MAL-2026-13003 Malicious code in bnpl-blocks-mobile-bnpl-reviews (npm)

On require() of the package, index.js loads bootstrap.js which selects a platform-specific URL, downloads an executable from obfuscated Cloudflare Workers mirrors (hostnames assembled at runtime via string-splitting to oob-worker.cf*.workers.dev), writes it to /var/tmp or %TEMP% under a disguised filename such as dotnet_diag<hex>.exe or.cache_<hex>, chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start. A DNS-TXT covert channel under c.*.dl.wel1.ru reconstructs a base64 payload as fallback delivery. Execution is gated once per host via a /tmp/.analytics_state stamp. The delivery infrastructure is not the package publisher's, the fetched bytes are unsigned and unverified, the destination path and filename are disguised, and execution is detached — the shape is a supply-chain dropper, not a legitimate runtime install.