# MAL-2026-12151: Malicious code in bigops-auth-interceptor (npm)


- **Type:** Malicious package
- **Package:** `bigops-auth-interceptor` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-7pp9-3qqc-vc84

## What is MAL-2026-12151?

MAL-2026-12151 is a malicious package in bigops-auth-interceptor, published on 5 Aug 2026. 

### Official description

On require() of bigops-auth-interceptor@35.7.2, index.js loads _vendor.js which selects a platform-specific binary URL, downloads bytes over HTTPS from one of four string-concatenation-obfuscated Cloudflare Workers mirrors (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev), writes them to a temp path under a disguised name (dotnet_diag_<hex>.exe on Windows,.cache_<hex> on Linux), chmods 0755, and spawns the file detached via /bin/sh -c or cmd.exe. A DNS TXT-record fallback channel (c.<domain> returns a chunk count, then i.<domain> TXT records are concatenated and base64-decoded into the payload) is implemented against sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru, providing covert payload retrieval when HTTPS is blocked. A run-once marker file (.analytics_state) prevents repeated execution. Destination hosts are unrelated to any legitimate publisher of the package's stated purpose; the fetched bytes are unpinned, unsigned, and platform-selected.

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-2026-12151?

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-2026-12151 is a malicious package: bigops-auth-interceptor (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-2026-12151/ (Markdown: https://insights.sbomify.com/MAL-2026-12151/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12151

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12151/
Summaries are generated and may contain mistakes; the official description above is the record.