submitted the samples to Kaspersky Threat Attribution Engine (KTAE) for analysis. Based on the results, we believe the packages may be linked to malware discussed in a Threat Intelligence report on OceanLotus.

While these wheel packages do implement the features described on their PyPI web pages, their true purpose is to covertly deliver malicious files. These files can be either .DLL or .SO (Linux shared library), indicating the packages’ ability to target both Windows and Linux platforms. They function as droppers, delivering the final payload – a previously unknown malware family that we have named ZiChatBot. Unlike traditional malware, ZiChatBot does not communicate with a dedicated command and control (C2) server, but instead uses a series of REST APIs from the public team chat app Zulip as its C2 infrastructure.

To conceal the malicious package containing ZiChatBot, the attacker created another benign-looking package that included the malicious package as a dependency. Based on these facts, we confirm that this campaign is a carefully planned and executed PyPI supply chain attack.

Technical details

Spreading

The attacker created three projects on PyPI and uploaded malicious wheel packages designed to imitate popular libraries, tricking users into downloading them. This is a clear example of a supply chain attack via PyPI. See below for detailed information about the fake libraries and their corresponding wheel packages.

Malicious wheel packages

The packages added by the attacker and listed on PyPI’s download pages are:

• uuid32-utils library for generating a 32-character random string as a UUID
• colorinal library for implementing cross-platform color terminal text
• termncolor library for ANSI color format for terminal output

The key metadata for these packages are as follows:

Based on the distribution information on the PyPI web page, we can see that it offers X86 and X64 versions for Windows, as well as an x86_64 version for Linux. The colorinal project, for example, provides the following download options:

Distribution information of the colorinal project

Initial infection

The uuid32-utils and colorinal libraries employ similar infection chains and malicious payloads. As a result, this analysis will focus on the colorinal library as a representative example.

A quick look at the code of the third library, termncolor, reveals no apparent malicious content. However, it imports the malicious colorinal library as a dependency. This method allows attackers to deeply conceal malware, making the termncolor library appear harmless when distributing it or luring targets.

The termncolor library imports the malicious colorinal library

During the initial infection stage, the Python code is nearly identical across both Windows and Linux platforms. Here, we analyze the Windows version as an example.

Windows version

Once a Python user downloads and installs the colorinal-0.1.7-py3-none-win_amd64.whl wheel package file, or installs it using the pip tool, the ZiChatBot’s dropper (a file named terminate.dll) will be extracted from the wheel package and placed on the victim’s hard drive.

After that, if the colorinal library is imported into the victim’s project, the Python script file at [Python library installation path]\colorinal-0.1.7-py3-none-win_amd64\colorinal\__init__.py will be executed first.

The __init__.py script imports the malicious file unicode.py

This Python script imports and executes another script located at [python library install path]\colorinal-0.1.7-py3-none-win_amd64\colorinal\unicode.py. The is_color_supported() function in unicode.py is called immediately.

The code loads the dropper into the host Python process

The comment in the is_color_supported() function states that the highlighted code checks whether the user’s terminal environment supports color. The code actually loads the terminate.dll file into the Python process and then invokes the DLL’s exported function envir, passing the UTF-8-encoded string xterminalunicod as a parameter. The DLL acts as a dropper, delivering the final payload, ZiChatBot, and then self-deleting. At the end of the is_color_supported() function, the unicode.py script file is also removed. These steps eliminate all malicious files in the library and deploy ZiChatBot.
For the Linux platform, the wheel package and the unicode.py Python script are nearly identical to the Windows version. The only difference is that the dropper file is named “terminate.so”.

Dropper for ZiChatBot

From the previous analysis, we learned that the dropper is loaded into the host Python process by a Python script and then activated. The main logic of the dropper is implemented in the envir export function to achieve three objectives:

1. Deploy ZiChatBot.
2. Establish an auto-run mechanism.
3. Execute shellcode to remove the dropper file (terminate.dll) and the malicious script file from the installed library folder.

The dropper first decrypts sensitive strings using AES in CBC mode. The key is the string-type parameter “xterminalunicode” of the exported function. The decrypted strings are “libcef.dll”, “vcpacket”, “pkt-update”, and “vcpktsvr.exe”.

Next, the malware uses the same algorithm to decrypt the embedded data related to ZiChatBot. It then decompresses the decrypted data with LZMA to retrieve the files vcpktsvr.exe and libcef.dll associated with ZiChatBot. The malware creates a folder named vcpacket in the system directory %LOCALAPPDATA%, and places these files into it.

To establish persistence for ZiChatBot, the dropper creates the following auto-run entry in the registry:

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run]
"pkt-update"="C:\Users\[User name]\AppData\Local\vcpacket\vcpktsvr.exe"

Once preparations are complete, the malware uses the XOR algorithm to decrypt the embedded shellcode with the three-byte key 3a7. It then searches the decrypted shellcode’s memory for the string Policy.dllcppage.dll and replaces it with its own file name, terminate.dll, and redirects execution to the shellcode’s memory space.

The shellcode employs a djb2-like hash method to calculate the names of certain APIs and locate their addresses. Using these APIs, it finds the dropper file with the name terminate.dll that was previously passed by the DLL before unloading and deleting it.

Linux version

The Linux version of the dropper places ZiChatBot in the path /tmp/obsHub/obs-check-update and then creates an auto-run job using crontab. Unlike the Windows version, the Linux version of ZiChatBot only consists of one ELF executable file.

system("chmod +x /tmp/obsHub/obs-check-update") 
system("echo \"5 * * * * /tmp/obsHub/obs-check-update" | crontab - ")

ZiChatBot

The Windows version of ZiChatBot is a DLL file (libcef.dll) that is loaded by the legitimate executable vcpktsvr.exe (hash: 48be833b0b0ca1ad3cf99c66dc89c3f4). The DLL contains several export functions, with the malicious code implemented in the cef_api_mash export. Once the DLL is loaded, this function is invoked by the EXE file. ZiChatBot uses the REST APIs from Zulip, a public team chat application, as its command and control server.

ZiChatBot is capable of executing shellcode received from the server and only supports this one control command. Once it runs, it initiates a series of sequential HTTP requests to the Zulip REST API.

In each HTTP request, an API authentication token is included as an HTTP header for server-side authentication, as shown below.

// Auth token:
TW9yaWFuLWJvdEBoZWxwZXIuenVsaXBjaGF0LmNvbTpVOFJFWGxJNktmOHFYQjlyUXpPUEJpSUE0YnJKNThxRw==

// Decoded Auth token
Morian-bot@helper.zulipchat.com:U8REXlI6Kf8qXB9rQzOPBiIA4brJ58qG

ZiChatBot utilizes two separate channel-topic pairs for its operations. One pair transmits current system information, and the other retrieves a message containing shellcode. Once the shellcode is received, a new thread is created to execute it. After executing the command, a heart emoji is sent in response to the original message to indicate the execution was successful.

Infrastructure

We did not find any traditional infrastructure, such as compromised servers or commercial VPS services and their associated IPs and domains. Instead, the malicious wheel packages were uploaded to the Python Package Index (PyPI), a public, shared Python library. The malware, ZiChatBot, leverages Zulip’s public team chat REST APIs as its command and control server.

The “helper” organization that the attacker had registered on the Zulip service has now been officially deactivated by Zulip. However, infected devices may still attempt to connect to the service, so to help you locate and cure them, we recommend adding the full URL helper.zulipchat.com to your denylist.

Victims

The malware was uploaded in July 2025. Upon discovering these attacks, we quickly released an update for our product to detect the relevant files and shared the necessary information with the public security community. As a result, the malicious software was swiftly removed from PyPI, and the organization registered on the Zulip service was officially deactivated. To date, we have not observed any infections based on our telemetry or public reports.

Zulip has officially deactivated the “helper” organization

Attribution

Based on the results from our KTAE system, the dropper used by ZiChatBot shows a 64% similarity to another dropper we analyzed in a TI report, which was linked to OceanLotus. Reverse engineering shows that both droppers use nearly identical algorithms and logic for to decrypt and decompress their embedded payloads.

Analysis results of dropper using KTAE system

Conclusions

As an active APT organization, OceanLotus primarily targets victims in the Asia-Pacific region. However, our previous reports have highlighted a growing trend of the group expanding its activities into the Middle East. Moreover, the attacks described in this report – executed through PyPI – target Python users worldwide. This demonstrates OceanLotus’s ongoing effort to broaden its attack scope.

