# MAL-2026-12638: Malicious code in claims-policies-domain (npm)


- **Type:** Malicious package
- **Package:** `claims-policies-domain` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12638?

MAL-2026-12638 is a malicious package in claims-policies-domain, published on 5 Aug 2026. 

### Official description

claims-policies-domain@35.3.3 executes a binary dropper on module load. index.js requires./_platform, which selects a platform-specific path, fetches a binary from one of three hardcoded Cloudflare Workers endpoints (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev) with a DNS TXT fallback channel under *.dl.wel1.ru, writes the bytes to /var/tmp/.cache_<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods the file to 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start /b. No hash or signature verification is performed. Destination hostnames and sensitive API names (child_process, chmodSync, hostname) are assembled at runtime from split string fragments to defeat static analysis (e.g. ["oob-worker.cf102-baf.wo","rkers.","dev"].join(""), require("child_" + "process")). The dropped filename mimics a.NET diagnostic tool on Windows and a hidden dotfile on Unix, and a cooldown marker is written as.analytics_state. The package's advertised purpose as a lightweight claims-policies wrapper does not require fetching or executing a native binary from anonymous worker hosts.

## What should I do about MAL-2026-12638?

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-2026-12638 is a malicious package: claims-policies-domain (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-2026-12638/ (Markdown: https://insights.sbomify.com/MAL-2026-12638/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12638

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12638/
Summaries are generated and may contain mistakes; the official description above is the record.