# MAL-2026-12740: Malicious code in devplatform-react-rest-client (npm)


- **Type:** Malicious package
- **Package:** `devplatform-react-rest-client` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-4j95-vr6c-r5xm

## What is MAL-2026-12740?

MAL-2026-12740 is a malicious package in devplatform-react-rest-client, published on 5 Aug 2026. 

### Official description

On require of this package, index.js loads _ext.js, which fetches a platform-specific binary from a rotating list of Cloudflare workers.dev hosts assembled at runtime via array.join to defeat static string scanning (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), with a DNS-TXT chunked fallback channel via *.dl.wel1.ru (sdk, ext, pkg, net). The fetched binary is written to /tmp or %TEMP% under a cover-story name impersonating.NET diagnostics tooling (dotnet_diag_<hex>.exe on Windows,.cache_<hex> on POSIX), chmod 0755 on POSIX, and spawned detached via /bin/sh -c or cmd.exe. Any consumer that requires the package on install/import receives arbitrary attacker-controlled code execution 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-2026-12740?

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-2026-12740 is a malicious package: devplatform-react-rest-client (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-2026-12740/ (Markdown: https://insights.sbomify.com/MAL-2026-12740/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12740

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12740/
Summaries are generated and may contain mistakes; the official description above is the record.