In the first half of 2025, a public report revealed that the group launched a phishing campaign using GitHub. The recent PyPI-based supply chain attack likely continues this strategy. Although phishing emails are still a common initial infection method for OceanLotus, the group is also actively exploring new ways to compromise victims through diverse supply chain attacks.

Indicators of compromise

Additional information about this activity, including indicators of compromise, is available to customers of the Kaspersky Intelligence Reporting Service. If you are interested, please contact intelreports@kaspersky.com.

Malicious wheel packages
termncolor-3.1.0-py3-none-any.whl
5152410aeef667ffaf42d40746af4d84

uuid32_utils-1.x.x-py3-none-xxxx.whl
0a5a06fa2e74a57fd5ed8e85f04a483a
e4a0ad38fd18a0e11199d1c52751908b
5598baa59c716590d8841c6312d8349e
968782b4feb4236858e3253f77ecf4b0
b55b6e364be44f27e3fecdce5ad69eca
02f4701559fc40067e69bb426776a54f
e200f2f6a2120286f9056743bc94a49d
22538214a3c917ff3b13a9e2035ca521

colorinal-0.1.7-py3-none-xxxx.whl
ba2f1868f2af9e191ebf47a5fab5cbab

Dropper for ZiChatBot
Backward.dll
c33782c94c29dd268a42cbe03542bca5
454b85dc32dc8023cd2be04e4501f16a

Backward.so
fce65c540d8186d9506e2f84c38a57c4
652f4da6c467838957de19eed40d39da

terminate.dll
1995682d600e329b7833003a01609252

terminate.so
38b75af6cbdb60127decd59140d10640

ZiChatBot
libcef.dll
a26019b68ef060e593b8651262cbd0f6

Introduction

Through our daily threat hunting, we noticed that, beginning in July 2025, a series of malicious wheel packages were uploaded to PyPI (the Python Package Index). We shared this information with the public security community, and the malware was removed from the repository. We submitted the samples to Kaspersky Threat Attribution Engine (KTAE) for analysis. Based on the results, we believe the packages may be linked to malware discussed in a Threat Intelligence report on OceanLotus.

While these wheel packages do implement the features described on their PyPI web pages, their true purpose is to covertly deliver malicious files. These files can be either .DLL or .SO (Linux shared library), indicating the packages’ ability to target both Windows and Linux platforms. They function as droppers, delivering the final payload – a previously unknown malware family that we have named ZiChatBot. Unlike traditional malware, ZiChatBot does not communicate with a dedicated command and control (C2) server, but instead uses a series of REST APIs from the public team chat app Zulip as its C2 infrastructure.

To conceal the malicious package containing ZiChatBot, the attacker created another benign-looking package that included the malicious package as a dependency. Based on these facts, we confirm that this campaign is a carefully planned and executed PyPI supply chain attack.

Technical details

Spreading

The attacker created three projects on PyPI and uploaded malicious wheel packages designed to imitate popular libraries, tricking users into downloading them. This is a clear example of a supply chain attack via PyPI. See below for detailed information about the fake libraries and their corresponding wheel packages.

Malicious wheel packages

The packages added by the attacker and listed on PyPI’s download pages are:

• uuid32-utils library for generating a 32-character random string as a UUID
• colorinal library for implementing cross-platform color terminal text
• termncolor library for ANSI color format for terminal output

The key metadata for these packages are as follows:

Based on the distribution information on the PyPI web page, we can see that it offers X86 and X64 versions for Windows, as well as an x86_64 version for Linux. The colorinal project, for example, provides the following download options:

Distribution information of the colorinal project

Initial infection

The uuid32-utils and colorinal libraries employ similar infection chains and malicious payloads. As a result, this analysis will focus on the colorinal library as a representative example.

A quick look at the code of the third library, termncolor, reveals no apparent malicious content. However, it imports the malicious colorinal library as a dependency. This method allows attackers to deeply conceal malware, making the termncolor library appear harmless when distributing it or luring targets.

The termncolor library imports the malicious colorinal library

During the initial infection stage, the Python code is nearly identical across both Windows and Linux platforms. Here, we analyze the Windows version as an example.

Windows version

Once a Python user downloads and installs the colorinal-0.1.7-py3-none-win_amd64.whl wheel package file, or installs it using the pip tool, the ZiChatBot’s dropper (a file named terminate.dll) will be extracted from the wheel package and placed on the victim’s hard drive.

After that, if the colorinal library is imported into the victim’s project, the Python script file at [Python library installation path]\colorinal-0.1.7-py3-none-win_amd64\colorinal\__init__.py will be executed first.

The __init__.py script imports the malicious file unicode.py

This Python script imports and executes another script located at [python library install path]\colorinal-0.1.7-py3-none-win_amd64\colorinal\unicode.py. The is_color_supported() function in unicode.py is called immediately.

The code loads the dropper into the host Python process

The comment in the is_color_supported() function states that the highlighted code checks whether the user’s terminal environment supports color. The code actually loads the terminate.dll file into the Python process and then invokes the DLL’s exported function envir, passing the UTF-8-encoded string xterminalunicod as a parameter. The DLL acts as a dropper, delivering the final payload, ZiChatBot, and then self-deleting. At the end of the is_color_supported() function, the unicode.py script file is also removed. These steps eliminate all malicious files in the library and deploy ZiChatBot.
For the Linux platform, the wheel package and the unicode.py Python script are nearly identical to the Windows version. The only difference is that the dropper file is named “terminate.so”.

Dropper for ZiChatBot

From the previous analysis, we learned that the dropper is loaded into the host Python process by a Python script and then activated. The main logic of the dropper is implemented in the envir export function to achieve three objectives:

1. Deploy ZiChatBot.
2. Establish an auto-run mechanism.
3. Execute shellcode to remove the dropper file (terminate.dll) and the malicious script file from the installed library folder.

The dropper first decrypts sensitive strings using AES in CBC mode. The key is the string-type parameter “xterminalunicode” of the exported function. The decrypted strings are “libcef.dll”, “vcpacket”, “pkt-update”, and “vcpktsvr.exe”.

Next, the malware uses the same algorithm to decrypt the embedded data related to ZiChatBot. It then decompresses the decrypted data with LZMA to retrieve the files vcpktsvr.exe and libcef.dll associated with ZiChatBot. The malware creates a folder named vcpacket in the system directory %LOCALAPPDATA%, and places these files into it.

To establish persistence for ZiChatBot, the dropper creates the following auto-run entry in the registry:

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run]
"pkt-update"="C:\Users\[User name]\AppData\Local\vcpacket\vcpktsvr.exe"

Once preparations are complete, the malware uses the XOR algorithm to decrypt the embedded shellcode with the three-byte key 3a7. It then searches the decrypted shellcode’s memory for the string Policy.dllcppage.dll and replaces it with its own file name, terminate.dll, and redirects execution to the shellcode’s memory space.

The shellcode employs a djb2-like hash method to calculate the names of certain APIs and locate their addresses. Using these APIs, it finds the dropper file with the name terminate.dll that was previously passed by the DLL before unloading and deleting it.

Linux version

The Linux version of the dropper places ZiChatBot in the path /tmp/obsHub/obs-check-update and then creates an auto-run job using crontab. Unlike the Windows version, the Linux version of ZiChatBot only consists of one ELF executable file.

system("chmod +x /tmp/obsHub/obs-check-update") 
system("echo \"5 * * * * /tmp/obsHub/obs-check-update" | crontab - ")

ZiChatBot

The Windows version of ZiChatBot is a DLL file (libcef.dll) that is loaded by the legitimate executable vcpktsvr.exe (hash: 48be833b0b0ca1ad3cf99c66dc89c3f4). The DLL contains several export functions, with the malicious code implemented in the cef_api_mash export. Once the DLL is loaded, this function is invoked by the EXE file. ZiChatBot uses the REST APIs from Zulip, a public team chat application, as its command and control server.

ZiChatBot is capable of executing shellcode received from the server and only supports this one control command. Once it runs, it initiates a series of sequential HTTP requests to the Zulip REST API.

In each HTTP request, an API authentication token is included as an HTTP header for server-side authentication, as shown below.

