A new trojan called Trojan.Yontoo.1 is going after Macs. If you run into it, Yontoo.1 prompts you to install a browser plugin called "Free Twit Tube" or something similar. When it's installed, it injects ads into your browser.
If you haven't installed anything weird lately, you should be OK, but be careful if you come across a strange download. [The Next Web]