# MAL-2026-13502: Malicious code in devplatform-react-mcp (npm)


- **Type:** Malicious package
- **Package:** `devplatform-react-mcp` (npm)
- **Published:** 7 Aug 2026

## What is MAL-2026-13502?

MAL-2026-13502 is a malicious package in devplatform-react-mcp, published on 7 Aug 2026. 

### Official description

devplatform-react-mcp@35.5.6 is a dropper disguised as a React MCP SDK. On require(), index.js loads _helpers.js which assembles three Cloudflare Workers hostnames (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev) from small string fragments joined at runtime, downloads a platform-specific binary via https.get, writes it to /tmp/.cache_<hex> or %TEMP%\dotnet_diag_<hex>.exe, chmods it 0755, and spawns it detached via /bin/sh -c or cmd /c start. A DNS-TXT fallback resolves further payload sources under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. A second dropper pipeline in lib/telemetry.js repeats the same primitives (base64 chunk assembly, fs["chmod"+"Sync"], cp.spawn("/bin/sh",["-c", filePath+" &"])) behind an 'analytics SDK' cover story. Identifier strings such as child_process and chmodSync are concatenated at runtime to evade static analysis. There is no native-build purpose; the package is a stub SDK whose only observable behavior on load is fetching and executing an opaque attacker-controlled binary on the installer's host.

## What should I do about MAL-2026-13502?

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-2026-13502 is a malicious package: devplatform-react-mcp (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-2026-13502/ (Markdown: https://insights.sbomify.com/MAL-2026-13502/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13502

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-13502/
Summaries are generated and may contain mistakes; the official description above is the record.