Claude Skills ransomware deployment — MedusaLocker via malicious plugin
Date: 2025-12
Affected: Claude (Anthropic) — Skills plugin ecosystem
Attack vector: supply-chain
Category: red-team
Severity: Critical

Cato Networks demonstrated deploying MedusaLocker ransomware through Claude's Skills plugin by downloading, modifying, and re-uploading malicious Skills with autonomous execution capability.

Impact: Ransomware deployment capability; autonomous code execution; agent weaponization

Mitigations:
Runtime monitoring for destructive operations
Sandbox execution for agent plugins
Skill/plugin code review and signing

Architectural layers (MAESTRO):
label: Agent Ecosystem
notes: Malicious Skills plugin uploaded to agent marketplace
role: origin
label: Agent Frameworks
notes: Agent autonomously executes malicious skill code
role: propagation
label: Deployment & Infrastructure
notes: Ransomware deployed on host system via agent
role: impact