ClamXav is not harmful but cannot prevent you from doing something stupid. Neither can anything else.
It is a common misconception that some magic shield exists that can make the inherently unsafe behaviour of downloading and installing software from torrent sites a safe activity. It's just not so. Installable software obtained in that manner is almost guaranteed to contain malware.
Popular "anti-virus" utilities use slick marketing tactics with confidence-inspiring characters like this
and this
They are highly effective marketing tools, but their products are for suçkers. Don't be one.
You have to "practice safe computing" on your own, and that means educating yourself about Internet threats and scams that will always be with us. If you do that, you will reach the same conclusions that have led to the recommendations I made.