devplatform-spa-ui@35.8.2

Analysis

devplatform-spa-ui@35.8.2 is a multi-stage dropper disguised as a UI component library. On require, it downloads a platform-specific second-stage binary over HTTPS from Cloudflare Workers endpoints oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf101-adf[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev, and oob-worker[.]cf99-9b3[.]workers[.]dev (paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe). If the HTTPS download fails it falls back to retrieving the payload in base64 chunks via DNS TXT queries against c[.]sdk[.]dl[.]wel1[.]ru. The downloaded payload is written to /var/tmp/.cache_<hex> (or dotnet_diag_<hex>.exe in the temp dir on Windows), made executable, and launched detached via cmd.exe /c start /b on Windows or /bin/sh -c <file> & on Unix. The payload executes without any install hook — merely importing the package triggers it.