MD5 & SHA Checksum Utility is a reliable tool used to verify the integrity of files that you download or transfer from one computer to another. It compares the hash values of the original file and the downloaded or transferred file to make sure that they match. This utility is widely used and trusted by many users.
Regarding the false positives reported by VirusTotal, it is not uncommon for security software to flag legitimate software as malware. It could be due to a similarity in the code or behavior of the legitimate software to a malware strain, or it could simply be a false alarm. Therefore, I would not worry too much about the three entries reported by VirusTotal if you have downloaded the tool from a trusted source.
If you are still concerned, you can also try scanning the tool with other antivirus software to get a second opinion. Nonetheless, if you downloaded the tool from a reputable source and the provider has a good reputation, there is nothing to worry about.
I hope this helps!