tcb-web-header @20.5.7

Summary

On require() of tcb-web-header, _platform.js selects an OS/arch-specific endpoint, downloads a binary from Cloudflare workers.dev hosts whose names are reconstructed at runtime by joining split string fragments (e.g. oob-worker.cf99-9b.3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev), writes the payload to /var/tmp or %TEMP% under a deceptive name (dotnet_diag_<tag>.exe on Windows,.cache_<tag> on Unix), fs.chmodSync to 0o755, and spawns it detached via /bin/sh -c "<path> &" or cmd.exe /c start /b. A base64-encoded chunked DNS TXT retrieval channel over c.<domain>/N.<domain> under tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site serves as a covert fallback transport when HTTPS is blocked. The package's declared purpose is a web header helper and there is no build/native-addon rationale for downloading and executing an unverified binary at import time; destination hosts are attacker-controlled, string-reassembled to defeat static scanners, and a token-gated DISABLE_TELEMETRY flag is used as a cover story.

Source: amazon-inspector (115bda849ee7aff33e1ccc649f492e892e31243bfb026eea8048c158c885bdf0)