Google Ties Suspected Russian Actor to CANFAIL Malware Attacks on Ukrainian Orgs

A previously undocumented threat actor has been attributed to attacks targeting Ukrainian organizations with malware known as CANFAIL. Google Threat Intelligence Group (GTIG) described the hack group as possibly affiliated with Russian intelligence services.

The threat actor is assessed to have targeted defense, military, government, and energy organizations within the Ukrainian regional and national governments. However, the group has also exhibited growing interest in aerospace organizations, manufacturing companies with military and drone ties, nuclear and chemical research organizations, and international organizations involved in conflict monitoring and humanitarian aid in Ukraine, GTIG added.

"Despite being less sophisticated and resourced than other Russian threat groups, this actor recently began to overcome some technical limitations using LLMs [large language models]," GTIG said. "Through prompting, they conduct reconnaissance, create lures for social engineering, and seek answers to basic technical questions for post-compromise activity and C2 infrastructure setup."

Recent phishing campaigns have involved the threat actor impersonating legitimate national and local Ukrainian energy organizations to obtain unauthorized access to organizational and personal email accounts. The group is also said to have masqueraded as a Romanian energy company that works with customers in Ukraine, in addition to targeting a Romanian firm and conducting reconnaissance on Moldovan organizations.

To enable its operations, the threat actor generates email address lists tailored to specific regions and industries based on their research. The attack chains seemingly contain LLM-generated lures and embed Google Drive links pointing to a RAR archive containing CANFAIL malware. Typically disguised with a double extension to pass off as a PDF document (*.pdf.js), CANFAIL is an obfuscated JavaScript malware that's designed to execute a PowerShell script that, in turn, downloads and executes a memory-only PowerShell dropper. In parallel, it displays a fake "error" message to the victim.

Google said the threat actor is also linked to a campaign called PhantomCaptcha that was disclosed by SentinelOne SentinelLABS in October 2025 as targeting organizations associated with Ukraine's war relief efforts through phishing emails that direct recipients to fake pages hosting ClickFix-style instructions to activate the infection sequence and deliver a WebSocket-based trojan.

This attribution represents a significant development in understanding the evolving threat landscape targeting Ukraine, particularly as Russian-linked groups increasingly incorporate AI tools to enhance their capabilities despite resource limitations compared to more established threat actors.

Technical Analysis of CANFAIL Malware The CANFAIL malware employs several sophisticated techniques to evade detection and maintain persistence:

• Obfuscation: The JavaScript payload is heavily obfuscated to bypass static analysis tools
• Double Extension: Uses the *.pdf.js naming convention to appear as legitimate PDF documents
• PowerShell Dropper: Executes a memory-only PowerShell dropper to avoid writing malicious files to disk
• Fake Error Messages: Displays convincing error dialogs to distract victims during execution
• Google Drive Distribution: Leverages trusted cloud storage services to host malicious payloads

LLM Integration in Cyber Attacks The use of large language models by this threat actor marks a concerning evolution in cyber attack methodologies. By leveraging LLMs for:

• Automated reconnaissance of target organizations
• Generation of convincing phishing lures in multiple languages
• Technical troubleshooting during post-compromise activities
• Infrastructure setup and configuration guidance

The threat actor demonstrates how AI tools are democratizing certain aspects of cyber operations, potentially lowering the barrier to entry for sophisticated attacks.

Defense Recommendations Organizations in Ukraine and neighboring countries should implement the following protective measures:

1. Email Security: Deploy advanced email filtering that can detect suspicious Google Drive links and double-extension files
2. User Training: Educate employees about social engineering tactics, particularly those impersonating energy companies
3. Network Monitoring: Implement behavioral analytics to detect anomalous PowerShell activity and memory-only droppers
4. Multi-Factor Authentication: Require MFA for all email and critical system access
5. Threat Intelligence: Subscribe to threat feeds that provide indicators of compromise related to this actor

Broader Context This campaign is part of a larger pattern of cyber operations targeting Ukraine since the escalation of conflict in 2022. Russian-linked groups have consistently targeted critical infrastructure, government agencies, and organizations supporting Ukraine's defense efforts.

The integration of AI tools represents a tactical evolution rather than a strategic shift, as these groups continue to adapt their methodologies to overcome defensive measures and resource constraints.

For organizations concerned about similar threats, regular security assessments, employee training programs, and robust incident response planning remain essential components of a comprehensive cybersecurity strategy.