MAL-2026-4231 Malicious code in pylogfmt (PyPI)

On import pylogfmt, the package's init.py spawns a detached background subprocess (subprocess.Popen([sys.executable, '_check.py'], stdout=DEVNULL, stderr=DEVNULL)) that runs an infinite loop POSTing the package install path to https://pypkg.dev/project/pylogfmt/json every 60 seconds with TLS verification explicitly disabled. The HTTP response body is base64-decoded and dispatched to a worker thread (threading.Thread(target=check, args=(package_list.decode(),))), which is the canonical remote-payload-dispatcher shape — the operator controls returned bytes and the client decodes and feeds them into a handler. The destination domain pypkg.dev is a lookalike of pypi.org/pypa with no relation to the package's declared logging-library purpose. Output suppression (DEVNULL on both streams), undocumented behavior (README advertises only a logging helper), TLS bypass, and lookalike C2 destination together are unambiguous attack signals. Any consumer that imports pylogfmt as a library leaks their install path to attacker infrastructure on a 60-second polling interval and is one server-side change away from arbitrary remote code execution.

Package silently executes remote code during import.

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

Campaign: 2026-05-lognest

Reasons (based on the campaign):

• Downloads and executes a remote malicious script.