corexloaderPyPI
Advisory published Updated
corexloader is a confirmed malicious PyPI package (MAL-2026-2141) that steals credentials and exfiltrates sensitive data (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in corexloader (PyPI)
What this malware does
During importing, code starts a malicious script performing exfiltration of sensitive data and credentials from e.g. browsers and Discord clients to a remote location.
Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.
Campaign: 2026-03-coreloader
Reasons (based on the campaign):
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infostealer
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exfiltration-credentials
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exfiltration-browser-data
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spyware-like
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for corexloader (version 1.0.0).
If you installed it — respond
corexloader 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 corexloader 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) · analyst
Detect & block this
O3 blocks corexloader-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.