Little-known anti-malware programs display warnings, which are often identified as false positive. Nevertheless, it is recommended to recheck the file with your antivirus software after downloading.
We do not have a download file for the latest version (3.1), but you can try downloading it from the developer's site
Download version 3.1 from the developer's website
Version: 3.1 (x64)
Date update: Dec 25, 2019
File name: bluegriffon-3.1.win-x86_64.exe
Size: 252 MB