Even Mac OS X risk infection by viruses. Published on the website of the company, where Apple recommends its users to use antivirus. There are suggested three commercial antivirus products, perhaps remember that are also free solutions as ClamXav.
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.
Download for 10.4 Tiger and 10.5 Leopard
