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OpenAdvisories
Malicious MAL-2026-18102

semveer

PyPI package · versions 1.0.0

Reported Oct 20, 2026 · Updated Oct 22, 2026

If this package is installed

Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.

Details

Source: amazon-inspector (d86237b957fd063a0e1fcf250a510b2fb9566ab48652e56fe787d2e1a02e351a)
The sdist for 'semveer' ships an inert module (semveer/__init__.py contains only a __version__ stub) and places all runtime behavior inside setup.py's install hook. On pip install, setup.py calls urllib.request.urlretrieve against https://c2-worker.crawlnet-claim.workers.dev/dl/pyupd, writes the opaque payload to a temporary file, and launches it via subprocess.Popen with start_new_session=True as a detached process. The fetch is wrapped in a bare try/except that suppresses errors, there is no hash or signature verification, the version is not pinned, and the destination host is unrelated to any declared publisher or project homepage. The package name is a one-character edit of the widely used 'semver' name, consistent with a typosquat lure whose only purpose is to trigger the install-time dropper.

Source: kam193 (857ac41cf6480d83178766eebe04f79d075cc1f35be8b13b612c33b22e7ab434)
During installation, package downloads and executes malware.

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Category: MALICIOUS - The campaign has clearly malicious intent, like infostealers.

Campaign: 2026-10-semvver

Reasons (based on the campaign):

- Downloads and executes a remote executable.

- malware

- typosquatting

Indicators of compromise

Shown defanged and not clickable. Search any indicator to find other packages using it.

Domains

URLs