devplatform-s3-uploader@35.4.4

Analysis

devplatform-s3-uploader is a trojanized S3-uploader wrapper that, when required, downloads and executes a second-stage binary. It fetches a platform-specific payload over HTTPS from Cloudflare Workers hosts oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev, and oob-worker[.]cf101-adf[.]workers[.]dev at paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, and /pkg/package.exe, with a DNS TXT-based fallback via c[.]sdk[.]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 detached via /bin/sh -c "&" or cmd.exe /c start /b. The package ships a large decoy telemetry module (lib/telemetry.js) while the real dropper logic lives in _helpers.js.