MAL-2026-14142 Malicious code in testingsmthb1g (npm)

scripts/postinstall.js runs at npm install and performs an install-time dropper chain. A URL stored as an integer array is XOR-decoded (key 'stf2026') to https://github.com/bebraz1/qPzM50V1AKG0rVlH/releases/download/null/main.exe — a personal GitHub account unrelated to the package publisher, at a random-named repository with a mutable 'null' release tag. On Windows, the script downloads this binary to the TEMP directory and spawns it detached with stdio ignored. On WSL/virtualized Linux, the script detects the environment via /proc/version and WSL_DISTRO_NAME, assembles an XOR-decoded PowerShell command line, and executes it via exec() to fetch and run the same payload on the Windows host, escaping the Linux sandbox. In parallel, the script POSTs a platform label to a hardcoded bare-IP endpoint http://193.70.34.101:20099/vote whose hostname is constructed via split-join to evade string matching. The destination URL, PowerShell command, and shell fragments are all XOR-obfuscated integer arrays reconstructed at runtime.