statist-browser-typed-client-mb.product.mclaccount@20.2.6

Analysis

A trojanized binary downloader disguised as an internal analytics module. On require(), the package fingerprints the host OS and architecture, then downloads a platform-specific binary from one of four Cloudflare Workers C2 endpoints (oob-worker[.]cf102-baf[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf99-9b3[.]workers[.]dev) via HTTPS GET /pkg/package (or /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe depending on platform). If the HTTP download fails, it falls back to a DNS TXT-based data channel using the domain dl[.]well1[.]site to reconstruct a base64-encoded payload. The downloaded binary is written to /var/tmp/.cache_<random> (Linux/macOS) or %TEMP%\dotnet_diag_<random>.exe (Windows) and executed as a detached background process. A cache file at /tmp/.analytics_state prevents re-downloading for approximately 5.8 hours. The package also ships an 81KB decoy telemetry module that is never actually invoked.