Compare the output with the official hash. If they do not match, delete the file immediately.
The (often found as auto_fh3.V7.exe or archived in a .7z file) is an automated setup script. It is primarily used for the Opus Developer Build of Forza Horizon 3. The tool automates several complex manual steps: Auto Fh3-v7-7z Tool Download
If you are unhappy with the changes, the tool includes a restore point creator. Before any major operation, it automatically creates a restore point. To revert: Compare the output with the official hash