puan4PyPI
Advisory published Updated
puan4 is a confirmed malicious PyPI package (MAL-2026-3244) that steals credentials and exfiltrates sensitive data (malicious version 1.0.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in puan4 (PyPI)
What this malware does
During import, package automatically starts a connection to a C2 server, exfiltrates information about the host and data like sensitive files and browsers' data.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-05-puan3
Reasons (based on the campaign):
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exfiltration-generic
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exfiltration-browser-data
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The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.
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rat
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exfiltration-credentials
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for puan4 (version 1.0.3).
If you installed it — respond
puan4 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 puan4 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
Campaign
References
Credits
- Kamil Mańkowski (kam193) · reporter
Detect & block this
O3 blocks puan4-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.