Yes. The first virus for an Apple computer was created in 1982. The first virus for OS X (Mac.Leap) appeared in 2006. In early 2009, the Trojan Mac.Iservice infected machines that comprised the iBot zombie network. In 2012, half a million of computers were connected to the botnet created by the Trojan BackDoor.Flashback. It was Doctor Web who first discovered this zombie network.