You've read the board rules, I assume? We cannot specify particular sites where roms may be found. As a matter of interest, I tried both games, and they worked without any file problems, and no slowdowns either.
Wrong checksum, files missing: You need to download the correct files from a reputable romsite (we cannot say where). Once you've gotten past the file issues, then tell us what happens.
Probably just a false positive, after all with all the millions of visuses out there sooner or later another program will happen to have the same sequence of bytes.
Once it does accept your roms, it will want to set up its NVRAM. This can take an hour, but you only have to do it once. Unless, of course, you run the non-cd version.
The file should be inside of a zipfile called sfiii3 (or similar). The zipfile belongs in your ROMS folder. Also, since your file has the incorrect CRC, you should download the latest version from a reputable rom site.