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ATR-2026-00065highTool Poisoningexperimental

Malicious Skill Update or Mutation

Detects MCP skills that have been updated to introduce malicious behavior after initial trust was established. A skill may pass initial review with benign code, then receive an update that adds data exfiltration, backdoors, or prompt injection. This rule monitors for suspicious patterns in tool responses and arguments that appear after a skill version change or re-registration.

Severity
high
Category
Tool Poisoning
Scan Target
mcp
Author
ATR Community

Response Actions

block toolalertsnapshotescalate

References

OWASP Agentic
ASI04:2026 - Agentic Supply Chain Vulnerabilities
OWASP LLM
LLM03:2025 - Supply Chain Vulnerabilities
MITRE ATLAS
AML.T0010 - ML Supply Chain Compromise