Rules-File Backdoor — Supply Chain Attack on AI Coding Assistant Configuration - ATR-2026-00512 (5dfc44ab-33d8-5a4d-a8a6-f65bd16cf400)
Detects attempts to inject malicious instructions into AI coding assistant configuration files (.cursorrules, CLAUDE.md, .github/copilot-instructions.md, .clinerules, .continuerc, .codeium/) that persist across sessions. MITRE ATLAS AML.CS0041 (Rules File Backdoor). Attackers modify these files so every subsequent AI coding session includes a hidden backdoor: injecting scripts, exfiltrating files, logging credentials, or adding malicious dependencies. Patterns cover: (1) rules-file path combined with exfiltration or script-injection verbs, (2) "when generating X always include