MAL-2026-13201 Malicious code in dp-web-header (npm)

The package advertises itself as a web header library but its index.js unconditionally requires ext.js on load. ext.js downloads a platform-specific binary from hardcoded Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev), writes it to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag<hex>.exe on Windows, chmods it 0755, and spawns it detached via spawn('/bin/sh',…) or spawn('cmd',…). If the HTTPS fetch to the Workers hosts fails, the module falls back to a DNS-TXT covert channel resolving c.<domain>, 0.<domain>, 1.<domain>,… under sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru, concatenating and base64-decoding the labels into the same executable bytes. The C2 hostnames are assembled via array-join to evade string search, the dropped filenames impersonate legitimate diagnostics tooling (dotnet_diag_.exe,.cache_), a marker file.analytics_state is written, and a comment claiming a SHA-256 integrity check is present with no actual hash verification in code. Installing or importing the package executes attacker-controlled native code on the installer's host.