@yongot/canary-mcp-test

GHSA-469r-xxvx-62x3

Malicious code in @yongot/canary-mcp-test (npm)

Details

**Severity:** Critical

**Affected versions:** `= 3.0.0`

## Source: amazon-inspector (b93b70d19f6065f9757e39a5d7f799ca9cfff26e2c47b6e4c51012a104885578)
Package @yongot/[email protected] ships beacon.js which runs `execSync('id')`, reads `os.hostname()`, and issues an HTTPS GET to a hardcoded webhook.site collector (https://webhook.site/b76376f8-118e-44f1-a5ee-8a73f55b137b) with stage, host, and id_output query parameters. The package.json postinstall hook invokes `node beacon.js postinstall`, so the beacon fires automatically on `npm install`. index.js (the package main) also requires beacon.js twice at load time, so any consumer that imports the package re-triggers the same exfiltration of the installer's Unix uid/gid/groups and hostname to the third-party webhook collector.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/052f71eef3f234515289c1fcfc69fdca0f7048b3/osv/malicious/npm/@yongot/canary-mcp-test/MAL-2026-16062.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/052f71eef3f234515289c1fcfc69fdca0f7048b3/osv/malicious/npm/@yongot/canary-mcp-test/MAL-2026-16062.json
- https://www.npmjs.com/package/@yongot/canary-mcp-test/v/2.0.0
- https://www.npmjs.com/package/@yongot/canary-mcp-test/v/3.0.0
- https://www.npmjs.com/package/@yongot/canary-mcp-test/v/4.0.0
- https://github.com/advisories/GHSA-469r-xxvx-62x3

Compromised versions (1)

= 3.0.0

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.