While ransomware has sadly been a reality on smartphones and Windows PCs for a while, you haven't really had to worry about it on a Mac... until now, that is. Palo Alto Networks claims to have discovered the first known instance of OS X-oriented ransomware in the wild, "KeRanger." If you install software infected with the code (in this case, a version of the BitTorrent client Transmission), it'll encrypt your files after three days and demand that you pay a digital currency ransom to regain control.