From AppleInsider this afternoon:
Security researchers recently discovered that more than 17,000 Macs around the world have been infected by a new OS X malware threat called “iWorm,” which at one point used Reddit.com as a go-between to cull user data, perform various system actions and execute Lua scripts.
Yes, indeed, there are viruses, malware, and other not-so-nice bits and bobs out there that like to call Macs home; you really do need to be running anti-bad-stuff software on your Macs. ‘iWorm’ malware controls Macs via Reddit, more than 17K affected has the gory details, including how to tell if you’ve been invaded. Check it out; I have spoken.