US Agencies Update Medusa Ransomware Warning As Victim Count Surpasses 500

U.S. Cybersecurity and Infrastructure Security Agency CISA and law-enforcement have issued an expanded warning about the Medusa ransomware operation after federal investigations identified more than 500 affected organisations across critical infrastructure and other industries.

The updated joint advisory, published on August 18 by the Cybersecurity and Infrastructure Security Agency, the FBI and the Department of Health and Human Services, incorporates tactics, techniques, procedures and indicators of compromise observed in FBI investigations as recently as April 2026.