{
 "public_id": "AIR-2025-0015",
 "incident_id": "2025-03-cursor-copilot-rules-file-backdoor",
 "date_disclosed": "2025-03-18",
 "date_occurred": null,
 "title": "Rules File Backdoor: invisible-Unicode supply chain attack on Cursor and GitHub Copilot rules files",
 "class": "responsible_disclosure",
 "attack_surface": "coding_agent",
 "initial_vector": "poisoned_configuration_file",
 "agent_capability_abused": [
  "config_ingestion",
  "code_generation",
  "instruction_following_from_repo_config",
  "rules_file_ingestion"
 ],
 "target_product": "Cursor, GitHub Copilot",
 "target_vendor": "Anysphere, GitHub/Microsoft",
 "autonomy_level": "copilot_with_approval",
 "impact_realized": false,
 "impact_type": [
  "supply_chain_compromise",
  "backdoored_code",
  "malicious_code_generation",
  "backdoor_insertion",
  "credential_leakage",
  "supply_chain_backdoor",
  "credential_leak_in_generated_code"
 ],
 "blast_radius": "any repo or template that ships a poisoned rules file, plus downstream forks",
 "cve": [],
 "taxonomy": {
  "owasp_asi": [
   "ASI01",
   "ASI04"
  ],
  "mitre_atlas": [
   "AML.CS0041",
   "AML.T0051.001"
  ],
  "labels": [
   "invisible_unicode",
   "rules_file",
   "ai_supply_chain",
   "persistence",
   "hidden_unicode",
   "zero_width_characters",
   "bidi_markers",
   "config_poisoning",
   "supply_chain",
   "invisible_to_code_review"
  ]
 },
 "defense_present": "human code review",
 "defense_bypassed": true,
 "fix_shipped": "GitHub shipped a hidden-Unicode warning (May 2025); Cursor classified it as user responsibility",
 "primary_sources": [
  "https://www.pillar.security/blog/new-vulnerability-in-github-copilot-and-cursor-how-hackers-can-weaponize-code-agents",
  "https://raw.githubusercontent.com/mitre-atlas/atlas-data/main/dist/v6/ATLAS-2026.07.yaml"
 ],
 "verified_quote": "This technique enables hackers to silently compromise AI-generated code by injecting hidden malicious instructions into seemingly innocent configuration files used by Cursor and GitHub Copilot",
 "confidence": "high",
 "notes": "Pillar Security. Vendors disagreed on ownership: Cursor declined to treat it as a product vulnerability. | Class set to `responsible_disclosure` by hand because the source records disagreed; the override reason is kept in the curation log. Also reported under the titles: 'Rules File Backdoor: invisible Unicode instructions in AI coding-assistant config files'; 'Rules File Backdoor: invisible Unicode instructions in AI coding-assistant rules files poison generated code'.",
 "risk_category": "security_fraud",
 "risk_secondary": [],
 "risk_subcategory": "Insecure Code Generation",
 "risk_sub_secondary": [
  "Prompt Injection",
  "Supply Chain Compromise",
  "Persistence & Covert C2"
 ],
 "ai_entity": "generative",
 "agency": "agent_acted",
 "agency_debatable": true,
 "agency_reason": "the coding agent wrote backdoored code into the repository",
 "vector_family": "other",
 "vector_detail": "poisoned_configuration_file",
 "guardrail_kind": [
  "unknown"
 ],
 "guardrail_outcome": "silent",
 "xrefs": {
  "aiid": [],
  "atlas": [
   "AML.CS0041",
   "AML.T0051.001"
  ],
  "cve": [],
  "ghsa": []
 },
 "primary_asi": "ASI01",
 "agent_framework": "unknown",
 "model_provider": "microsoft",
 "model_name": "",
 "detection_mechanism": "external_researcher",
 "tool_access": "unknown",
 "financial_loss_band": "unknown",
 "eai_category": "hallucination",
 "eai_domain": "agent_output_quality",
 "eai_secondary": [
  "credential_theft",
  "supply_chain_vulnerabilities"
 ],
 "eai_reason": "subcategory: Insecure Code Generation",
 "asi_curated": [
  "ASI01",
  "ASI04"
 ],
 "asi_scope": "in_scope",
 "asi_provenance": "curated",
 "asi_reason": "curated: ASI01,ASI04",
 "submitted_by": "EAI Internal"
}