Scan files with virustotal.com first. It's a legit site and it will always tell you if there is a virus.
Nope, that's one bad advice, virustotal will tell you a lot of times that there is a virus when there is none and fail when there is one.
There is no antivirus that can detect everything and protect you from all the viruses and there will never be as long as you try to use random cracks from shady websites. The best way of avoiding is either paying for the legit software, try to find an opensource alternative or, change the OS, relying completely on your antivirus is like wearing a bulletproof vest in a war, sooner or later you will get shot where you're not protected.
Hihi, there is one saying, "too poor to buy cheap things", it works for pirated software too.
Some 50$ saved with a cracked version might cost you twice or 10 times more, imagine getting a crypto locker and having months of worked destroyed.