MAL-2026-13011 Malicious code in bnpl-blocks-mobile-large-bnpl-reviews (npm)

On require() of this package, loader.js selects a platform-specific asset path (/pkg/package, /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe), downloads it over HTTPS from attacker-controlled hosts whose hostnames are reconstructed via split-and-join string obfuscation (oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev), with a covert DNS TXT base64 fallback channel to sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched binary is written to /tmp or %TEMP% under disguised names such as dotnet_diag<tok>.exe or.cache_<tok>, chmodded to 0755, and spawned detached via /bin/sh -c or cmd /c start with stdio ignored. There is no signature or hash verification, and the require() of child_process is itself obfuscated (require("child_" + "process")). Cover-story opt-out env vars and analytics/dotnet_diag filenames provide plausible-deniability framing.