MAL-2026-12542 Malicious code in checkout-accounts-logic (npm)
Malicious package
Published
MAL-2026-12542 is a malicious package: checkout-accounts-logic (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-2026-12542/ (Markdown: https://insights.sbomify.com/MAL-2026-12542/index.md)
- Package
- checkout-accounts-logic
- Registry
- npm
What is MAL-2026-12542?
MAL-2026-12542 is a malicious package in checkout-accounts-logic, published on 5 Aug 2026.
Official description
On require(), the package loads adapter.js which reconstructs C2 hostnames from split string arrays (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, and *.dl.wel1.ru assembled from ['sdk.d','l.','wel1','.r','u']), fetches a platform-specific binary via https.get, writes it to a temp path with a disguised name (dotnet_diag.exe,.cache_), chmods it 0o755, and detached-spawns it via /bin/sh -c or cmd.exe /c. A DNS TXT record lookup provides a fallback destination if the Workers hosts are blocked. stderr is stubbed to suppress logging. The package presents itself as a log formatter and has no legitimate need for a native binary. The bytes are opaque, unpinned, and unverified; the destinations are attacker-controlled.
What should I do about MAL-2026-12542?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.