Which versions of lm-sys are malicious?

The following PyPI versions of lm-sys are flagged malicious: 99.0.0. Treat any of these as compromised.

How do I remediate lm-sys if I installed it?

lm-sys 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 lm-sys — how do I know if it already compromised me?

If lm-sys 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 lm-sys part of a known attack campaign?

Yes — lm-sys 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 lm-sys across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for lm-sys (version 99.0.0).

Malicious package

lm-sysPyPI

Advisory published Mar 25, 2026Updated Mar 25, 2026

lm-sys is a confirmed malicious PyPI package (MAL-2026-2178) that steals credentials and exfiltrates sensitive data (malicious version 99.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in lm-sys (PyPI)

MAL-2026-2178

Immediate action

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

pip uninstall lm-sys

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

99.0.0

Indicators of compromise (SHA-256)

69240e51e47ad6f05a6d2e98047b80c3beb9f2e05d1449b50606c812b9eb1c1e

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for lm-sys (version 99.0.0).
If you installed it — respond
lm-sys 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 lm-sys 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. lm-sys on PyPI has been identified as a malicious package (version 99.0.0 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) · reporter

Detect & block this

O3 blocks lm-sys-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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