MAL-2026-13075 Malicious code in boxy-pkg-deps-hash (npm)

On require() of the package, index.js loads adapter.js and unconditionally invokes setup(). setup() downloads a platform-specific binary from hardcoded Cloudflare Workers hosts whose names are assembled at runtime via array-join to defeat string search (oob-worker.cf102-baf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev). The fetched bytes are written to /tmp or %TEMP% under disguised filenames (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh -c or cmd.exe /c start. If HTTPS retrieval fails, _adapter.js falls back to a DNS-TXT covert channel: it resolves TXT records under c.<subdomain>.dl.wel1.ru to get a chunk count, then TXT records under N.<subdomain>.dl.wel1.ru to reconstruct base64 chunks, concatenates and decodes them to the same binary, and executes it via the same write/chmod/spawn path. The destination hosts are anonymous *.workers.dev endpoints unrelated to any declared publisher, and env checks use benign-sounding cover names (DISABLE_TELEMETRY/DO_NOT_TRACK). Any import of the package results in full-host remote code execution on the installer.