LockBit 3 Black

Ragnarök: F6 Investigates VantaCore Ransomware Attacks and Suspected Thor Rebrand

F6's Digital Forensics Laboratory has identified a new ransomware group called VantaCore that has struck at least seven Russian organizations with multimillion-dollar ransom demands. Researchers assess VantaCore as a rebrand of the previously known pro-Ukrainian Thor group, part of a broader consolidation among such actors in 2025–2026. The group abandoned LockBit 3 Black and Babuk in favor of its own VantaCore ransomware built on similar foundations, while deploying custom tools including VantaCoreLoader, VantaCoreRAT, and the SnowKiller BYOVD utility. VantaCore maintains a Tor-based data leak site launched no later than June 2026 and uses double and triple extortion tactics, selling or publicly releasing stolen data after encryption. Initial access relies on exposed RDP, VPN, public application vulnerabilities, and compromised partner credentials, followed by lateral movement via legitimate accounts and SMB/RDP. The group disables security products, clears logs, and destroys backups using Bootice before deploying its ChaCha20/X25519 ransomware via manual RDP sessions or automated loaders.