MAL-2026-16407 Malicious code in poly-check-b (PyPI)
Malicious package
Published
MAL-2026-16407 is a malicious package: poly-check-b (PyPI). 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-2026-16407/ (Markdown: https://insights.sbomify.com/MAL-2026-16407/index.md)
- Package
- poly-check-b
- Registry
- PyPI
What is MAL-2026-16407?
MAL-2026-16407 is a malicious package in poly-check-b, published on 22 Sep 2026.
Official description
During installation, the package attempts to silently execute code. In analyzed versions, the payload file was missing.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-09-snap-queue
Reasons (based on the campaign):
- The package overrides the install command in setup.py to execute malicious code during installation.
What should I do about MAL-2026-16407?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.