TC-2025-0007 · NPM · MCP
[email protected]
First documented malicious MCP server in the wild. Version 1.0.16 injected a covert BCC to [email protected] on every outbound email sent by the agent.
Signed ledger verdict
TC-2025-0007
Known bad (exit 2)
npm:[email protected]
IOC & scope: npm:[email protected]. Verified by human review and signed into the CC-BY 4.0 OSV v1.6.0 feed.
Run live in Counter Workbench
Signed in /feed.json (.sig).
Deterministic capability profile and taxonomy mapping.
Every artifact in the threat.cafe ledger is profiled across eight execution vectors and mapped to the OWASP Top 10 for Agentic Applications (ASI01-ASI10) and Agentic Skills & Tools (AST01-AST10).
8-Vector Capability X-Ray (ABOM)
-
1. Filesystem
Sensitive paths touched:
None observed -
2. Environment
Variables harvested:
POSTMARK_SERVER_TOKEN -
3. Network
Outbound egress domains:
api.postmarkapp.com (covert BCC -> [email protected]) -
4. Subprocess
Process execution primitives:
None observed -
5. Lifecycle
Install / startup hooks:
None observed -
6. OAuth / MCP
Declared scopes:
email:send -
7. Obfuscation
Encoding / steganography:
None observed -
8. Provenance
Attestation status:
unpinned_npm_publish
Governance & detector mapping
- OWASP Agentic ASI (2026): ASI02 (Tool Misuse & Exploitation), ASI04 (Agentic Supply Chain Vulnerabilities)
- OWASP Agentic AST (2026): AST01 (Malicious MCP Servers), AST04 (Covert Channel Exfiltration)
- Deterministic rules matched:
RULE_08_DESC_BEHAVIOR_MISMATCH
Version scoping & related records
- TC-2026-0105 (npm:[email protected]): status
no_known_bad— Verified build of postmark-mcp prior to the 1.0.16 covert BCC injection. Sends email solely to caller-specifie
Local CLI verification
$ threat-cafe-hook check "npm:[email protected]" [threat.cafe] known_bad: npm:[email protected] (TC-2025-0007) Reason: First documented malicious MCP server in the wild. Version 1.0.16 injected a covert BCC to Source: https://thehackernews.com/2025/09/first-malicious-mcp-server-found.html (credited to Koi Security)
OSV v1.6.0 machine-readable record
Included in /feed.json under CC-BY 4.0 license and verified by /feed.json.sig.
{
"schema_version": "1.6.0",
"id": "TC-2025-0007",
"modified": "2025-09-26T09:00:00Z",
"published": "2025-09-26T09:00:00Z",
"summary": "First documented malicious MCP server in the wild. Version 1.0.16 injected a covert BCC to [email protected] on every outbound email sent by the agent.",
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "postmark-mcp"
},
"versions": [
"1.0.16"
]
}
],
"credits": [
{
"name": "Koi Security",
"type": "FINDER"
}
],
"references": [
{
"type": "ADVISORY",
"url": "https://thehackernews.com/2025/09/first-malicious-mcp-server-found.html"
},
{
"type": "WEB",
"url": "https://threat.cafe/incidents/tc-2025-0007/"
}
],
"database_specific": {
"target": "npm:[email protected]",
"kind": "mcp",
"verdict": "known_bad",
"ioc": "npm:[email protected]",
"artifact_sha256": "c73826f56331d2570e158c426f629025d825a9e380aff447214d9bb997dd904e",
"owasp_asi": [
"ASI02",
"ASI04"
],
"owasp_ast": [
"AST01",
"AST04"
],
"rules_matched": [
"RULE_08_DESC_BEHAVIOR_MISMATCH"
],
"abom": {
"fs_sensitive": [],
"env_harvest": [
"POSTMARK_SERVER_TOKEN"
],
"net_egress": [
"api.postmarkapp.com (covert BCC -> [email protected])"
],
"proc_exec": [],
"install_hooks": [],
"oauth_scopes": [
"email:send"
],
"obfuscation": [],
"provenance": "unpinned_npm_publish"
},
"license": "CC-BY-4.0",
"record_digest": "sha256:d768c698f30a40b7a80647d1404f1edf23c8b38ce31cf95892e82c20fb45aa55",
"release_signature_url": "https://threat.cafe/feed.json.sig"
}
}
Have additional IOCs or a maintainer remediation update for TC-2025-0007?
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