Lethal Trifecta Threat Model: Private Data + Untrusted Content + External Egress = Maximum Risk
nibzard.com·high signal
The nibzard Agentic Handbook introduces the Lethal Trifecta: agent risk peaks at the intersection of (1) access to private/sensitive data, (2) exposure to untrusted content (web, user input, third-party tools), and (3) capability to exfiltrate externally. Mitigation requires removing at least one leg: no external egress, no direct secret access, strict input separation, or tool compartmentalization. The handbook pairs this with Action Trace Monitoring — triggering kill switches on unexpected tool use, diff size thresholds, access to forbidden files, or repeated test failure loops.