MAL-2026-12582 Malicious code in checkout-molecule-mobile-status-sheet (npm)

On require() of this package, index.js unconditionally loads compat.js, which fetches a platform-specific executable from hardcoded Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), writes it to /var/tmp or %TEMP% under decoy names (.cache<hex> or dotnet_diag_<hex>.exe), chmods it 0755, and spawns it detached via /bin/sh -c or cmd. Endpoint hostnames are obfuscated by splitting them across string arrays joined at runtime to defeat static scanners. A DNS-TXT fallback channel under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru retrieves base64-encoded payload bytes across numbered TXT records and follows the same write-and-execute path, providing redundant covert delivery when HTTP egress is filtered. A TTL stamp file provides persistence between invocations. The package's advertised name bears no relation to the actual behavior.