Rules File Backdoor: Supply Chain Attack on AI Coding Assistants

# Rules File Backdoor: Supply Chain Attack on AI Coding Assistants

https://gcdradar.vercel.app/incidents/rules-file-backdoor-supply-chain-attack-on-ai-coding-assista · AIR-2025-0065 · closed 2025-11-21

- Lane: Research
- Severity: 1 (Research / proof of concept)
- Fix status: Fix status unknown
- First reported: 2025-11-07 (happened 2025-03-18)
- AI role: Attack on AI
- Products: Cursor, GitHub Copilot

## Summary

Researchers demonstrated a supply chain attack where malicious instructions hidden in rules files using Unicode characters manipulated AI coding assistants. The attack tricked tools like Cursor and GitHub Copilot into generating vulnerable code.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2025-11-07: New Vulnerability in GitHub Copilot and Cursor: How Hackers Can Weaponize Code Agents (https://pillar.security/blog/new-vulnerability-in-github-copilot-and-cursor-how-hackers-can-weaponize-code-agents)
- 2025-11-07: Rules File Backdoor: Supply Chain Attack on AI Coding Assistants (https://atlas.mitre.org/studies/AML.CS0041)

## Sources

- 2025-11-07 MITRE ATLAS: Rules File Backdoor: Supply Chain Attack on AI Coding Assistants https://atlas.mitre.org/studies/AML.CS0041
- 2025-11-07 Pillar Security: New Vulnerability in GitHub Copilot and Cursor: How Hackers Can Weaponize Code Agents https://pillar.security/blog/new-vulnerability-in-github-copilot-and-cursor-how-hackers-can-weaponize-code-agents

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.