Medusa

Antivirus and endpoint security tools are increasingly challenged by ransomware groups that use sophisticated strategies to disable defenses early in attacks. Cisco Talos reported that in nearly half of the ransomware incidents they handled in 2024, attackers successfully employed "EDR killers" to neutralize endpoint detection and response (EDR) systems, achieving success 48 percent of the time. Tools such as EDRSilencer, EDRSandblast, EDRKillShifter, and Terminator pose significant threats to organizational security. EDRKillShifter exploits vulnerable drivers on Windows machines to terminate EDR products, a tactic observed in operations by rival gangs like Medusa, BianLian, and Play. The primary goal of these tools is to disable EDR protections, allowing attackers to operate undetected, complicating system recovery efforts. Recovery often requires wiping and rebuilding entire networks if robust backups are available. Some EDR killers, like HRSword, are legitimate software tools misused by ransomware actors to disable endpoint protection systems. Attackers have exploited misconfigured systems, particularly EDR products set to audit-only mode, which detect but do not block malicious activity. LockBit has remained the most active ransomware-as-a-service group for the third consecutive year, accounting for 16 percent of claimed attacks in 2024. Newcomer RansomHub secured the second position with 11 percent of posts to leak sites. The effectiveness of law enforcement actions plays a significant role in shaping the ransomware landscape.