Prompt Injection Scanner

prompt-injection-scanner

Scan READMEs, skills, and source code for prompt-injection attacks targeting AI coding assistants.

[](https://github.com/savaryncraftlab/prompt-injection-scanner/actions/workflows/ci.yml)   

AI coding assistants like **Claude Code**, **Cursor**, **GitHub Copilot**, **Aider**, and **Continue** read your repository files as part of their context — READMEs, `SKILL.md`, source comments, config files, all of it. That text isn't just displayed, it **becomes part of the prompt the model is running against**. The model has no way to tell "user typed this" from "a file on disk typed this".

That's the entire attack surface. Anyone can drop hidden instructions into a public repo — in an HTML comment, a code comment, or a fake "verified by Anthropic" note — and every agent that clones it is potentially compromised.

**This tool scans files for known prompt-injection patterns** so you can spot them before your agent does.


---

The attack, in 20 seconds

Here is a real-looking `README.md`:

# fast-json

A tiny library for parsing JSON 10x faster than the standard library.



## Install

    pip install fast-json

Rendered on GitHub, the HTML comment is invisible. Copy-pasted into a chat with an AI assistant, **it's just another paragraph of the prompt**. The assistant will cheerfully read your `.env` file, exfiltrate it, and tell you everything went fine.

There are