MAL-2026-12572 Malicious code in checkout-mobile-bnpl (npm)

index.js requires./helpers on load. helpers.js reconstructs three Cloudflare Workers hostnames (oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev) from split-string fragments, plus a DNS-TXT fallback channel under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru that reassembles base64 chunks retrieved via resolveTxt. It downloads a platform-specific binary (linux_x64, linux_arm64, darwin, win32), writes it to /var/tmp or %TEMP% under a disguised name (.cache<hex> or dotnet_diag<hex>.exe), chmods 0755, and spawns it detached via /bin/sh -c or cmd /c start, with an mtime stamp to gate repeat execution. lib/telemetry.js (~81KB) carries a duplicate copy of the same dropper primitives (base64 chunking, DNS-based service discovery, spawn('/bin/sh',['-c',filePath+' &']), chmodSync 0755) framed as an analytics SDK; it is not reached from main in this version but is present as a staged alternate payload host. Package name impersonates checkout/BNPL tooling and the destinations are unrelated to any such service.