If your anti-virus checker warns you about the Trojan “Win32/Wacatac.C!ml”, it’s a false positive.
fp2fms is built as a Java .jar file. This allows fp2fms to run on windows, Mac and Linux with the same Java .jar file. For windows, it is compiled into an executable (fp2fms.exe) file along with only components from OpenJDK. This bundling with OpenJDK is done so you can run fp2fms (on any platform) without having to install additional software (Java runtime libraries).
The website www.virustotal.com ran 50+ anti-virus checkers on the fp2fms.jar file and found 0 warnings. When fp2fms.exe was analyzed, out of the 70+ anti-virus checkers that were run, only 5 of them generated alerts. These had to be from the OpenJDK libraries since those libraries are the only additional software that is added to the fp2fms.jar file to produce the fp2fms.exe file.
OpenJDK is used by millions of Java developers all over the world and is safe to use. Thus, the fp2fms.exe virus alerts are false positives as well. However — having said all of this, if you are still uncomfortable using fp2fms because you received a virus warning, then please do not use fp2fms.