# MAL-2026-17164: Malicious code in building-build (npm)


- **Type:** Malicious package
- **Package:** `building-build` (npm)
- **Published:** 24 Sep 2026
- **Also known as:** GHSA-2fq4-2r26-qr64

## What is MAL-2026-17164?

MAL-2026-17164 is a malicious package in building-build, published on 24 Sep 2026. 

### Official description

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.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-17164?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-17164 is a malicious package: building-build (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-17164/ (Markdown: https://insights.sbomify.com/MAL-2026-17164/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-17164

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-17164/
Summaries are generated and may contain mistakes; the official description above is the record.