Linux and Unix don't run viruses. An infected file isn't going to infect other files in a Unix/Linux environment, because they don't work that way.
You can download malware, but you have to A) give it rights B) execute it.
AstralExistence wrote:you know why there are more viruses for windows?' more users.
Wrong. Everyone depends on Linux on a daily basis whether you know it or not. Counting mobile OSes, desktops, and servers, there are probably more linux based computers than there are Windows based computers in the world.
Note that there's more valuable information protected on Linux servers, like banks, Google, and other companies that have large secure databases.