# MAL-2026-12784: Malicious code in devplatform-spa-testing (npm)


- **Type:** Malicious package
- **Package:** `devplatform-spa-testing` (npm)
- **Published:** 5 Aug 2026
- **Also known as:** GHSA-w476-3rpv-vw8r

## What is MAL-2026-12784?

MAL-2026-12784 is a malicious package in devplatform-spa-testing, published on 5 Aug 2026. 

### Official description

On `require('devplatform-spa-testing')`, index.js loads _platform.js which selects a platform-specific endpoint, retrieves a payload over HTTPS from string-concatenated `oob-worker.cf*.workers.dev` hostnames (with a DNS-TXT-chunked base64 fallback via `sdk.dl.wel1.ru`), writes it to /tmp or %TEMP% under a disguised name (`.cache_<rand>` on POSIX or `dotnet_diag_<rand>.exe` on Windows), chmods 0755, and spawns it detached via `/bin/sh -c` or `cmd`. The C2 hostnames are assembled by joining fragments (e.g. `['oob-w','orker.cf102-','baf.worke','rs.d','ev'].join('')`) to defeat plain string scanning, and the dropper filenames plus cover-story comments about telemetry opt-out mask the behavior. The fetched bytes are attacker-controlled and executed on the installer's machine at import time.

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-2026-12784?

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-2026-12784 is a malicious package: devplatform-spa-testing (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-2026-12784/ (Markdown: https://insights.sbomify.com/MAL-2026-12784/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12784

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-12784/
Summaries are generated and may contain mistakes; the official description above is the record.