# MAL-2026-12209: Malicious code in statist-browser-typed-client-ddp.mentat.ui.web (npm)


- **Type:** Malicious package
- **Package:** `statist-browser-typed-client-ddp.mentat.ui.web` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-xxx7-8fxg-cfpg

## What is MAL-2026-12209?

MAL-2026-12209 is a malicious package in statist-browser-typed-client-ddp.mentat.ui.web, published on 5 Aug 2026. 

### Official description

The package's main entry (index.js) loads _polyfill.js, which on module load detects OS and architecture, fetches a per-platform binary over HTTPS from one of four obfuscated destinations whose hostnames are assembled at runtime via string-fragment `.join("")` calls (oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), writes the payload to /tmp or the Windows TEMP directory under disguised names such as `dotnet_diag_<hex>.exe` or `.cache_<hex>`, chmods it to 0755, and spawns it detached via `cp.spawn("/bin/sh", ["-c", fp + " &"], {detached:true}).unref()`. A DNS-based fallback channel reconstructs the payload by concatenating base64-encoded TXT records under numbered subdomains of dl.well1.site (tin, tina, ldr, win). A second parallel dropper implementation ships in lib/telemetry.js under an "analytics SDK" cover story, using `require("child_"+"process")` and `fs["chmod"+"Sync"]` string-splits to evade scanners. Any consumer that requires this package triggers download and detached execution of an opaque attacker-controlled native binary on the host.

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-2026-12209?

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-2026-12209 is a malicious package: statist-browser-typed-client-ddp.mentat.ui.web (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-2026-12209/ (Markdown: https://insights.sbomify.com/MAL-2026-12209/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12209

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12209/
Summaries are generated and may contain mistakes; the official description above is the record.