The Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), and the U.S. Department of Health and Human Services (HHS) issued an updated joint cybersecurity advisory on Medusa ransomware. Medusa, a ransomware-as-a-service variant first identified in June 2021, has impacted over 500 victims across critical infrastructure sectors, including healthcare, defense industrial base, critical manufacturing, government services, information technology, and financial services. The advisory provides technical details on Medusa’s tactics, detection guidance, and mitigation strategies for at-risk critical infrastructure organizations.
Medusa actors typically gain initial access through brokers, phishing campaigns, and exploitation of unpatched, internet-facing vulnerabilities, often employing legitimate tools and living-off-the-land techniques to evade detection. Once inside a network, the actors leverage remote monitoring and management software for lateral movement, credential access, data exfiltration, and ransomware deployment. CISA, FBI, and HHS urge organizations to implement key mitigations, including timely patching of known vulnerabilities, network segmentation to limit lateral movement, and filtering of network traffic to block untrusted access to internal remote services.
