helmet-fastapiPyPI
Advisory published Updated
helmet-fastapi is a confirmed malicious PyPI package (MAL-2025-191752) that steals credentials and exfiltrates sensitive data (malicious versions 1.2, 1.3, 1.3.1…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in helmet-fastapi (PyPI)
What this malware does
Package contains hidden code adding a backdoor - a WebSocket path handler which will execute commands sent by an attacker knowing the path. In addition, it adds a log handler to remove related access logs.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2025-04-helmet-fastapi
Reasons (based on the campaign):
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backdoor
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obfuscation
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for helmet-fastapi (5 malicious versions).
If you installed it — respond
helmet-fastapi 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 helmet-fastapi 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)
Detect & block this
O3 blocks helmet-fastapi-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.