Which versions of flexssl are malicious?

The following PyPI versions of flexssl are flagged malicious: 2.0.0. Treat any of these as compromised.

How do I remediate flexssl if I installed it?

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

If flexssl 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 flexssl part of a known attack campaign?

Yes — flexssl 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 flexssl across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for flexssl (version 2.0.0).

Malicious package

flexsslPyPI

Advisory published Jul 26, 2024Updated Dec 12, 2025

flexssl is a confirmed malicious PyPI package (MAL-2024-12274) that steals credentials and exfiltrates sensitive data (malicious version 2.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in flexssl (PyPI)

MAL-2024-12274

Immediate action

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

pip uninstall flexssl

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

2.0.0

Indicators of compromise (SHA-256)

766695863729f53855514240c990d1cb9bcb42ab317cb3c1d49aad398f727ea3

03236867334bb1faf1e018f54b89046a0edf300be0152c00bf921dadaee600b0

8d7f8fa3d57d117b00f8726a3e941261662b602b3ce1ced55c9bd238a8eb54a2

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for flexssl (version 2.0.0).
If you installed it — respond
flexssl 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 flexssl 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. flexssl on PyPI has been identified as a malicious package (version 2.0.0 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)

Detect & block this

O3 blocks flexssl-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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