Which versions of yuzo are malicious?

The following PyPI versions of yuzo are flagged malicious: 1.0.0, 1.0.1, 1.0.2, 1.4.3. Treat any of these as compromised.

How do I remediate yuzo if I installed it?

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

If yuzo 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 yuzo part of a known attack campaign?

Yes — yuzo is associated with the RLMA-2025-05231, 2025-09-suyo, RLUA-2026-00943 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 yuzo across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for yuzo (4 malicious versions).

Malicious package

yuzoPyPI

Advisory published Sep 19, 2025Updated Mar 19, 2026

yuzo is a confirmed malicious PyPI package (MAL-2025-48911) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1, 1.0.2…). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in yuzo (PyPI)

MAL-2025-48911

Immediate action

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

pip uninstall yuzo

What this malware does

Package contains an infostealer and is clearly prepared for using it. Different versions present different variations, newer are based on CStealer. The exfiltration target is a hardcoded discord webhook

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

Campaign: 2025-09-suyo

Reasons (based on the campaign):

infostealer
infostealer:cstealer
exfiltration-browser-data

Malicious versions

4 flagged

1.0.01.0.11.0.21.4.3

Indicators of compromise (SHA-256)

9aca61cad4edb45dc2317dc31bd953db265a08c9ce0668699777692b62339b71

8fe0df38f75f51506b166f64d9a76f47859f894943fccfb55ca0677979ef07b8

deb22bdfdecb739735dd50a5e0e2fe8329ee260b7236db8112629d7516d081d4

2551c1897302570c72b4c07f118a6704e69f1dc6f449f2d976c2fcdb59aa397e

5f2210c17eb33c165dda287e147cda18b1596c55fc61f806cc749c6661753131

Detection & response playbook

Credential / info stealer

Find it
Search your lockfiles and build artifacts for yuzo (4 malicious versions).
If you installed it — respond
yuzo 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 yuzo 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. yuzo on PyPI has been identified as a malicious package (versions 1.0.0, 1.0.1, 1.0.2, 1.4.3 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

RLMA-2025-052312025-09-suyoRLUA-2026-00943

References

bad-packages.kam193.eu

Credits

Kamil Mańkowski (kam193)
ReversingLabs · finder

Detect & block this

O3 blocks yuzo-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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