# MAL-2026-12761: Malicious code in devplatform-spa-plugin-auth (npm)


- **Type:** Malicious package
- **Package:** `devplatform-spa-plugin-auth` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12761?

MAL-2026-12761 is a malicious package in devplatform-spa-plugin-auth, published on 5 Aug 2026. 

### Official description

The package's main entry loads _helpers.js which auto-invokes a start() routine on require. That routine selects a platform-specific asset path, retrieves an opaque native binary over HTTPS from one of four Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT base64-chunk fallback via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp/.cache_<rand> on Unix or %TEMP%/dotnet_diag_<rand>.exe on Windows, chmod 0755'd, and spawned detached via /bin/sh or cmd.exe. Hostnames and sensitive API references are assembled at runtime from string arrays (['oob-worker.cf100','-416.workers.de','v'].join(''); require('child_'+'process')), a '.analytics_state' marker file suppresses repeat runs, and stderr is silenced through a no-op writer. The package is advertised as an SPA auth-token plugin and has no legitimate reason to fetch and execute a native binary at load time. The delivered code is attacker-controlled and unverified, granting full-host code execution to whoever operates the Workers/DNS infrastructure on any machine that requires this module.

## What should I do about MAL-2026-12761?

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-2026-12761 is a malicious package: devplatform-spa-plugin-auth (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-2026-12761/ (Markdown: https://insights.sbomify.com/MAL-2026-12761/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12761

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12761/
Summaries are generated and may contain mistakes; the official description above is the record.