bigops-notes@35.8.7

Analysis

bigops-notes@35.8.7 is a multi-stage dropper disguised as a notes SDK. Requiring the package runs _bootstrap.js, which fingerprints the OS/CPU and downloads a platform-specific second-stage binary over HTTPS from oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf101-adf[.]workers[.]dev, and oob-worker[.]cf103-070[.]workers[.]dev (paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe). If HTTPS fails it retrieves the payload via DNS TXT records under c[.]sdk[.]dl[.]wel1[.]ru (base64-decoded). The payload is written to /var/tmp/.cache_<hex> (or %TEMP%\dotnet_diag_<hex>.exe on Windows) and executed detached via cmd.exe /c start /b or /bin/sh -c, so it runs in the background and outlives the parent. Execution is rate-limited to once per ~5.6 hours via a stamp file.