# MAL-2026-12389: Malicious code in github-app-sts-action (npm)


- **Type:** Malicious package
- **Package:** `github-app-sts-action` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-wmg2-8x3r-rg73

## What is MAL-2026-12389?

MAL-2026-12389 is a malicious package in github-app-sts-action, published on 5 Aug 2026. 

### Official description

The package declares a preinstall lifecycle hook that runs index.js on `npm install`. index.js collects host identifiers and system files (os.hostname(), os.userInfo(), home directory, DNS servers, /etc/passwd, /etc/hosts, and package.json contents) and POSTs them via HTTPS to the hardcoded subdomain lncqub6t1loht8b887c8hvcjva13ptdi.oastify.com — a Burp Collaborator out-of-band interaction host used for reconnaissance. There is no advertised functional purpose in the package that would justify this data collection; the code path exists solely to transmit installer host and credential-adjacent file contents to an attacker-controlled endpoint.

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-2026-12389?

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-2026-12389 is a malicious package: github-app-sts-action (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-2026-12389/ (Markdown: https://insights.sbomify.com/MAL-2026-12389/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12389

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12389/
Summaries are generated and may contain mistakes; the official description above is the record.