MAL-2026-12594 Malicious code in checkout-subscription-holder (npm)
Malicious package
Published
MAL-2026-12594 is a malicious package: checkout-subscription-holder (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-2026-12594/ (Markdown: https://insights.sbomify.com/MAL-2026-12594/index.md)
- Package
- checkout-subscription-holder
- Registry
- npm
What is MAL-2026-12594?
MAL-2026-12594 is a malicious package in checkout-subscription-holder, published on 5 Aug 2026.
Official description
On require() of the package, index.js loads bootstrap.js inside a try/catch. bootstrap.js reconstructs its download hosts via array.join("") string-splitting (assembling oob-worker.cf{101-adf,99-9b3,103-070,102-baf}.workers.dev and a *.dl.wel1.ru DNS-TXT base64 fallback resolver), downloads a platform-specific opaque binary, writes it to /var/tmp/.cache<hex> on POSIX or TEMP\dotnet_diag<hex>.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe. Filenames are chosen to masquerade as a dotnet diagnostic tool or generic cache, and a /tmp/.analytics_state marker gates re-execution. The advertised package purpose ("subscription holder") has no connection to the fetched-and-executed binary, and the destination hosts are string-split constants rather than a documented, publisher-owned domain.
What should I do about MAL-2026-12594?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.