I have always had Windows computers until July this year when I made the change to Mac with the 27" model. I was under the impression that Macs were pretty safe from viruses so I have only just chosen to install Avast today. I have not visited any 'dodgy' sites so imagine my surprise when Avast discover not one, but two trojans, Win32:Crypt-QOF and JS:downloaderownloader.DPI I am hoping that whilst these were present on my Mac, they would not have been able to be very active, and I was wondering whether anyone has any views on this. It was easy to delete them, although it is not always that easy to delete viruses on a PC, which leads me to believe they were just there and not activated. This can also serve as a warning that Macs are not immune to viruses, and I haven't used mine a great deal since I had it. I'd be interested to read any thoughts or comments about this, apart from the obvious statement that I should have installed antivirus sooner!