// Auth token:
TW9yaWFuLWJvdEBoZWxwZXIuenVsaXBjaGF0LmNvbTpVOFJFWGxJNktmOHFYQjlyUXpPUEJpSUE0YnJKNThxRw==

// Decoded Auth token
Morian-bot@helper.zulipchat.com:U8REXlI6Kf8qXB9rQzOPBiIA4brJ58qG

ZiChatBot utilizes two separate channel-topic pairs for its operations. One pair transmits current system information, and the other retrieves a message containing shellcode. Once the shellcode is received, a new thread is created to execute it. After executing the command, a heart emoji is sent in response to the original message to indicate the execution was successful.

Infrastructure

We did not find any traditional infrastructure, such as compromised servers or commercial VPS services and their associated IPs and domains. Instead, the malicious wheel packages were uploaded to the Python Package Index (PyPI), a public, shared Python library. The malware, ZiChatBot, leverages Zulip’s public team chat REST APIs as its command and control server.

The “helper” organization that the attacker had registered on the Zulip service has now been officially deactivated by Zulip. However, infected devices may still attempt to connect to the service, so to help you locate and cure them, we recommend adding the full URL helper.zulipchat.com to your denylist.

Victims

The malware was uploaded in July 2025. Upon discovering these attacks, we quickly released an update for our product to detect the relevant files and shared the necessary information with the public security community. As a result, the malicious software was swiftly removed from PyPI, and the organization registered on the Zulip service was officially deactivated. To date, we have not observed any infections based on our telemetry or public reports.

Zulip has officially deactivated the “helper” organization

Attribution

Based on the results from our KTAE system, the dropper used by ZiChatBot shows a 64% similarity to another dropper we analyzed in a TI report, which was linked to OceanLotus. Reverse engineering shows that both droppers use nearly identical algorithms and logic for to decrypt and decompress their embedded payloads.

Analysis results of dropper using KTAE system

Conclusions

As an active APT organization, OceanLotus primarily targets victims in the Asia-Pacific region. However, our previous reports have highlighted a growing trend of the group expanding its activities into the Middle East. Moreover, the attacks described in this report – executed through PyPI – target Python users worldwide. This demonstrates OceanLotus’s ongoing effort to broaden its attack scope.

In the first half of 2025, a public report revealed that the group launched a phishing campaign using GitHub. The recent PyPI-based supply chain attack likely continues this strategy. Although phishing emails are still a common initial infection method for OceanLotus, the group is also actively exploring new ways to compromise victims through diverse supply chain attacks.

Indicators of compromise

Additional information about this activity, including indicators of compromise, is available to customers of the Kaspersky Intelligence Reporting Service. If you are interested, please contact intelreports@kaspersky.com.

Malicious wheel packages
termncolor-3.1.0-py3-none-any.whl
5152410aeef667ffaf42d40746af4d84

uuid32_utils-1.x.x-py3-none-xxxx.whl
0a5a06fa2e74a57fd5ed8e85f04a483a
e4a0ad38fd18a0e11199d1c52751908b
5598baa59c716590d8841c6312d8349e
968782b4feb4236858e3253f77ecf4b0
b55b6e364be44f27e3fecdce5ad69eca
02f4701559fc40067e69bb426776a54f
e200f2f6a2120286f9056743bc94a49d
22538214a3c917ff3b13a9e2035ca521

colorinal-0.1.7-py3-none-xxxx.whl
ba2f1868f2af9e191ebf47a5fab5cbab

Dropper for ZiChatBot
Backward.dll
c33782c94c29dd268a42cbe03542bca5
454b85dc32dc8023cd2be04e4501f16a

Backward.so
fce65c540d8186d9506e2f84c38a57c4
652f4da6c467838957de19eed40d39da

terminate.dll
1995682d600e329b7833003a01609252

terminate.so
38b75af6cbdb60127decd59140d10640

ZiChatBot
libcef.dll
a26019b68ef060e593b8651262cbd0f6

As Frontier AI crosses new thresholds, the landscape for both attackers and defenders is shifting. At Palo Alto Networks, we are committed to ensuring defenders maintain the advantage.

To deliver this critical edge, our Unit 42 Frontier AI Defense will now leverage Anthropic’s Claude Security, powered by Opus 4.7. By integrating one of the world’s most advanced AI models, we are empowering our customers to outpace automated threats. Through Frontier AI Defense, organizations can rapidly assess their security posture, remediate vulnerabilities and harden their infrastructure against next-generation, AI-driven attacks.

We are utilizing Claude Security’s deep technical reasoning to enable our customers to find and fix vulnerabilities with unprecedented speed. This includes:

1. AI-Driven Exposure Analysis – Identifying complex exploit chains that turn minor findings into critical risks.
2. Scalable Application Analysis – Performing deep-stack code reviews at a scale and depth previously unavailable.
3. Agentic Defense – Powering autonomous workflows that detect and remediate threats at machine speed, backed by human oversight.

Palo Alto Networks is also participating in Anthropic's Cyber Verification Program, which credentials security teams for legitimate defensive use of frontier models.

The threat timeline is accelerating. Within months, AI-driven attack capabilities will become a standard fixture of the threat landscape. Palo Alto Networks is dedicated to ensuring our global customers are equipped with the modern frontier AI models necessary to stay secure both today and tomorrow.

The post Enhancing AI-Driven Defense with Anthropic’s Claude Opus 4.7 appeared first on Palo Alto Networks Blog.

Authors: Yun Zheng Hu and Mick Koomen

Introduction

In the past few years, Fox-IT and NCC Group have conducted multiple incident response cases involving a Lazarus subgroup that specifically targets organizations in the financial and cryptocurrency sector. This Lazarus subgroup overlaps with activity linked to AppleJeus¹, Citrine Sleet², UNC4736³, and Gleaming Pisces⁴. This actor uses different remote access trojans (RATs) in their operations, known as PondRAT⁵, ThemeForestRAT and RemotePE. In this article, we analyse and discuss these three.

First, we describe an incident response case from 2024, where we observed the three RATs. This gives insights into the tactics, techniques, and procedures (TTPs) of this actor. Then, we discuss PondRAT, ThemeForestRAT and RemotePE, respectively.

PondRAT received quite some attention last year, we give a brief overview of the malware and document other similarities between PondRAT and POOLRAT (also known as SimpleTea) that have not yet been publicly documented. Secondly, we discuss ThemeForestRAT, a RAT that has been in use for at least six years now, but has not yet been discussed publicly. These two malware families were used in conjunction, where PondRAT was on disk and ThemeForestRAT seemed to only run in memory.

Lastly, we briefly describe RemotePE, a more advanced RAT of this group. We found evidence that the actor cleaned up PondRAT and ThemeForestRAT artifacts and subsequently installed RemotePE, potentially signifying a next stage in the attack. We cannot directly link RemotePE to any public malware family at the time of this writing.

In all cases, the actor used social engineering as an initial access vector. In one case, we suspect a zero-day might have been used to achieve code execution on one of the victim’s machines. We think this highlights their advanced capabilities, and with their history of activity, also shows their determination.

A Telegram from Pyongyang

In 2024, Fox-IT investigated an incident at an organisation in decentralized finance (DeFi). There, an employee’s machine was compromised through social engineering. From there, the actor performed discovery from inside the network using different RATs in combination with other tools, for example, to harvest credentials or proxy connections. Afterwards, the actor moved to a stealthier RAT, likely signifying a next stage in the attack.

In Figure 1, we provide an overview of the attack chain, where we highlight four phases of the attack:

1. Social engineering: the actor impersonates an existing employee of a trading company on Telegram and sets up a meeting with the victim, using fake meeting websites.
2. Exploitation: the victim machine gets compromised and shortly afterwards PondRAT is deployed. We are uncertain how the compromise was achieved, though we suspect a Chrome zero-day vulnerability was used.
3. Discovery: the actor uses various tooling to explore the victim network and observe daily activities.
4. Next phase: after three months, the actor removes PerfhLoader, PondRAT and ThemeForestRAT and deploys a more advanced RAT, which we named RemotePE.

Social Engineering

We found traces matching a social engineering technique previously described by SlowMist⁶. This social engineering campaign targets employees of companies active in the cryptocurrency sector by posing as employees of investment institutions on Telegram.

