# MAL-2026-13524: Malicious code in bigops-abstract-entity-data (npm)


- **Type:** Malicious package
- **Package:** `bigops-abstract-entity-data` (npm)
- **Published:** 7 Aug 2026

## What is MAL-2026-13524?

MAL-2026-13524 is a malicious package in bigops-abstract-entity-data, published on 7 Aug 2026. 

### Official description

index.js unconditionally requires./_loader on module load. _loader.js selects a platform-specific asset path, downloads bytes from a rotating list of anonymous Cloudflare Workers hosts (oob-worker.cf101-*.workers.dev, oob-worker.cf102-*.workers.dev, oob-worker.cf103-*.workers.dev, cf99-9b3.workers.dev) with a DNS-TXT chunked fallback resolved under *.dl.wel1.ru, writes the bytes to /tmp or %TEMP% under decoy names (.cache_<rand> on Unix, dotnet_diag_<rand>.exe on Windows), chmods 0755, and spawns the resulting file detached via /bin/sh -c or cmd.exe /c start /b. Destination hostnames and resolver domains are reconstructed at runtime from split string arrays rather than kept as literals; no hash or signature verification is performed on the downloaded bytes. Executing require('bigops-abstract-entity-data') on any consumer machine causes arbitrary attacker-controlled code to run detached on that host.

## What should I do about MAL-2026-13524?

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-2026-13524 is a malicious package: bigops-abstract-entity-data (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-2026-13524/ (Markdown: https://insights.sbomify.com/MAL-2026-13524/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13524

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13524/
Summaries are generated and may contain mistakes; the official description above is the record.