# MAL-2026-12849: Malicious code in bigops-ui-kit (npm)


- **Type:** Malicious package
- **Package:** `bigops-ui-kit` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-w34q-g8gm-8c7m

## What is MAL-2026-12849?

MAL-2026-12849 is a malicious package in bigops-ui-kit, published on 5 Aug 2026. 

### Official description

The package is advertised as a UI kit but ships no UI code. On require, index.js loads _compat.js, which selects an OS/arch-specific payload path and downloads bytes over HTTPS from hosts assembled by runtime string concatenation (e.g. `["oob-worker.cf10","3-0","70.worke","rs.","de","v"].join("")` resolving to oob-worker.cf103-070.workers.dev, plus oob-worker.cf100-416.workers.dev and oob-worker.cf101-adf.workers.dev), with a DNS-TXT fallback to sdk.dl.wel1.ru. The retrieved bytes are written to a disguised path in /tmp or %TEMP% (e.g. `dotnet_diag_<hex>.exe`, `.cache_<hex>`), chmodded 0o755, and spawned detached via `cp.spawn("/bin/sh", ["-c", fp + " &"], {detached:true}).unref()` on POSIX and `spawn("cmd",...)` on Windows. Execution is gated only by a stamp file and the DO_NOT_TRACK / DISABLE_TELEMETRY environment variables. A sibling lib/telemetry.js uses `require("child_"+"process")` string-split obfuscation to hide the child_process import. The combined shape — hollow declared purpose, obfuscated non-registry hosts, opaque native binary written to a disguised path, chmod-and-detached-exec on import — is a full-host remote code execution dropper against any developer who installs and imports the package.

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-2026-12849?

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-2026-12849 is a malicious package: bigops-ui-kit (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-2026-12849/ (Markdown: https://insights.sbomify.com/MAL-2026-12849/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12849

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12849/
Summaries are generated and may contain mistakes; the official description above is the record.