This Lazarus subgroup uses fake Calendly and Picktime websites, including fake websites of the organisations they impersonate. We found traces of two impersonated employees of two different companies. We did not observe any domains linked to the “Access Restricted” trick as described by SlowMist. In Figure 2, you can see a Telegram message from the actor, impersonating an existing employee of a trading company. Looking up the impersonated person, showed that the person indeed worked at the trading company.

From the forensic data, we could not establish a clear initial access vector. We suspect a Chrome zero-day exploit was used. Although, we have no actual forensic data to back up this claim, we did notice changes in endpoint logging behaviour. Around the time of compromise, we noted a sudden decrease in the logging of the endpoint detection agent that was running on the machine. Later, Microsoft published a blogpost⁷, describing Citrine Sleet using a zero-day Chrome exploit to launch an evasive rootkit called FudModule⁸, which could explain this behaviour.

Persistence with PerfhLoader

The actor leveraged the SessionEnv service for persistence. This existing Windows service is vulnerable to phantom DLL loading⁹. A custom TSVIPSrv.dll can be placed inside the %SystemRoot%\System32\ directory, which SessionEnv will load upon startup. The actor placed its own loader in this directory, which we refer to as PerfhLoader. Persistence was ensured by making the service start automatically at reboot using the following command:

sc config sessionenv start=auto

The actor also modified the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SessionEnv\RequiredPrivileges registry key by adding SeDebugPrivilege and SeLoadDriverPrivilege privileges. These elevated privileges enable loading kernel drivers, which can bypass or disable Endpoint Detection and Response (EDR) tools on the compromised system.

In a case from 2020¹⁰, this actor used the IKEEXT service for phantom DLL loading, writing PerfhLoader to the path %SystemRoot%\System32\wlbsctrl.dll. The vulnerable VIAGLT64.SYS kernel driver (CVE-2017-16237) was also used to gain SYSTEM privileges.

PerfhLoader is a simple loader that reads a file with a hardcoded filename (perfh011.dat) from its current directory, decrypts its contents, loads it into memory and executes it. In all observed cases, both PerfhLoader and the encrypted DLL were in the %SystemRoot%\System32\ folder. Normally, perfhXXX.dat files located in this folder contain Windows Performance Monitor data, which makes it blend in with normal Windows file names.

The cipher used to encrypt and decrypt the payload uses a rolling XOR key, we denote the implementation in Python code in Listing 1.

def crypt_buf(data: bytes) -> bytes:
    xor_key = bytearray(range(0x10))
    buf = bytearray(data)
    for idx in range(len(buf)):
        a = xor_key[(idx + 5) & 0xF]
        b = xor_key[(idx - 3) & 0xF]
        c = xor_key[(idx - 7) & 0xF]
        xor_byte = a ^ b ^ c
        buf[idx] ^= xor_byte
        xor_key[idx & 0xF] = xor_byte
 
    return bytes(buf)

Listing 1: Python implementation of the XOR cipher used by PerfhLoader

The decrypted content contains a DLL that PerfhLoader loads into memory using the Manual-DLL-Loader project¹¹. Interestingly, PondRAT uses this same project for DLL loading.

Discovery

After establishing a foothold, the actor deployed various tools in combination with the RATs described earlier. These included both custom tooling and publicly available tools. Table 1 lists some of the tools we recovered that the actor used.

Interestingly, the Fast Reverse Proxy client we found was the same client found in the 3CX compromise by Mandiant¹⁵. This client is version 0.32.1¹⁶ and is from 2020, which is remarkable. We also found traces of a Themida-packed version of Quasar¹⁷, a malware family we did not see this Lazarus subgroup use before.

The actor used PondRAT in combination with ThemeForestRAT for roughly three months, to afterwards clean up and install the more sophisticated RAT called RemotePE. We will now discuss these three RATs.

PondRAT

PondRAT is a simple RAT, which its authors seem to refer to as “firstloader”, based on the compilation metadata string objc_firstloader that is present in the macOS samples.

In our case, PondRAT was the initial access payload used to deploy other types of malware, including ThemeForestRAT. Judging from network data, apart from ThemeForestRAT activity, we observed significant activity to the PondRAT C2 server, indicating it was not just used for its loader functionality. In the incident response case from 2020 we encountered POOLRAT in combination with ThemeForestRAT. This could indicate that PondRAT is a successor of POOLRAT.

Overview

PondRAT is a straightforward RAT that allows an operator to read and write files, start processes and run shellcode. It has already been described by some vendors. As far as we know, the earliest sample is from 2021, referenced in a CISA article¹⁸. Based on PondRAT’s user-agent, we also noticed that PondRAT was used in an AppleJeus campaign Volexity wrote about¹⁹ (MSI file with hash 435c7b4fd5e1eaafcb5826a7e7c16a83). 360 Threat Intelligence Center wrote about PondRAT as well²⁰, linking it to Lazarus and later writing about it being distributed through Python Package Index (PyPI) packages²¹. Vipyr Security wrote²² about malware that was dropped through malicious Python packages distributed through PyPI, which turned out to be PondRAT. Unit42 published an analysis²³ of the RAT, referring to it as PondRAT and showing similarities between PondRAT and another RAT used by Lazarus: POOLRAT.

As described by Unit42, there are similarities between POOLRAT and PondRAT. There is overlap in function and class naming and both families check for successful responses in a similar way.

POOLRAT has more functionality than PondRAT. For example, POOLRAT has a configuration file for C2 servers, can timestomp²⁴ files, can move files around, functionalities that PondRAT lacks. We think this is because there is no need for more functionality if its main function is to load other malware, allowing for a smaller code base and less maintenance.

Command and Control

PondRAT communicates over HTTP(S) with a hardcoded C2 server. Messages sent between the malware and the server are XOR-ed first and then Base64-encoded. For XORing it uses the hex-encoded key 774C71664D5D25775478607E74555462773E525E18237947355228337F433A3B.

Figure 4 contains an example check-in request to the C2 server. The tuid parameter contains the bot ID, control indicates the request type, and the payload parameter contains the encrypted check-in information. In this case, control is set to fconn, indicating it is a bot check-in, matching with the corresponding function name FConnectProxy(). When receiving a server reply starting with OK, PondRAT fetches a command from the server. For at least one Linux and macOS variant, the parameter names and string values consisted of scrambled letters, e.g. lkjyhnmiop instead of tuid and odlsjdfhw instead of fconn.

Commands

PondRAT has basic commands, such as reading and writing files and executing programs. Table 2 lists all commands and their names from the symbol data. When a bot command is executed, the response includes both the original command ID and a status code indicating either success (0x89A) or failure (0x89B).

Windows

Only the Windows samples we analysed had support for commands 0x896 and 0x89C. The DLL loading functionality seems to be based on the open-source project “Manual-DLL-Loader”²⁵. As a sidenote, we analysed another POOLRAT Windows sample that used the “SimplePELoader” project²⁶.

POOLRAT’s Little Brother

As mentioned by Palo Alto’s Unit42, PondRAT has similarities with POOLRAT. There is overlap in XOR keys, function naming and class naming. However, there are more similarities. Firstly, the Windows versions of PondRAT and POOLRAT use the format string %sd.e%sc "%s > %s 2>&1" for launching a shell command. Format strings have been discussed in the past²⁷ and this specific format string was linked to Operation Blockbuster Sequel. Furthermore, PondRAT has a peculiar way of generating its bot ID, see the decompiled code below.

Figure 5 shows how PondRAT and POOLRAT compute their bot ID. For PondRAT, tuid is the bot ID. It computes two parts of a 32-bit integer, that are split in two based on the bit_shift variable. Some of the POOLRAT samples compute the bot ID in a similar manner. The sample 6f2f61783a4a59449db4ba37211fa331 has symbol information available and contains a function named GenerateSessionId() that has this same logic.

More similarities can be found as part of the C2 protocol. PondRAT provides feedback to commands issued by the C2 server by returning the command ID concatenated with the status code. POOLRAT uses the same concept, see Figure 6.

Another similarity can be found when comparing the Windows versions of POOLRAT and PondRAT. When running a Shell command (command ID 0x898) with PondRAT, the Windows version creates a temporary file with the prefix TLT in which it saves the command output. Then, it reads the file and sends the contents back to the C2 server and subsequently removes it. However, the way it removes the temporary file is remarkable.

