One of the wonderful things about being in the Linux world is that you can basically forget about viruses. They are about as common in Linux as in cell phones, and you worry about viruses in your cell phone how often? Yet there have been such viruses, but they are extraordinarily rare. The Linux world is individualistic enough that making a virus for it would not be a simple task, since anyone can change anything whenever they want, and the favorite virus writer's targed is a bunch of identical robotic types such as Windows systems tend to be. So it's no fun in Linux for virus writers.