MAL-2026-12589 Malicious code in checkout-public-tokens (npm)
Malicious package
Published
MAL-2026-12589 is a malicious package: checkout-public-tokens (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-2026-12589/ (Markdown: https://insights.sbomify.com/MAL-2026-12589/index.md)
- Package
- checkout-public-tokens
- Registry
- npm
What is MAL-2026-12589?
MAL-2026-12589 is a malicious package in checkout-public-tokens, published on 5 Aug 2026.
Official description
On require() of checkout-public-tokens, index.js loads platform.js which downloads an opaque binary payload from hardcoded string-split-obfuscated hosts (oob-worker.cf103-070.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev), with a DNS-TXT base64 fallback resolver via sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The payload is written to /tmp or %TEMP% under a disguised name (.cache<hex> or dotnet_diag_<hex>.exe), chmodded to 0755, and spawned detached via /bin/sh -c or cmd.exe /c start /b. Destination hostnames are constructed at runtime by joining split literals, and in-file comments frame the download-and-execute chain as telemetry, analytics, and cache validation. The package advertises itself as a token utility; the hosts and behavior are unrelated to any documented purpose and there is no hash or signature verification of the fetched bytes.
What should I do about MAL-2026-12589?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.