It generates a buffer with random bytes and overwrites the file contents with it. Then, it renames the file 27 times, replacing all letters with only A’s, then B’s, etc. and with the last iteration renames all letters with random uppercase letters. For instance, when the file C:\Windows\Temp\tlt1bd8.tmp is deleted, it would first be renamed to C:\Windows\Temp\AAAAAAA.AAA, then to C:\Windows\Temp\BBBBBBB.BBB, and lastly to something like VYLDVAP.XQA. POOLRAT’s Windows version has the same functionality, see Figure 7.

These similarities show that apart from variable data and symbol names, PondRAT is similar to POOLRAT in coding concepts as well. This further strengthens the connection between the two.

Summary

PondRAT is a simple RAT. Judging from the symbol data of macOS samples, its authors seem to refer to the malware as firstloader, a RAT that targets all three major operating systems. In our case, we observed it in combination with social engineering campaigns, whereas others have seen PondRAT being dropped through malicious software packages. Despite being simple in nature, it seems to do the job, given the frequency in which it is used. Judging from past incidents we investigated, PondRAT is a successor of POOLRAT.

Run, ThemeForest, Run!

In two incident response cases we found traces of a different RAT being used in conjunction with POOLRAT or PondRAT. We named it ThemeForestRAT, based on the substring ThemeForest which it uses in its C2 protocol. It is written in C++ and contains class names such as CServer, CJobManager, CSocketEx, CZipper and CUsbMan. ThemeForestRAT has more functionalities compared to PondRAT and POOLRAT.

In an earlier incident response case in 2020, we observed ThemeForestRAT in combination with POOLRAT. In the case from 2024, we observed it together with PondRAT. Its continued activity over at least five years demonstrates that ThemeForestRAT remains a relevant and capable tool for this actor. Besides Windows, we have observed Linux and macOS versions of the malware.

We believe that on Windows, this RAT is injected and executed in memory only, for example via PondRAT, or a dedicated loader, and is used as stealthier second-stage RAT with more functionality. The fact there are no direct samples of ThemeForestRAT on VirusTotal indicates it is quite successful in staying under the radar.

Overview

On startup, ThemeForestRAT attempts to read the configuration file from disk. When absent, it generates a unique bot ID and uses the hardcoded C2 configuration settings in the binary to create the configuration file.

Interestingly, the Windows variant creates two Windows events and accompanying threads that are used for signalling purposes (see Figure 8). However, the first thread related to the class CUsbMan only creates the temporary directory Z802056 and returns, this turned out to be legacy code as we will describe later.

The second thread monitors for new Remote Desktop (RDP) sessions and notifies the main thread when one is detected. Additionally, the thread checks for new physical console sessions and can optionally spawn extra commands under this session if this is enabled in the configuration.

After creating these two threads it hibernates before connecting to the C2 server. The default hibernation period is three minutes but when it runs for the first time it checks in immediately. There are two cases where ThemeForestRAT wakes up from hibernation, either the hibernation period has passed, or one of the two events is signalled.

When it wakes up from hibernation it randomly selects a C2 server from its list and attempts to establish a connection. Upon receiving a response:OK acknowledgment, it downloads a 4-byte file that must decrypt to the 32-bit constant 0x20191127 to establish a valid C2 session. If this fails it will retry a different C2 and start over again, when the list of servers is exhausted it will go back into hibernation and try again later.

If it succeeds in establishing a C2 session, ThemeForestRAT sends basic system information including its wake-up reason to the C2 server, and the operator can now interact with the RAT as it keeps polling for new commands. When the operator sends an OnTerminate or OnSleep command (see Table 4), the C2 session ends, and the RAT goes back to hibernation.

struct SystemInfoWindows   // sizeof=0x478
{
    uint32  job_id;        // 0x10005 = Windows
    wchar   bot_id[20];
    wchar   hostname[64];
    wchar   whoami[50];
    uint32  dwMajorVersion;
    uint32  dwMinorVersion;
    uint32  dwPlatformId;
    uint16  padding1;
    wchar   ip_address[20];
    wchar   timezone[50];
    wchar   gpu[50];
    wchar   memory[50];
    uint16  padding2;
    uint32  wakeup_reason; // 0 = hibernation, 1 = USB, 2 = RDP
    wchar   os_version[256];
};

struct SystemInfoPOSIX     // sizeof=0x478
{
    uint32  job_id;        // 0x20005 = POSIX
    char    bot_id[16];
    char    unused1[24];
    char    hostname[128];
    char    username[114];
    char    ip_address[40];
    char    timezone[100];
    char    arch[100];
    char    memory[100];
    char    unused2[6];
    char    os_version[512];
};

Listing 2: ThemeForestRAT system information structure that is sent after establishing a C2 session

Listing 2 shows the structure definitions that ThemeForestRAT uses for sending system information when establishing a C2 session. The job_id field indicates the OS type, 0x10005 for Windows, and 0x20005 for both Linux and macOS as they share the same structure.

Configuration

The configuration file of ThemeForestRAT is encrypted with RC4 using the hex-encoded key 201A192D838F4853E300 and contains the following settings:

• 64-bit unique bot ID
• List of ten C2 server URLs
• Command interpreter, for example cmd.exe (not used)
• List of optional commands to execute under the user of the active console session (Windows only, empty by default)
• Matching array to enable the optional console command
• Last check-in timestamp
• Hibernation time between C2 sessions in minutes, default value is 3
• C2 callback settings, for example to immediately check in on a new active RDP connection

The configuration can be parsed using the C structure definition from Listing 3.

struct ThemeForestC2Config
{
    uint64  bot_id;
    wchar   urls[10][1024];
    wchar   shell[1024];
    wchar   wts_console_cmdline[10][1024];
    char    wts_console_cmdline_enabled[10];
    uint32  last_checkin_epoch;
    uint32  configured_hibernate_minutes;
    uint32  active_hibernate_minutes;
    uint16  callback_settings;
};

Listing 3: ThemeForestRAT configuration structure definition for Windows

The configuration path that the RAT reads from disk is hardcoded. On macOS and Linux, this is an absolute path, while on Windows it looks in the current working directory where the RAT is launched. In Table 3 we list the observed configuration paths and hardcoded configuration file sizes for ThemeForestRAT.

Command and Control

ThemeForestRAT communicates over HTTP(S). The filenames it uses for retrieving commands from the C2 server are prefixed with ThemeForest_. The response data is sent back to the operator as a file prefixed with Thumb_, see Figure 6. On Windows it uses the Ryeol Http Client²⁸ library for HTTP communications, and on macOS and Linux it uses libcurl. ThemeForestRAT has a single hardcoded C2 in the binary, but its configuration can be updated by sending the SetInfo command.

Commands

In terms of command functionality, ThemeForestRAT supports over twenty commands, at least twice as much as PondRAT. The Linux and macOS versions contain debug symbols, which allows us to map the command IDs to function names where available.

Note that the symbol names in Table 4 that start with CServer:: are from the debug symbols and the other names are deduced based on analysis of the command.

Shellcode Injection

On Windows, the CServer::OnInjectShellcode command injects shellcode into a given process ID using NtOpenProcess, NtAllocateVirtualMemory, NtWriteVirtualMemory and RtlCreateUserThread Windows API calls. The shellcode is encrypted using the same algorithm used in PerfhLoader (see Listing 1). In the macOS and Linux samples we have analysed, this command is defined as an empty stub.

RomeoGolf’s Little Brother

In 2016, Novetta released a detailed report called Operation Blockbuster²⁹, in which a Novetta-led coalition of security companies analysed malware samples from multiple cybersecurity incidents. The investigation linked the 2014 Sony Pictures attack to the Lazarus Group and revealed that the same actor had been behind numerous other attacks against government, military, and commercial targets using related malware since 2009.

Operation Blockbuster’s malware report describes RomeoGolf, a RAT that resembles ThemeForestRAT in several ways:

• Uses the temporary folder Z802056, although not used in ThemeForestRAT, is still created
• Overlapping command IDs and functionality
• Same unique identifier generation using 4 calls to rand()
• Configuration file with extension *.inf on Windows
• Timestomping of the configuration file based on mspaint.exe
• Two signalling threads for USB and RDP events

Figure 10 shows the RomeoGolf startup logic for generating its bot ID and two signalling threads that is identical to ThemeForestRAT (see Figure 5).

