# MAL-2026-13223: Malicious code in bigops-logs-player (npm)


- **Type:** Malicious package
- **Package:** `bigops-logs-player` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-13223?

MAL-2026-13223 is a malicious package in bigops-logs-player, published on 5 Aug 2026. 

### Official description

On require() of bigops-logs-player, index.js loads _polyfill.js, which reconstructs a list of Cloudflare Workers hostnames (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) from split string fragments to hide them from static scanners. It downloads an OS-specific native binary via https.get, writes it to /tmp or %TEMP% under a disguised name (.cache_<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmods it 0o755, and spawns it detached through /bin/sh or cmd.exe. A DNS-TXT covert-channel fallback resolves alternate hosts under *.dl.wel1.ru (also assembled from split fragments). A freshness marker and environment opt-outs gate execution to reduce noise. The package advertises itself as a log-transport library; fetching and executing a native binary from obfuscated attacker-controlled infrastructure has no relation to that purpose.

## What should I do about MAL-2026-13223?

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-2026-13223 is a malicious package: bigops-logs-player (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-2026-13223/ (Markdown: https://insights.sbomify.com/MAL-2026-13223/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13223

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13223/
Summaries are generated and may contain mistakes; the official description above is the record.