With these caveats in mind, I think it is possible to draw a broad conclusion about the performance of behavior-based virus detection. In general, heuristics by itself does not seem to be as reliable as signature-based detection.
Free virus detection and virus removal tools, tools for the removal of hundreds of virus infections.
More basically, Pao suggests that you block any sort of malware downloads. One way to do that is to install spyware blockers that effectively prevent that type of program from loading malware onto your machine. Another is to enable the automatic virus-detection software delivered by most antivirus programs that checks every file when it is opened. In addition, the simple act of not opening attachments or navigating to links delivered by e-mail from senders you do not know will help prevent trouble before it begins.
Virex is the premiere Virus detection and removal application for Mac OS X. Although only an insignificant amount of viruses and malware exist for Mac OS X it's still recommended to scan for posterity's sake, and to prevent the spread of viruses to Windows-based computers. Learn more about free virus detection downloads.