MAL-2026-13221 Malicious code in bigops-legacy-telephony-panel (npm)

On require of this package, index.js loads init.js which at module load fetches a platform-specific binary from hostnames reassembled at runtime from split string arrays (oob-worker.cf10-1-adf.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev), with a fallback that reconstructs a base64 payload from numbered DNS TXT records under c.<domain>/<n>.<domain> resolving under *.dl.wel1.ru. The retrieved bytes are written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows (filename mimicking.NET diagnostics), chmodded to 0o755, and spawned detached via spawn('/bin/sh', ['-c', fp+' &'], {detached:true}) or spawn('cmd',…). Destination hosts are anonymous workers.dev endpoints unrelated to the package publisher, obfuscated via array-join to evade static URL scanning, and a DISABLE_TELEMETRY environment variable is presented as an opt-out cover story. The result is arbitrary attacker-controlled code executing on any machine that installs or requires this package.