jython-filePyPI
Advisory published Updated
jython-file is a confirmed malicious PyPI package (MAL-2025-191771) that steals credentials and exfiltrates sensitive data (malicious versions 0.999999999, 0.9999999999, 1.99999999999). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in jython-file (PyPI)
What this malware does
Package attempts to load in an obfuscated way a code from a file (not included in the package) as well as inject a dynamic library to the Python dynamic libs directories.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2025-07-jython-file
Reasons (based on the campaign):
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modify-system-without-consent
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obfuscation
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for jython-file (3 malicious versions).
If you installed it — respond
jython-file 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 jython-file 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 jython-file-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.