MAL-2026-6750 Malicious code in procwire (PyPI)

setup.py auto-executes on pip install (only guarded by an internal _PW_DIST env var check) and, on Windows, reconstructs an attacker C2 URL and XOR key at install time by pulling byte blobs from mandatory sibling dependencies schemavault (schemavault.registry._k, _ep, _p) and bytekit (bytekit.xor). The reconstructed URL is fetched with TLS verification disabled and a spoofed User-Agent, downloaded to a randomly-named.exe under %LOCALAPPDATA%\Temp / %TEMP% using disguised names (svcupdate, wuaclient, netfx_host, msedge_pwa, synchost), XOR-decoded, stripped of its Zone.Identifier mark-of-the-web ADS, and executed hidden via Popen with STARTF_USESHOWWINDOW / DETACHED_PROCESS, with fallbacks through cmd /c start /min and powershell -WindowStyle Hidden, plus a curl fallback for the download. The runtime module procwire/bridge.py implements a plausible subprocess-management API but never imports schemavault or bytekit — those dependencies exist solely to smuggle the C2 URL and decryption key past static review of procwire itself. Author metadata (Dmitri Petrov <[email protected]>) is consistent with a throwaway publisher identity. Installing this package on Windows runs attacker-controlled code with the installer's privileges.

The campaign consists of multiple packages. The trigger sits in the package 'procwire,' which depends on two others. During installation, procwire uses schemavault and bytekit packages. The first one holds the URL holding malware (in two places, once as steganography in the bundled image and once as a fallback just as a list of encoded bytes). The bytekit implements simple custom decoding used to retrieve back the URL in the fallback method. Additionally, procwire is also a dependency of confighub, turning another package into malware. The downloaded executable is run and quickly removed. The executable likely contains an infostealer and contacts the domain 030502[.]xyz

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

Campaign: 2026-07-procwire

Reasons (based on the campaign):

• The package overrides the install command in setup.py to execute malicious code during installation.

• Downloads and executes a remote executable.

• obfuscation

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

• malware

• steganography