As can be seen in Table 5, the functionality to detect and copy data from newly attached logical drives has been removed in ThemeForestRAT, while leaving the temporary directory creation intact. Also, the thread to check for new RDP sessions has been extended in ThemeForestRAT to optionally spawn up to ten extra configured commands under the user of the active physical console session.

While RomeoGolf used Fake TLS³⁰ and its own custom server for its C2 communications, ThemeForestRAT uses the HTTP protocol and shared hosting for its C2 servers.

Onto the next stage with RemotePE

In the 2024 incident response case, we observed the actor cleaning up PondRAT and ThemeForestRAT, to deploy a more advanced RAT, which we named RemotePE. RemotePE is retrieved from a C2 server by RemotePELoader. RemotePELoader is encrypted on disk using Window’s Data Protection API (DPAPI) and is loaded by DPAPILoader. Using DPAPI enables environmental keying and makes it difficult to recover the original payload without access to the machine. DPAPILoader was made persistent through a created Windows service.

In Figure 10, we show a RemotePELoader check-in request used to retrieve RemotePE from the C2 server. RemotePE is written in C++ and is more advanced and elegant. We think that the actor uses this more sophisticated RAT for interesting or high-value targets that require a higher degree of operational security. Interestingly, it too uses the file renaming strategy PondRAT and POOLRAT Windows samples implement, except it skips the last random iteration.

We will publish a more thorough analysis of RemotePE in a future blogpost.

Summary

This blog is about a Lazarus subgroup that we have encountered multiple times during incident response engagements. This is a capable, patient, financially motivated actor who remains a legitimate threat.

We first discussed an incident response case from 2024, where this actor impersonated employees of trading companies to establish contact with potential victims. Though the method of achieving initial access remains unknown, we suspect a Chrome zero-day was used.

After initial access, two RATs were used in combination: PondRAT and ThemeForestRAT. Though PondRAT has already been discussed, there are no public analyses of ThemeForestRAT at the time of writing. For persistence, phantom DLL loading was used in conjunction with a custom loader called PerfhLoader.

PondRAT is a primitive RAT that provides little flexibility, however, as an initial payload it achieves its purpose. It has similarities with POOLRAT/SimpleTea. For more complex tasks, the actor uses ThemeForestRAT, which has more functionality and stays under the radar as it is loaded into memory only.

Lastly, we found the actor replaced ThemeForestRAT and PondRAT with the more advanced RemotePE. A detailed analysis of RemotePE will be published in the near future. So, stay tuned!

In Table 6 and 7, we list indicators of compromise related to the incident response cases we investigated and other artifacts we link to this actor.

Incident Response Support

If you have any questions or need assistance based on these findings, please contact Fox-IT CERT at cert@fox-it.com. For urgent matters, call 0800-FOXCERT (0800-3692378) within the Netherlands, or +31152847999 internationally to reach one of our incident responders.

Indicators of Compromise

YARA rules

import "pe"

rule Lazarus_DPAPILoader_Hunting {
  meta:
    description = "Hunting rule to detect DPAPILoader, a loader used to load RemotePE."
    author      = "Fox-IT / NCC Group"

  strings:
    $msg_1 = "[!] Could not allocate memory at the desired base!\n"
    $msg_2 = "[!] Virtual section size is out ouf bounds: "
    $msg_3 = "[!] Invalid relocDir pointer\n"
    $msg_4 = "[-] Not supported relocations format at %d: %d\n"
    $msg_5 = "[!] Cannot fill imports into 32 bit PE via 64 bit loader!\n"

  condition:
    any of them and pe.imports("Crypt32.dll", "CryptUnprotectData")
}

rule Lazarus_RemotePE_C2_strings {
  meta:
    description = "RemotePE strings used for C2."
    author      = "Fox-IT / NCC Group"

  strings:
    $a = "MicrosoftApplicationsTelemetryDeviceId" wide ascii xor
    $b = "armAuthorization" wide ascii xor
    $c = "ai_session" wide ascii xor

  condition:
    uint16(0) == 0x5A4D and all of them
}

rule Lazarus_RemotePE_class_strings {
  meta:
    description = "RemotePE class strings."
    author      = "Fox-IT / NCC Group"

  strings:
    $a = "IMiddleController" ascii wide xor
    $b = "IChannelController" ascii wide xor
    $c = "IConfigProfile" ascii wide xor
    $d = "IKernelModule" ascii wide xor

  condition:
    all of them
}

rule Lazarus_PerfhLoader_XOR_key {
  meta:
    description = "XOR key used for shellcode obfuscation."
    author      = "Fox-IT / NCC Group"

  strings:
    $mov_1  = { C7 [1-3] 00 01 02 03 }
    $mov_2  = { C7 [1-3] 04 05 06 07 }
    $mov_3  = { C7 [1-3] 08 09 0A 0B }
    $mov_4  = { C7 [1-3] 0C 0D 0E 0F }
    $init_1 = { 41 8D ?? FD 41 8D ?? F9 }

  condition:
    all of them
}

rule Lazarus_ThemeForestRAT_C2_strings {
  meta:
    description = "ThemeForestRAT strings used for C2."
    author      = "Fox-IT / NCC Group"

  strings:
    $themeforest = "ThemeForest_%s" ascii wide
    $thumb       = "Thumb_%s" ascii wide
    $param_code  = "code" ascii wide
    $param_fn    = "fn" ascii wide
    $param_ldf   = "ldf" ascii wide

  condition:
    all of them
}

rule Lazarus_ThemeForestRAT_RC4_key {
  meta:
    description = "ThemeForest RC4 key used for config file."
    author      = "Fox-IT / NCC Group"

  strings:
    $rc4_key     = { 20 1A 19 2D 83 8F 48 53 E3 00 }
    $rc4_key_mov = { 20 1A 19 2D [2-8] 83 8F 48 53 [2-10] E3 00 }

  condition:
    any of them
}

References

Statistics across all threats

The percentage of ICS computers on which malicious objects were blocked has been decreasing since the beginning of 2024. In Q4 2025, it was 19.7%. Over the past three years, the percentage has decreased by 1.36 times, and by 1.25 times since Q4 2023.

Percentage of ICS computers on which malicious objects were blocked, Q1 2023–Q4 2025

Regionally, in Q4 2025, the percentage of ICS computers on which malicious objects were blocked ranged from 8.5% in Northern Europe to 27.3% in Africa.

Regions ranked by percentage of ICS computers on which malicious objects were blocked

Four regions saw an increase in the percentage of ICS computers on which malicious objects were blocked. The most notable increases occurred in Southern Europe and South Asia. In Q3 2025, East Asia experienced a sharp increase triggered by the local spread of malicious scripts, but the figure has since returned to normal.

Changes in percentage of ICS computers on which malicious objects were blocked, Q4 2025

Feature of the quarter: worms in email

In Q4 2025, the percentage of ICS computers on which wormsinemailattachments were blocked increasedinallregions of the world.

Many of the blocked threats were related to the worm Backdoor.MSIL.XWorm. This malware is designed to persist on the system and then remotely control it.

Interestingly, this threat was not detected on ICS computers in the previous quarter, yet it appeared in all regions in Q4 2025.

A study found that the active spread of Backdoor.MSIL.XWorm via phishing emails was likely linked to the use by hackers of another malware obfuscation technique that was actively used during massive phishing campaigns in Q4 2025. These campaigns have been known since 2024 as “Curriculum-vitae-catalina”.

The attackers distributed phishing emails to HR managers, recruiters, and employees responsible for hiring. The messages were disguised as responses from job applicants with subjects such as “Resume” or “Attached Resume” and contained a malicious executable file under the guise of a curriculum vitae. Typically, the file was named Curriculum Vitae-Catalina.exe. When executed, it infected the system.

In Q4 2025, the threat spread across regions in two waves — one in October and another in November. Russia, Western Europe, South America, and North America (Canada) were attacked in October. A spike in Backdoor.MSIL.XWorm blocking was observed in other regions in November. The attack subsided in all regions in December.

The highest percentage of ICS computers on which Backdoor.MSIL.XWorm was blocked was observed in regions where threats from email clients had been historically blocked at high rates on ICS computers: Southern Europe, South America, and the Middle East.

At the same time, in Africa, where USB storage media are still actively used, the threat was also detected when removable devices were connected to ICS computers.

