workalender

GHSA-w7r8-xc7m-3j8g

Malicious code in workalender (PyPI)

Details

**Severity:** Critical

**Affected versions:** `= 17.1.0.dev0`

## Source: kam193 (bb4f2824499fd64a22d9dfdb23c454bbb8797422f5281fdd5f454ea64095853a)
Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.


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Category: PROBABLY_PENTEST - Packages looking like typical pentest packages, but also anything that looks like testing, exploring pre-prepared kits, research & co, with clearly low-harm possibilities.


Campaign: GENERIC-standard-pypi-install-pentest


Reasons (based on the campaign):


 - The package contains code to exfiltrate basic data from the system, like IP or username. It has a limited risk.


 - The package overrides the install command in setup.py to execute malicious code during installation.

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Credit: [OpenSSF](https://github.com/ossf/malicious-packages) ([source](https://github.com/ossf/malicious-packages/blob/cb51fe43f9a76d25f225f2f5f7aca7e7dcf090a3/osv/malicious/pypi/workalender/MAL-2026-18096.json))

**References:**
- https://bad-packages.kam193.eu/pypi/package/workalender
- https://github.com/ossf/malicious-packages/blob/cb51fe43f9a76d25f225f2f5f7aca7e7dcf090a3/osv/malicious/pypi/workalender/MAL-2026-18096.json
- https://github.com/advisories/GHSA-w7r8-xc7m-3j8g

Compromised versions (1)

= 17.1.0.dev0

Any computer that installed or ran a compromised version should be considered fully compromised. Rotate every secret on that machine from a clean environment.