Kaspersky Links Head Mare to Twelve, Targeting Russian Entities via Shared C2 Servers
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-26855 | Unauthenticated SSRF/RCE in Microsoft Exchange Server (ProxyLogon) CVE-2021-26855 is a server-side request forgery flaw (CWE-918) in Microsoft Exchange Server that allows an unauthenticated remote attacker to send specially crafted HTTP requests and have the Exchange server process them as itself, disclosing sensitive session information. When chained with sibling Exchange flaws (the 'ProxyLogon' chain), it yields authentication bypass and arbitrary file write, escalating to full remote code execution with SYSTEM-level privileges on the on-premises Exchange server. Any organization running an affected on-premises Exchange server reachable over HTTP/HTTPS (typically outbound webmail) is exposed; Exchange Online was not affected. Exploitation is confirmed in the wild at large scale: the flaw was mass-exploited beginning in early 2021 (notably by the HAFNIUM group), is on the CISA KEV with documented ransomware use, and has a maximum EPSS score of 100% (100th percentile), despite no public PoC listing. Do: Apply the vendor's March 2021 Exchange security updates (or later cumulative updates) immediately, per the CISA required action; until patched, limit Exchange (ECP/OWA) exposure to the internet via firewall/VPN rules. Hunt for compromise: review IIS logs for unrecognized authenticated activity against FrontEnd HttpProxy endpoints, and check for malicious files or webshells under inetpub\wwwroot\aspnet_client, given the known ransomware use. | 9.1 | 100% | KEV ransomware PoC ×4 |
| masshundreds of thousands of on-premises deployments; tens of thousands of internet-exposed Exchange servers | |
| CVE-2023-38831 | Code Execution in RARLAB WinRAR via Crafted ZIP File/Folder Name Confusion RARLAB WinRAR before 6.23 mishandles ZIP archives that contain a benign file (such as a JPG) alongside a folder with the same name, causing the folder's contents - which can include malicious executable files - to be processed when the user merely attempts to view the benign file. By sending a crafted ZIP archive, an attacker gains arbitrary code execution on the victim's machine with the user's privileges. Because the flaw is local (AV:L) and requires user interaction, risk is limited to Windows systems running an unpatched copy of WinRAR, while machines without the tool are unaffected. The bug was actively exploited in the wild from April through October 2023, including by government-backed actors (APT28), SideCopy attacks on Indian government entities, ransomware operations, and trading-account theft campaigns, and it was added to CISA's Known Exploited Vulnerabilities catalog on 2023-08-24. Do: Upgrade all Windows systems running WinRAR to version 6.23 or later, which fixes this flaw; if patching is not immediately possible, treat ZIP files from untrusted sources with caution and check archives for duplicate file/folder names before opening. Given KEV listing with known ransomware use and public proof-of-concept exploits, hunt for compromise by reviewing whether unexpected executables or scripts ran when ZIP archives were opened, and apply vendor mitigations per CISA's required action or discontinue use if mitigations are unavailable. | 7.8 | 98% | KEV ransomware PoC ×4 |
| masshundreds of millions of users/installations worldwide (WinRAR is one of the most widely installed Windows archive utilities) |
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Two known threat activity clusters codenamed Head Mare and Twelve have likely joined forces to target Russian entities, new findings from Kaspersky reveal.
"Head Mare relied heavily on tools previously associated with Twelve. Additionally, Head Mare attacks utilized command-and-control (C2) servers exclusively linked to Twelve prior to these incidents," the company said. "This suggests potential collaboration and joint campaigns between the two groups."
Both Head Mare and Twelve were previously documented by Kaspersky in September 2024, with the former leveraging a now-patched vulnerability in WinRAR (CVE-2023-38831) to obtain initial access and deliver malware and in some cases, even deploy ransomware families like LockBit for Windows and Babuk for Linux (ESXi) in exchange for a ransom.
Twelve, on the other hand, has been observed staging destructive attacks, taking advantage of various publicly available tools to encrypt victims' data and irrevocably destroy their infrastructure with a wiper to prevent recovery efforts.
Kaspersky's latest analysis shows Head Mare's use of two new tools, including CobInt, a backdoor used by ExCobalt and Crypt Ghouls in attacks aimed at Russian firms in the past, as well as a bespoke implant named PhantomJitter that's installed on servers for remote command execution.
The deployment of CobInt has also been observed in attacks mounted by Twelve, with overlaps uncovered between the hacking crew and Crypt Ghouls, indicating some kind of tactical connection between different groups currently targeting Russia.
Other initial access pathways exploited by Head Mare include the abuse of other known security flaws in Microsoft Exchange Server (e.g., CVE-2021-26855 aka ProxyLogon), as well as via phishing emails bearing rogue attachments and compromising contractors' networks to infiltrate victim infrastructure, a technique known as the trusted relationship attack.
"The attackers used ProxyLogon to execute a command to download and launch CobInt on the server," Kaspersky said, highlighting the use of an updated persistence mechanism that eschews scheduled tasks in favor of creating new privileged local users on a business automation platform server. These accounts are then used to connect to the server via RDP to transfer and execute tools interactively.
Besides assigning the malicious payloads names that mimic benign operating system files (e.g., calc.exe or winuac.exe), the threat actors have been found to remove traces of their activity by clearing event logs and use proxy and tunneling tools like Gost and Cloudflared to conceal network traffic.
Some of the other utilities used are -
- quser.exe, tasklist.exe, and netstat.exe for system reconnaissance
- fscan and SoftPerfect Network Scanner for local network reconnaissance
- ADRecon for gathering information from Active Directory
- Mimikatz, secretsdump, and ProcDump for credential harvesting
- RDP for lateral movement
- mRemoteNG, smbexec, wmiexec, PAExec, and PsExec for remote host communication
- Rclone for data transfer
The attacks culminate with the deployment of LockBit 3.0 and Babuk ransomware on compromised hosts, followed by dropping a note that urges victims to contact them on Telegram for decrypting their files.
"Head Mare is actively expanding its set of techniques and tools," Kaspersky said. "In recent attacks, they gained initial access to the target infrastructure by not only using phishing emails with exploits but also by compromising contractors. Head Mare is working with Twelve to launch attacks on state- and privately-controlled companies in Russia."
The development comes as BI.ZONE linked the North Korea-linked threat actor known as ScarCruft (aka APT37, Reaper, Ricochet Chollima, and Squid Werewolf) to a phishing campaign directed against an unnamed Russian industrial entity in December 2024 that delivered a malware loader responsible for deploying an unknown payload from a remote server.
The activity, the Russian company said, closely resembles another campaign dubbed SHROUDED#SLEEP that Securonix documented in October 2024 as leading to the deployment of a backdoor referred to as VeilShell in intrusions targeting Cambodia and likely other Southeast Asian countries.
Last month, BI.ZONE also detailed continued cyber attacks staged by Bloody Wolf to deliver NetSupport RAT as part of a campaign that has compromised more than 400 systems in Kazakhstan and Russia, marking a shift from STRRAT.
Update
Kasperksky, in a follow-up report published on March 28, 2025, said it detected a new wave of cyber attacks carried out by Head Mare on various Russian industrial enterprises.
"In March 2025, more than 800 employees from about a hundred organizations received a mailing containing previously unknown malware," the company said. "The attackers' targets included the instrument-making and mechanical engineering industries."
The attacks involved sending emails with ZIP attachments that, when opened, contains a seemingly innocuous document, but, in reality, is a polyglot file that executes a new Python-based backdoor dubbed PhantomPyramid. Also deployed is MeshAgent, an open-source remote device management tool previously observed in Awaken Likho attacks aimed at Russia.
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