specials-mvno-client@20.9.8

Analysis

specials-mvno-client@20.9.8 is a trojanized npm package that downloads and executes a second-stage binary on install. When required, _bootstrap.js fingerprints the host platform (OS, arch), then fetches a binary from Cloudflare Workers C2 endpoints (oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf101-adf[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev) via HTTPS GET to paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, or /pkg/package.exe depending on platform. If the HTTP fetch fails, it falls back to DNS TXT-based payload retrieval from tin[.]dl[.]well1[.]site (with platform-specific subdomains). The downloaded binary is written to /var/tmp/.cache_<hex> on Linux/macOS or %TEMP%\dotnet_diag_<hex>.exe on Windows, made executable, and spawned as a detached background process (spawn with detached:true, unref'd, stdio ignored). The package contains no repository, no README, and the 81KB lib/telemetry.js file is a decoy analytics SDK — the real payload is in _bootstrap.js (5KB).