building-build

GHSA-v37c-88px-mm6h

Malicious code in building-build (npm)

Details

**Severity:** Critical

**Affected versions:** `= 1.0.0`

## Source: amazon-inspector (4618f06d0398ff90ef90003464e79f23609a160f4d1606f60cf797fb73fa6dcb)
The package's sole content is index.js, which on load schedules a timer that fetches a hardcoded list of privileged same-origin paths (/admin, /dashboard, /flag, /api/flag, /secret, /admin/flag) and POSTs each response body to /addPost as JSON of the form {content: path + '::' + body}. When bundled into a web application, this abuses the ambient session of whichever authenticated user loads the bundle to read privileged routes and relay the contents to the site's posting endpoint. package.json has empty description, author, and keywords, no exports, and the name 'building-build' bears no relation to the shipped behavior — the package has no library surface and exists only to deliver this payload.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/fbd69de639befa276507689652dc04f12c5ef5cb/osv/malicious/npm/building-build/MAL-2026-17164.json))

**References:**
- https://github.com/ossf/malicious-packages/blob/fbd69de639befa276507689652dc04f12c5ef5cb/osv/malicious/npm/building-build/MAL-2026-17164.json
- https://www.npmjs.com/package/building-build/v/1.0.0
- https://github.com/advisories/GHSA-v37c-88px-mm6h

Compromised versions (1)

= 1.0.0

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