When my agent started returning incoherent responses on the morning of April 17, I was on a bus on a mobile hotspot. I had no way to tell whether it had been hijacked, prompt-injected, hit a framework bug, or just broken under its own weight.
Containment-first was the only correct move there — pull the bot offline, get to a trusted network, then diagnose. The first post in this series told that story. This post is about what I did once I was actually at a keyboard.
I did not guess. I walked HECE.
Hypothesize. Evidence signatures. Check. Eliminate.
Unglamorous, but for a first-time incident like this one it worked. This is the protocol, the actual commands I ran on my own agent, the two false leads it killed, and a checklist you can run on yours.
