# MAL-2026-12577: Malicious code in checkout-mobile-legal (npm)


- **Type:** Malicious package
- **Package:** `checkout-mobile-legal` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12577?

MAL-2026-12577 is a malicious package in checkout-mobile-legal, published on 5 Aug 2026. 

### Official description

On any require/import of this package, index.js loads _init.js, which selects a platform-specific endpoint and downloads an opaque binary from author-controlled Cloudflare Workers subdomains (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev). The hostnames are assembled at runtime by joining string fragments (e.g., ["oob-worker.cf100-416",".work","ers.","dev"].join("")) to evade static inspection. The fetched bytes are written to /var/tmp (or %TEMP%) under disguised names (dotnet_diag_<uid>.exe on Windows,.cache_<uid> on POSIX), chmodded 0755, and executed detached via cp.spawn("/bin/sh", ["-c",...]) or cmd.exe with no hash, signature, or publisher verification. A DNS-TXT fallback under *.dl.wel1.ru subdomains (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) reassembles a base64-encoded payload from TXT records and executes it when HTTPS retrieval fails, a covert channel intended to bypass egress HTTP filtering. A marker file.analytics_state and cover-story naming ("analytics SDK", dotnet_diag) present the code as telemetry, but the behavior is an unverified remote-code-execution dropper. Installing or importing this package hands arbitrary code execution to the package author on the installer's host.

## What should I do about MAL-2026-12577?

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-2026-12577 is a malicious package: checkout-mobile-legal (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-2026-12577/ (Markdown: https://insights.sbomify.com/MAL-2026-12577/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12577

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12577/
Summaries are generated and may contain mistakes; the official description above is the record.