Which versions of pywool are malicious?

The following PyPI versions of pywool are flagged malicious: 1.0.0, 1.0.2. Treat any of these as compromised.

How do I remediate pywool if I installed it?

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

If pywool 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 pywool part of a known attack campaign?

Yes — pywool is associated with the RLMA-2024-04640 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 pywool across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for pywool (2 malicious versions).

Malicious package

pywoolPyPI

pywool is a confirmed malicious PyPI package (MAL-2023-8591) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.2). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in pywool (PyPI)

MAL-2023-8591

Immediate action

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

pip uninstall pywool

What this malware does

Malicious packages campaign targeting developers, payload is hidden using Steganography, exfiltrate host information

Malicious versions

2 flagged

1.0.01.0.2

Indicators of compromise (SHA-256)

1ba602a97accda8e614fcf38d1af1cb7f1878bf2bd450b21f1be16a4c260123a

eff579325bff64990fe7221b3226977dcd5c42c3b41731a8502f579553d815ff

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for pywool (2 malicious versions).
If you installed it — respond
pywool 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 pywool 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. pywool on PyPI has been identified as a malicious package (versions 1.0.0, 1.0.2 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2024-04640

References

Credits

Checkmarx · finder
ReversingLabs · finder

Detect & block this

O3 blocks pywool-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