MAL-2026-12937 Malicious code in bnpl-blocks-desktop-bnpl-popup (npm)

The package's main entry loads init.js on require. init.js selects a platform-specific URL, assembles C2 hostnames at runtime via string-split/join to evade static analysis (e.g. 'oob-worker.cf99-9b3.workers.dev' family, with a DNS TXT covert-channel fallback over *.dl.wel1.ru where 'c.<domain>' returns a chunk count and 'i.<domain>' returns base64-encoded payload chunks), downloads an opaque executable, writes it to /tmp or the Windows temp directory under a decoy name such as dotnet_diag<hex>.exe or.cache<hex>, chmods it 0755, and spawns it detached through /bin/sh -c or cmd.exe. Behavior is gated only by a stamp file and opt-out environment variables. The package presents itself as UI popup components, which has no legitimate reason to fetch and run a platform-specific binary from anonymous Cloudflare Workers endpoints at import time.