ClamXav is a free virus checker for Mac OS X. It uses the tried, tested and very popular ClamAV open source antivirus engine as a back end.

Back in the days before OS X, the number of viruses which attacked Macintosh users totalled somewhere between about 60 and 80. Today, the number of viruses actively attacking OS X users is...NONE! However, this doesn't mean we should get complacent about checking incoming email attachments or web downloads.