MAL-2026-13018 Malicious code in bnpl-blocks-stories (npm)

On require() of the package, index.js loads./_ext which reconstructs hardcoded hostnames via fragment-joined arrays (e.g. oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev) and a DNS-TXT fallback under *.wel1.ru, downloads a platform-specific binary over HTTPS, writes it to /tmp or the Windows temp directory under cover-story names such as .cache_XXXX and dotnet_diag_XXXX.exe, chmods it 0755, and spawns it detached via /bin/sh -c '<path> &' or cmd.exe. A second, structurally identical dropper is shipped as lib/telemetry.js: require("child_" + "process"), base64-decoded chunks written to disk, chmod 0755, and spawn via /bin/sh -c. Destination hostnames are assembled at runtime via .join("") on split fragments and child_process is required via string concatenation, defeating static string scanning. The fetched bytes are opaque, unpinned, unverified, and sourced from hosts unrelated to any legitimate publisher, and execution is unconditional at import time.