fetchium PyPI malware: covert Windows loader with MSI dropper and Run-key persistence
Severity: critical · Patch status: no-fix-needed · Since 2026-11-13
The PyPI package fetchium (versions 1.0.0 and 1.0.1), advertised as web/utility helpers (greet/clamp), ships a covert loader that runs on first import. init.py silently invokes loader.run() in a bare try/except; loader.py contains ~1.9 MB of base64+zlib-encoded payload chunks plus a Windows dropper that silently installs an MSI masquerading as MicrosoftEdgeUpdate.msi via msiexec/WMI. Embedded config evades sandboxes, VMs, and analysis tools and adds HKCU Run-key persistence (Microsoft\CoreRuntime). Flagged by Amazon Inspector and OpenSSF/kam193 as malicious (CWE-506), with VirusTotal and tria.ge samples. No patched versions exist; the package should be treated as fully malicious.
What to do
- Immediately remove fetchium from all environments and dependency lockfiles
- Hunt on Windows hosts for HKCU\Software\Microsoft\Windows\CurrentVersion\Run subkey Microsoft\CoreRuntime and MicrosoftEdgeUpdate.msi artifacts
- Reimage or rebuild any Windows machine where the package was imported
- Block the package name and associated hashes in artifact registries and proxies
- Audit for signs of follow-on infostealer activity and rotate credentials from affected hosts
Sources
All live incidents on Threat Watch