Selected industries

The biometrics sector has historically led the rankings of industries and OT infrastructures surveyed in this report in terms of the percentage of ICS computers on which malicious objects were blocked.

These systems are characterized by accessibility to and from the internet, as well as minimal cybersecurity controls by the consumer organization.

Rankings of industries and OT infrastructure by percentage of ICS computers on which malicious objects were blocked

In Q4 2025, the percentage of ICS computers on which malicious objects were blocked increased only in one sector: oil and gas. The corresponding figures increased in two regions: Russia, and Central Asia and the South Caucasus.

However, if we look at a broader time span, there is a downward trend in all the surveyed industries.

Percentage of ICS computers on which malicious objects were blocked in selected industries

Diversity of detected malicious objects

In Q4 2025, Kaspersky protection solutions blocked malware from 10,142 different malware families of various categories on industrial automation systems.

Percentage of ICS computers on which the activity of malicious objects from various categories was blocked

In Q4 2025, there was an increase in the percentage of ICS computers on which worms, and miners in the form of executable files for Windows were blocked. These were the only categories that exhibited an increase.

Main threat sources

Depending on the threat detection and blocking scenario, it is not always possible to reliably identify the source. The circumstantial evidence for a specific source can be the blocked threat’s type (category).

The internet (visiting malicious or compromised internet resources; malicious content distributed via messengers; cloud data storage and processing services and CDNs), email clients (phishing emails), and removable storage devices remain the primary sources of threats to computers in an organization’s technology infrastructure.

In Q4 2025, the percentage of ICS computers on which malicious objects from various sources were blocked decreased. All sources except email clients saw their lowest levels in three years.

Percentage of ICS computers on which malicious objects from various sources were blocked

The same computer can be attacked by several categories of malware from the same source during a quarter. That computer is counted when calculating the percentage of attacked computers for each threat category, but is only counted once for the threat source (we count unique attacked computers). In addition, it is not always possible to accurately determine the initial infection attempt. Therefore, the total percentage of ICS computers on which various categories of threats from a certain source were blocked can exceed the percentage of computers affected by the source itself.

• In Q4 2025, the percentage of ICS computers on which threats from the internet were blocked decreased to 7.67% and reached its lowest level since the beginning of 2023. The main categories of internet threats are malicious scripts and phishing pages, and denylisted internet resources. The percentage ranged from 3.96% in Northern Europe to 11.33% in South Asia.
• The main categories of threats from email clients blocked on ICS computers were malicious scripts and phishing pages, spyware, and malicious documents. Most of the spyware detected in phishing emails was delivered as a password archive or a multi-layered script embedded in office document files. The percentage of ICS computers on which threats from email clients were blocked ranged from 0.64% in Northern Europe to 6.34% in Southern Europe.
• The main categories of threats that were blocked when removable media was connected to ICS computers were worms, viruses, and spyware. The percentage of ICS computers on which threats from removable media were blocked ranged from 0.05% in Australia and New Zealand to 1.41% in Africa.
• The main categories of threats that spread through network folders in Q4 2025 were viruses, AutoCAD malware, worms, and spyware. The percentage of ICS computers on which threats from network folders were blocked ranged from 0.01% in Northern Europe to 0.18% in East Asia.

Threat categories

Typical attacks blocked within an OT network are multi-step sequences of malicious activities, where each subsequent step of the attackers is aimed at increasing privileges and/or gaining access to other systems by exploiting the security problems of industrial enterprises, including OT infrastructures.

Malicious objects used for initial infection

In Q4 2025, the percentage of ICS computers on which denylisted internet resources were blocked decreased to 3.26%. This is the lowest quarterly figure since the beginning of 2022, and it has decreased by 1.8 times since Q2 2025.

Percentage of ICS computers on which denylisted internet resources were blocked, Q1 2023–Q4 2025

Regionally, the percentage of ICS computers on which denylisted internet resources were blocked ranged from 1.74% in Northern Europe to 3.93% in Southeast Asia, which displaced Africa from first place. Russia rounded out the top three regions for this indicator.

The percentage of ICS computers on which malicious documents were blocked increased for three consecutive quarters. However, in Q4 2025 it decreased by 0.22 pp to 1.76%.

Percentage of ICS computers on which malicious documents were blocked, Q1 2023–Q4 2025

Regionally, the percentage ranged from 0.46% in Northern Europe to 3.82% in Southern Europe. In Q4 2025, the indicator increased in Eastern Europe, Russia, and Western Europe.

The percentage of ICS computers on which malicious scripts and phishing pages were blocked decreased to 6.58%. Despite the decline, this category led the rankings of threat categories in terms of the percentage of ICS computers on which they were blocked.

Percentage of ICS computers on which malicious scripts and phishing pages were blocked, Q1 2023–Q4 2025

Regionally, the percentage ranged from 2.52% in Northern Europe to 10.50% in South Asia. The indicator increased in South Asia, South America, Southern Europe, and Africa. South Asia saw the most notable increase, at 3.47 pp.

Next-stage malware

Malicious objects used to initially infect computers deliver next-stage malware — spyware, ransomware, and miners — to victims’ computers. As a rule, the higher the percentage of ICS computers on which the initial infection malware is blocked, the higher the percentage for next-stage malware.

In Q4 2025, the percentage of ICS computers on which spyware, ransomware and web miners were blocked decreased. The rates were:

• Spyware: 3.80% (down 0.24 pp). For the second quarter in a row, spyware took second place in the rankings of threat categories in terms of the percentage of ICS computers on which it was blocked.
• Ransomware: 0.16% (down 0.01 pp).
• Web miners: 0.24% (down 0.01 pp), this is the lowest level observed thus far in the period under review.

The percentage of ICS computers on which miners in the form of executable files for Windows were blocked increased to 0.60% (up 0.03 pp).

Self-propagating malware

Self-propagating malware (worms and viruses) is a category unto itself. Worms and virus-infected files were originally used for initial infection, but as botnet functionality evolved, they took on next-stage characteristics.

To spread across ICS networks, viruses and worms rely on removable media and network folders and are distributed in the form of infected files, such as archives with backups, office documents, pirated games and hacked applications. In rarer and more dangerous cases, web pages with network equipment settings, as well as files stored in internal document management systems, product lifecycle management (PLM) systems, resource management (ERP) systems and other web services are infected.

In Q4 2025, the percentage of ICS computers on which worms were blocked increased by 1.6 times to 1.60%. As mentioned above, this increase is related to a global phishing attack that spread the Backdoor.MSIL.XWorm backdoor worm across all regions of the world. The percentage increased in all regions. The biggest increase (up by 2.16 times) was in Southern Europe. The malware was primary distributed through email clients, and Southern Europe led the way in terms of the percentage of ICS computers on which threats from email clients were blocked.

The percentage of ICS computers on which viruses were blocked decreased to 1.33%.

AutoCAD malware

This category of malware can spread in a variety of ways, so it does not belong to a specific group.

After an increase in the previous quarter, the percentage of ICS computers on which AutoCAD malware was blocked decreased to 0.29% in Q4 2025.

For more information on industrial threats see the full version of the report.

Statistics across all threats

The percentage of ICS computers on which malicious objects were blocked has been decreasing since the beginning of 2024. In Q4 2025, it was 19.7%. Over the past three years, the percentage has decreased by 1.36 times, and by 1.25 times since Q4 2023.

Percentage of ICS computers on which malicious objects were blocked, Q1 2023–Q4 2025

Regionally, in Q4 2025, the percentage of ICS computers on which malicious objects were blocked ranged from 8.5% in Northern Europe to 27.3% in Africa.

Regions ranked by percentage of ICS computers on which malicious objects were blocked

Four regions saw an increase in the percentage of ICS computers on which malicious objects were blocked. The most notable increases occurred in Southern Europe and South Asia. In Q3 2025, East Asia experienced a sharp increase triggered by the local spread of malicious scripts, but the figure has since returned to normal.

Changes in percentage of ICS computers on which malicious objects were blocked, Q4 2025

Feature of the quarter: worms in email

In Q4 2025, the percentage of ICS computers on which wormsinemailattachments were blocked increasedinallregions of the world.

Many of the blocked threats were related to the worm Backdoor.MSIL.XWorm. This malware is designed to persist on the system and then remotely control it.

