prokit-core@20.6.6

Analysis

prokit-core@20.6.6 is a trojanized package that downloads and executes platform-specific binary payloads when imported. On require(), _helpers.js runs immediately: it fingerprints the OS/architecture (linux_x64, linux_arm64, darwin, win32), then attempts to fetch a binary from a rotating set of Cloudflare Workers C2 endpoints (oob-worker[.]cf101-adf[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev) at paths like /pkg/package, /pkg/package-arm64, /pkg/loader_mac, or /pkg/package.exe. If HTTP fetch fails, it falls back to a DNS TXT-record-based exfil channel via domains tin[.]dl[.]well1[.]site, tina[.]dl[.]well1[.]site, ldr[.]dl[.]well1[.]site, win[.]dl[.]well1[.]site — querying a chunk count at c.<domain> then reassembling base64-encoded chunks from numbered TXT records. The downloaded binary is written to /var/tmp/.cache_<hex> (Unix) or %TEMP%\dotnet_diag_<hex>.exe (Windows) and spawned as a detached background process (cmd.exe /c start /b on Windows, /bin/sh -c "path &" on Unix) that outlives the parent. A marker file at /tmp/.analytics_state or %TEMP%\analytics_state prevents re-execution within ~6 hours.