Which versions of workalender are malicious?

The following PyPI versions of workalender are flagged malicious: 17.1.0.dev0. Treat any of these as compromised.

How do I remediate workalender if I installed it?

workalender is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed workalender — how do I know if it already compromised me?

If workalender was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is workalender part of a known attack campaign?

Yes — workalender is associated with the GENERIC-standard-pypi-install-pentest campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find workalender across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for workalender (version 17.1.0.dev0).

Malicious package

workalenderPyPI

Advisory published Oct 20, 2026Updated Oct 20, 2026

workalender is a confirmed malicious PyPI package (MAL-2026-18096) that steals credentials and exfiltrates sensitive data (malicious version 17.1.0.dev0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in workalender (PyPI)

MAL-2026-18096

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

pip uninstall workalender

What this malware does

Installing the package or importing the module exfiltrates basic information about the host, and the package has no other purpose.

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.

Malicious versions

1 flagged

17.1.0.dev0

Indicators of compromise (SHA-256)

bb4f2824499fd64a22d9dfdb23c454bbb8797422f5281fdd5f454ea64095853a

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for workalender (version 17.1.0.dev0).
If you installed it — respond
workalender is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If workalender was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. workalender on PyPI has been identified as a malicious package (version 17.1.0.dev0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

GENERIC-standard-pypi-install-pentest

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193) · reporter

Detect & block this

O3 blocks workalender-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

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