{
 "id": "AIR-2026-0346",
 "slug": "postmark-mcp-server-package-hijacked-for-email-exfiltration",
 "title": "Postmark MCP Server Package Hijacked for Email Exfiltration",
 "summary": "Threat actors performed a malicious rugpull update on a popular npm package for an MCP server. The compromised server successfully exfiltrated user emails through AI agents.",
 "type": "attack_on_ai",
 "categories": [
  "supply_chain",
  "agent_hijack",
  "data_leak"
 ],
 "severity": 3,
 "targets": [
  "framework_or_tooling"
 ],
 "products": [
  "Postmark MCP"
 ],
 "incident_date": "2025-09",
 "incident_date_precision": "month",
 "first_reported": "2026-03-31",
 "sources": [
  {
   "url": "https://atlas.mitre.org/studies/AML.CS0053",
   "publisher": "MITRE ATLAS",
   "title": "Poisoned Postmark MCP Server Email Exfiltration",
   "published_at": "2026-03-31"
  },
  {
   "url": "https://koi.ai/blog/postmark-mcp-npm-malicious-backdoor-email-theft",
   "publisher": "koi.ai",
   "title": "First Malicious MCP in the Wild: The Postmark Backdoor That's Stealing Your Emails",
   "published_at": "2026-03-31"
  }
 ],
 "source_count": 2,
 "confidence": 0.95,
 "status": "published",
 "origin": "seed_atlas",
 "tags": [
  "npm",
  "supply-chain",
  "mcp",
  "data-exfiltration"
 ],
 "created_at": "2026-10-18T06:55:08.239Z",
 "updated_at": "2026-10-18T06:55:08.239Z"
}