mainxPyPI
Advisory published Updated
mainx is a confirmed malicious PyPI package (MAL-2025-6540) that steals credentials and exfiltrates sensitive data (malicious versions 0.1, 0.4, 0.5…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in mainx (PyPI)
What this malware does
While described as educational package to simulate post-exploitation environment, the malware is active and once started, automatically attempts to exfiltrate sensitive data (credentials, cookies, etc.) and places a Discord implant. The remote target is hard coded in the code.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2025-06-mainx
Reasons (based on the campaign):
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obfuscation
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infostealer
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files-exfiltration
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exfiltration-credentials
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exfiltration-browser-data
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peristence-autorun
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The package contains code to detect if it is running in a sandbox environment.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for mainx (9 malicious versions).
If you installed it — respond
mainx 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 mainx 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)
- ReversingLabs · finder
Detect & block this
O3 blocks mainx-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.