denomenallibPyPI
Advisory published Updated
denomenallib is a confirmed malicious PyPI package (MAL-2025-191716) that steals credentials and exfiltrates sensitive data (malicious version 2.7.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in denomenallib (PyPI)
What this malware does
Package is prepared to exfiltrate sensitive files. Different packages use different places for the malicious code: it runs during importing the module, is placed in a native binary, or in the setup.py script
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2025-08-xenlib
Reasons (based on the campaign):
- files-exfiltration
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for denomenallib (version 2.7.0).
If you installed it — respond
denomenallib 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 denomenallib 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
Campaign
References
Credits
- Kamil Mańkowski (kam193)
Detect & block this
O3 blocks denomenallib-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.