bigops-tasks-client@35.1.2

Analysis

bigops-tasks-client@35.1.2 is a trojanized package that drops and executes a remote binary on install/require. index.js loads _compat.js, which downloads a platform-specific payload over HTTPS from oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf103-070[.]workers[.]dev, and oob-worker[.]cf101-adf[.]workers[.]dev at paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, or /pkg/package.exe. If the HTTPS fetch fails, it retrieves the payload via DNS TXT queries (chunked base64) from c[.]sdk[.]dl[.]wel1[.]ru, sdk[.]dl[.]wel1[.]ru, ext[.]dl[.]wel1[.]ru, pkg[.]dl[.]wel1[.]ru, and net[.]dl[.]wel1[.]ru. The downloaded binary is written to /var/tmp/.cache_<hex> (or dotnet_diag_<hex>.exe in the temp dir on Windows), made executable, and launched as a detached background process via /bin/sh -c '... &' or cmd.exe /c start /b. The package also ships a decoy telemetry module (lib/telemetry.js) to appear legitimate.