Interestingly, this threat was not detected on ICS computers in the previous quarter, yet it appeared in all regions in Q4 2025.

A study found that the active spread of Backdoor.MSIL.XWorm via phishing emails was likely linked to the use by hackers of another malware obfuscation technique that was actively used during massive phishing campaigns in Q4 2025. These campaigns have been known since 2024 as “Curriculum-vitae-catalina”.

The attackers distributed phishing emails to HR managers, recruiters, and employees responsible for hiring. The messages were disguised as responses from job applicants with subjects such as “Resume” or “Attached Resume” and contained a malicious executable file under the guise of a curriculum vitae. Typically, the file was named Curriculum Vitae-Catalina.exe. When executed, it infected the system.

In Q4 2025, the threat spread across regions in two waves — one in October and another in November. Russia, Western Europe, South America, and North America (Canada) were attacked in October. A spike in Backdoor.MSIL.XWorm blocking was observed in other regions in November. The attack subsided in all regions in December.

The highest percentage of ICS computers on which Backdoor.MSIL.XWorm was blocked was observed in regions where threats from email clients had been historically blocked at high rates on ICS computers: Southern Europe, South America, and the Middle East.

At the same time, in Africa, where USB storage media are still actively used, the threat was also detected when removable devices were connected to ICS computers.

Selected industries

The biometrics sector has historically led the rankings of industries and OT infrastructures surveyed in this report in terms of the percentage of ICS computers on which malicious objects were blocked.

These systems are characterized by accessibility to and from the internet, as well as minimal cybersecurity controls by the consumer organization.

Rankings of industries and OT infrastructure by percentage of ICS computers on which malicious objects were blocked

In Q4 2025, the percentage of ICS computers on which malicious objects were blocked increased only in one sector: oil and gas. The corresponding figures increased in two regions: Russia, and Central Asia and the South Caucasus.

However, if we look at a broader time span, there is a downward trend in all the surveyed industries.

Percentage of ICS computers on which malicious objects were blocked in selected industries

Diversity of detected malicious objects

In Q4 2025, Kaspersky protection solutions blocked malware from 10,142 different malware families of various categories on industrial automation systems.

Percentage of ICS computers on which the activity of malicious objects from various categories was blocked

In Q4 2025, there was an increase in the percentage of ICS computers on which worms, and miners in the form of executable files for Windows were blocked. These were the only categories that exhibited an increase.

Main threat sources

Depending on the threat detection and blocking scenario, it is not always possible to reliably identify the source. The circumstantial evidence for a specific source can be the blocked threat’s type (category).

The internet (visiting malicious or compromised internet resources; malicious content distributed via messengers; cloud data storage and processing services and CDNs), email clients (phishing emails), and removable storage devices remain the primary sources of threats to computers in an organization’s technology infrastructure.

In Q4 2025, the percentage of ICS computers on which malicious objects from various sources were blocked decreased. All sources except email clients saw their lowest levels in three years.

Percentage of ICS computers on which malicious objects from various sources were blocked

The same computer can be attacked by several categories of malware from the same source during a quarter. That computer is counted when calculating the percentage of attacked computers for each threat category, but is only counted once for the threat source (we count unique attacked computers). In addition, it is not always possible to accurately determine the initial infection attempt. Therefore, the total percentage of ICS computers on which various categories of threats from a certain source were blocked can exceed the percentage of computers affected by the source itself.

• In Q4 2025, the percentage of ICS computers on which threats from the internet were blocked decreased to 7.67% and reached its lowest level since the beginning of 2023. The main categories of internet threats are malicious scripts and phishing pages, and denylisted internet resources. The percentage ranged from 3.96% in Northern Europe to 11.33% in South Asia.
• The main categories of threats from email clients blocked on ICS computers were malicious scripts and phishing pages, spyware, and malicious documents. Most of the spyware detected in phishing emails was delivered as a password archive or a multi-layered script embedded in office document files. The percentage of ICS computers on which threats from email clients were blocked ranged from 0.64% in Northern Europe to 6.34% in Southern Europe.
• The main categories of threats that were blocked when removable media was connected to ICS computers were worms, viruses, and spyware. The percentage of ICS computers on which threats from removable media were blocked ranged from 0.05% in Australia and New Zealand to 1.41% in Africa.
• The main categories of threats that spread through network folders in Q4 2025 were viruses, AutoCAD malware, worms, and spyware. The percentage of ICS computers on which threats from network folders were blocked ranged from 0.01% in Northern Europe to 0.18% in East Asia.

Threat categories

Typical attacks blocked within an OT network are multi-step sequences of malicious activities, where each subsequent step of the attackers is aimed at increasing privileges and/or gaining access to other systems by exploiting the security problems of industrial enterprises, including OT infrastructures.

Malicious objects used for initial infection

In Q4 2025, the percentage of ICS computers on which denylisted internet resources were blocked decreased to 3.26%. This is the lowest quarterly figure since the beginning of 2022, and it has decreased by 1.8 times since Q2 2025.

Percentage of ICS computers on which denylisted internet resources were blocked, Q1 2023–Q4 2025

Regionally, the percentage of ICS computers on which denylisted internet resources were blocked ranged from 1.74% in Northern Europe to 3.93% in Southeast Asia, which displaced Africa from first place. Russia rounded out the top three regions for this indicator.

The percentage of ICS computers on which malicious documents were blocked increased for three consecutive quarters. However, in Q4 2025 it decreased by 0.22 pp to 1.76%.

Percentage of ICS computers on which malicious documents were blocked, Q1 2023–Q4 2025

Regionally, the percentage ranged from 0.46% in Northern Europe to 3.82% in Southern Europe. In Q4 2025, the indicator increased in Eastern Europe, Russia, and Western Europe.

The percentage of ICS computers on which malicious scripts and phishing pages were blocked decreased to 6.58%. Despite the decline, this category led the rankings of threat categories in terms of the percentage of ICS computers on which they were blocked.

Percentage of ICS computers on which malicious scripts and phishing pages were blocked, Q1 2023–Q4 2025

Regionally, the percentage ranged from 2.52% in Northern Europe to 10.50% in South Asia. The indicator increased in South Asia, South America, Southern Europe, and Africa. South Asia saw the most notable increase, at 3.47 pp.

Next-stage malware

Malicious objects used to initially infect computers deliver next-stage malware — spyware, ransomware, and miners — to victims’ computers. As a rule, the higher the percentage of ICS computers on which the initial infection malware is blocked, the higher the percentage for next-stage malware.

In Q4 2025, the percentage of ICS computers on which spyware, ransomware and web miners were blocked decreased. The rates were:

• Spyware: 3.80% (down 0.24 pp). For the second quarter in a row, spyware took second place in the rankings of threat categories in terms of the percentage of ICS computers on which it was blocked.
• Ransomware: 0.16% (down 0.01 pp).
• Web miners: 0.24% (down 0.01 pp), this is the lowest level observed thus far in the period under review.

The percentage of ICS computers on which miners in the form of executable files for Windows were blocked increased to 0.60% (up 0.03 pp).

Self-propagating malware

Self-propagating malware (worms and viruses) is a category unto itself. Worms and virus-infected files were originally used for initial infection, but as botnet functionality evolved, they took on next-stage characteristics.

To spread across ICS networks, viruses and worms rely on removable media and network folders and are distributed in the form of infected files, such as archives with backups, office documents, pirated games and hacked applications. In rarer and more dangerous cases, web pages with network equipment settings, as well as files stored in internal document management systems, product lifecycle management (PLM) systems, resource management (ERP) systems and other web services are infected.

In Q4 2025, the percentage of ICS computers on which worms were blocked increased by 1.6 times to 1.60%. As mentioned above, this increase is related to a global phishing attack that spread the Backdoor.MSIL.XWorm backdoor worm across all regions of the world. The percentage increased in all regions. The biggest increase (up by 2.16 times) was in Southern Europe. The malware was primary distributed through email clients, and Southern Europe led the way in terms of the percentage of ICS computers on which threats from email clients were blocked.

The percentage of ICS computers on which viruses were blocked decreased to 1.33%.

AutoCAD malware

This category of malware can spread in a variety of ways, so it does not belong to a specific group.

After an increase in the previous quarter, the percentage of ICS computers on which AutoCAD malware was blocked decreased to 0.29% in Q4 2025.

For more information on industrial threats see the full version of the report.

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