[KLF] Re Virus

Hey, I join my first ever list and the busy traffic is all about viruses. I thought the internet was now a tame place, its wild west days long gone ;) At the risk of sounding stupid, do I need to do anything about this virus? I use various computers to log on to my email account, mainly a Mac running OS X. I've searched my hard-drive but can't find any suspicious looking files or folders. Cheers in advance, Angus