# Replicate a scary agent security claim with a harmless canary before you react

PaperChase agent use case (free feed entry), version 1.0. Source: [Chris Johnson (@ComputeGhost)](https://x.com/ComputeGhost/status/2115299194454028514), 2026-10-28.

## What they did

The original post claimed high hijack rates when an agent is launched in a folder that contains a planted instruction file. He replaced the payload with a canary (an instruction to write a marker file that does nothing), ran each agent in its default mode and in its sandboxed mode, 20 runs per cell, in fresh containers, and counted how often the canary appeared. It never did on the versions he tested.

## Worth knowing

The result is not that the attack is fake; it is that it did not reproduce on those versions and settings, and the original may have used other versions, folders or prompts. The method is the takeaway: a canary instead of a real payload, a matrix of agents and modes, enough runs per cell, fresh containers, and a report that names versions. It is a good habit before you change your setup because of one alarming post.

## Workflow template

```text
Apply this workflow to [your project]:
1. Write down the exact claim: which agent, version, setting and success rate.
2. Replace any harmful payload with a canary, such as creating an empty marker file.
3. Build a matrix of agents and modes and run each cell at least 20 times in fresh throwaway containers.
4. Count canary hits per cell and record versions and settings.
5. Report the result with its limits, including what you did not test.
Stop and ask me before anything irreversible: deploys, payments, sends or deletes.
```

## Steps

1. **Write down the exact claim: which agent, version, setting and success .** Write down the exact claim: which agent, version, setting and success rate.
2. **Replace any harmful payload with a canary, such as creating an empty m.** Replace any harmful payload with a canary, such as creating an empty marker file.
3. **Build a matrix of agents and modes and run each cell at least 20 times.** Build a matrix of agents and modes and run each cell at least 20 times in fresh throwaway containers.
4. **Count canary hits per cell and record versions and settings.** Count canary hits per cell and record versions and settings.
5. **Report the result with its limits, including what you did not test.** Report the result with its limits, including what you did not test.

## Credit

Workflow reported by Chris Johnson (@ComputeGhost): https://x.com/ComputeGhost/status/2115299194454028514
Related: https://forever.security/blog/hijacking-ai-agents-via-downloads-folder/

Summary and template written by PaperChaseWebb in our own words. Questions: mgmt@paperchasewebb.com