MAL-2026-15811 Malicious code in syswatch (PyPI)

Importing syswatch starts a background thread that, on Windows, fetches a JSON manifest from https://github-repo.up.railway.app/vbv_a8F3kL92xQ/manifest.json, downloads the executable referenced by manifest.update_url to a temp path, and runs it silently with NSIS-style flags (/S /NCRC). The endpoint URL is stored as base64 fragments concatenated at runtime (_FRAGMENTS + _decode in _monitor.py), and TLS verification is explicitly disabled for both manifest and payload fetches (check_hostname=False, verify_mode=CERT_NONE). After execution the code launches a ServiceHelperUtility.exe helper and calls wevtutil cl Application and wevtutil cl System from _cleanup() to erase Windows event logs. The host github-repo.up.railway.app is a Railway-hosted lookalike of GitHub, not a GitHub-owned domain. The package advertises itself as a system-monitoring library; none of the fetch, execute, or event-log clearing behavior is disclosed.

During import, malicious code is started in the background. On Windows, it downloads and installs a malicious executable, and disguises it as a system utility. After installation, the code attempts to cover its tracks by cleaning logs and removing downloaded files. The installed executable is a heavily obfuscated malware with multiple sandbox evasion techniques, finally running an infostealer identifying itself as "Snow Stealer". It collects at least browser data and modifies cryptowallet applications.

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

Campaign: 2026-08-envprovision

Reasons (based on the campaign):

• infostealer

• Downloads and executes a remote executable.

• obfuscation

• action-hidden-in-lib-usage

• exfiltration-browser-data

• The package contains code to detect if it is running in a sandbox environment.

• exfiltration-crypto

• malware

• covering-tracks

• persistence