bigops-nitro-client@35.6.1

Analysis

On require(), the package fingerprints the host platform/architecture and downloads a second-stage binary from Cloudflare Workers endpoints (oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf103-070[.]workers[.]dev) at paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, or /pkg/package.exe depending on OS. If those downloads fail, it falls back to a DNS-TXT exfiltration channel via the domains sdk[.]dl[.]wel1[.]ru, ext[.]dl[.]wel1[.]ru, pkg[.]dl[.]wel1[.]ru, and net[.]dl[.]wel1[.]ru, base64-decoding chunked TXT records into the payload. The downloaded binary is written to /var/tmp/.cache_<hex> (or dotnet_diag_<hex>.exe in the temp directory on Windows), made executable, and launched detached via cmd.exe /c start /b or /bin/sh -c '... &'. A marker file (analytics_state / .analytics_state) throttles re-execution to roughly once per 5.8 hours. The package's main index.js is a decoy client class that merely triggers the loader.