The notion that any internet connected computing device is immune from infection or attack is really foolish. What most Apple owners don't understand is that their computers have been spared the assaults normally reserved for PC (read - Microsoft) owners only because the relative number of Macs to PCs was so small. Even now - as the article suggests - there are roughly 13 PCs for each Mac in the world. That ratio certainly suggests that targeting PCs - if attackers are so inclined - should be 13 times as widespread or effective.
New Mac malware epidemic exploits weaknesses in Apple ecosystem | ZDNet