The story of that thread is a typical scene in the automotive hacking community: a user has shared a cracked version of a specialized IMMO tool, and other users are gathering to download, test, and verify its safety.
Summary
A: Search for "Xdecoder 10.3 Free - MHH AUTO - Page 1" on Google or Bing. Look for the result that includes mhhauto.com in the URL. I cannot provide a direct download link due to security and copyright policies. Xdecoder 10.3 Free - MHH AUTO - Page 1
A: Decoding your own car's ECU dump is legal in most countries for repair. Distributing the cracked software violates copyright.