I wanted to play around with some altcoins but many of the main websites are sketch at best. For example when checking out UltraCoin, their recommended miner has spyware in it. What altcoins can you trust?
Sometimes miners have "false positive" something when you check them with antivirus programs. But they are just built that way that antivirus thinks so.
Best for you is to take some time and follow coins and their communities. With time you will find out what is their intention.