MAL-2026-4166 Malicious code in tarpackage (PyPI)
Malicious package
Published
MAL-2026-4166 is a malicious package: tarpackage (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-2026-4166/ (Markdown: https://insights.sbomify.com/MAL-2026-4166/index.md)
- Package
- tarpackage
- Registry
- PyPI
What is MAL-2026-4166?
MAL-2026-4166 is a malicious package in tarpackage, published on 19 May 2026.
Official description
The package exfiltrates env variables during installation
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-05-tarpackage
Reasons (based on the campaign):
The package overrides the install command in setup.py to execute malicious code during installation.
exfiltration-env-variables
What should I do about MAL-2026-4166?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.