tcb-web-copy-to-clipboard@20.1.2

Analysis

tcb-web-copy-to-clipboard is a combosquat package impersonating a clipboard SDK. On require(), it fingerprints the host platform and architecture, then downloads a platform-specific binary payload from a set of Cloudflare Workers C2 endpoints (oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf100-416[.]workers[.]dev, oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf101-adf[.]workers[.]dev) via HTTPS GET to paths like /pkg/package, /pkg/package-arm64, /pkg/loader_mac, or /pkg/package.exe. If HTTPS fails, it falls back to DNS-based payload retrieval via TXT record chunked queries to subdomains of dl[.]well1[.]site. The downloaded binary is written to /var/tmp/.cache_<random> (or %TEMP%\dotnet_diag_<random>.exe on Windows) and executed as a detached background process.