MAL-2026-18094 Malicious code in pafex (PyPI)

No install-time or import-time network I/O, credential access, subprocess execution, or other installer-harm behavior was observed in this package version. No lifecycle hooks performing privileged or external actions, no.pth side effects, and no evidence of exfiltration, dropper, backdoor, or silent-relay patterns.

In this campaign, the main package (resion) has an embeded pickle disguised as a config. A related dependency (pafex) contains code to load the pickle. During unpickling, malicious code embeded in the pickle file is automatically executed. It then establishes persistence via a PTH file and downloads the next stage payload. During analysis, the final remote payload was just a stub

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

Campaign: 2026-10-webreader

Reasons (based on the campaign):

• files-exfiltration

• obfuscation

• The malicious code is intentionally included in a dependency of the package

• Downloads and executes a remote malicious script.

• The package contains code to execute remote commands (probably limited to a specific set) on the victim's machine.

• rat

• persistence

• abuses-pth