Which versions of pyfernet are malicious?

The following PyPI versions of pyfernet are flagged malicious: 0.0.1. Treat any of these as compromised.

How do I remediate pyfernet if I installed it?

pyfernet 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 pyfernet — how do I know if it already compromised me?

If pyfernet 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 pyfernet part of a known attack campaign?

Yes — pyfernet is associated with the RLMA-2025-03020, 2025-05-fernets, RLUA-2026-00630 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 pyfernet across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for pyfernet (version 0.0.1).

Malicious package

pyfernetPyPI

Advisory published May 27, 2025Updated Mar 19, 2026

pyfernet is a confirmed malicious PyPI package (MAL-2025-5123) that steals credentials and exfiltrates sensitive data (malicious version 0.0.1). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in pyfernet (PyPI)

MAL-2025-5123

Immediate action

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

pip uninstall pyfernet

What this malware does

If imported, the module starts a multi-stage infostealer, exfiltrating browser data as well as crypto wallets, and also attempts to monitor clipboard looking for crypto wallets addresses

Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2025-05-fernets

Reasons (based on the campaign):

infostealer
clipboard-stealing
exfiltration-generic
obfuscation
exfiltration-browser-data
exfiltration-crypto
typosquatting

Malicious versions

1 flagged

0.0.1

Indicators of compromise (SHA-256)

ed80ef98612eb3aaad949163f4f0cc751265b3940a964d57baf1153a585d14cb

fdff1f19e5f1ab997df824814e20a0e45bd067a964d72433e069ea9d343d0cf1

5a2f90c0e3c6e46456cd3e319aaaf4a7b53475a554a997a964fdda898e85fcd0

0980354b90f27172271c592fe956b26f0da8bc72c831d8992ca262c4dda1edc5

c395211e960cd02a5539b696480a5c6ea8687457f14c0fdaa34e33a51c9a01e7

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for pyfernet (version 0.0.1).
If you installed it — respond
pyfernet 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 pyfernet 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. pyfernet on PyPI has been identified as a malicious package (version 0.0.1 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-030202025-05-fernetsRLUA-2026-00630

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193)
ReversingLabs · finder

Detect & block this

O3 blocks pyfernet-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

All malware advisories How O3 detects malware Vulnerability database