New pro-Ukraine hacker group targets Russian companies with custom ransomware

Source: The Record A ransomware group believed to be linked to pro-Ukrainian hackers is targeting Russian organizations with custom malware and demanding multimillion-dollar payments.

The group calls itself VantaCore and has targeted at least seven known victims, Russian cybersecurity firm F6 said in a report. The group's data-leak website appears to have been created in June.

Researchers said they believe VantaCore is a rebrand of the hacking group Thor. F6 attributed at least 12 attacks to Thor in 2025. VantaCore operates as a ransomware-as-a-service operation, a business model in which ransomware developers provide malware and infrastructure to affiliates who carry out attacks.

VantaCore communicates with victims through a Tor-based chat service and maintains a leak site where stolen information can be published. Full Story