Analysis
Testing AI Agent Resilience to Prompt Injection - 5 Layers
First reported · Discovered patronusec.com
Page published
Earliest dated coverage: 10 Sep 2026 · First observed: 20 Oct 2026 · Latest dated coverage: 10 Sep 2026
Coverage timeline
Single-source analysis — one report is available.
Why it matters
Whole-agent prompt-injection testing helps defenders identify delayed tool misuse, persistent memory poisoning, and exfiltration paths that isolated model probes can miss.
Patronusec explains why prompt-injection testing should assess an AI agent’s full execution loop, including content retrieval, tool calls, and persistent memory, rather than only model responses. The article recommends layered testing and judging outcomes by unauthorized actions and whether controls outside the model can stop them.