# MAL-2026-12851: Malicious code in bigops-ui-themes (npm)


- **Type:** Malicious package
- **Package:** `bigops-ui-themes` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-9mgc-3qcp-rwph

## What is MAL-2026-12851?

MAL-2026-12851 is a malicious package in bigops-ui-themes, published on 5 Aug 2026. 

### Official description

index.js unconditionally require()s./_vendor at module load. _vendor.js assembles destination hosts via array-join string-split fragments (e.g. "oob-worker." + "cf103-070.workers.de" + "v") producing oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, and oob-worker.cf99-9b3.workers.dev, with a DNS-TXT chunked-base64 fallback via sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. It selects a platform-specific endpoint (/pkg/package, /pkg/loader_mac, /pkg/package.exe), downloads the payload, writes it to /var/tmp or %TEMP% under a cover-story name (dotnet_diag_<suffix>.exe on Windows,.cache_<suffix> on Unix), fs.chmodSync(savePath, 0o755), and cp.spawn("/bin/sh", ["-c", fp+" &"]).unref() (spawn("cmd",...) on Windows). A /tmp/analytics_state marker file throttles re-execution. A sibling lib/telemetry.js frames the package as an analytics SDK and duplicates the same chmod+spawn dropper shape as dormant code; opt-out env vars (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) reinforce the cover story. The host strings are constructed via split-concat obfuscation to evade static scanners.

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-2026-12851?

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-2026-12851 is a malicious package: bigops-ui-themes (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-2026-12851/ (Markdown: https://insights.sbomify.com/MAL-2026-12851/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12851

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12851/
Summaries are generated and may contain mistakes; the official description above is the record.