After downloading the file (typically named Auto_FH3-v7-7z.7z or AutoFH3_v7_full.7z ), always verify its checksum. The official release should provide an MD5 or SHA-256 hash.
Even from a legitimate source, run a full antivirus scan. Tools that manipulate system files can sometimes trigger false positives (e.g., hacktool warnings), but it pays to be cautious.