Description

On require(), _shim.js reconstructs hostnames via string concatenation to hide destinations (oob-worker.cf*.workers.dev, with a DNS TXT-record base64 fallback under *.dl.wel1.ru), downloads a platform-specific binary, writes it to /var/tmp/.cache_XXXX on Unix or %TEMP%\dotnet_diag_XXXX.exe on Windows (masquerading as a.NET diagnostic file), chmods it 755, and spawns it detached with stdio ignored via cp.spawn("/bin/sh", ["-c", fp+" &"]) or the cmd equivalent. A TTL flag file suppresses re-execution. index.js re-exports lib/telemetry.js, which duplicates the same fetch/base64-decode/chmod/spawn dropper chain, providing a second import-time execution path. Dangerous API names ("child_process", "chmodSync") are reassembled at runtime via string concatenation to defeat static analysis. The package advertises itself as a data-transformation/analytics utility; the fetched binary is opaque and the delivery hosts are anonymous mutable Cloudflare Workers unrelated to any documented publisher.

Mitigation

Aliases