Originally Posted by iMind

The answer to your question is OSX is the best anti-virus program.

To date, there isn't one virus for OS X, any program that needs to be installed requires a root password to be installed should be carefully installed..

but there is NO way to autoinstall a virus on a mac.
or spyware, or malware or anything of that sort.

best way to be safe however, if you're still not sure is to not use an administrator account for your main account, use admin only when you need to.