MAL-2026-12904 Malicious code in bnpl-blocks-atom-icon-loader (npm)

On require of the package, index.js unconditionally loads compat.js, which selects a platform-specific output path (Linux/Darwin: /tmp/.cache<rand>; Windows: TEMP/dotnet_diag_<rand>.exe), downloads an opaque binary via https.get from one of several Cloudflare Workers subdomains (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev), writes it to disk, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start. Destination hostnames are assembled at runtime by joining split string fragments (e.g. ['oob','-worker.cf99-9b3.workers.dev'].join(''); ['sdk.dl.w','el','1.r','u'].join('')) to evade static URL scanning, and a DNS-TXT chunked base64 fallback channel targets sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. Cover-story comments referencing SHA-256 integrity checks, CI skipping, and exponential backoff appear in code that implements none of that logic. The dropped Windows artifact is named dotnet_diag_<rand>.exe to masquerade as a Microsoft diagnostic tool. No signature verification, no pinning, no publisher-matching source.