Here's a program that got added to my computer when I visited a webpage with an infected advertisement. I'm told I probably moved the mouse over the ad, but I did not download anything or run anything. This particularly tricky malware program masquerades as a Microsoft Virus Scanner. It is NOT. It is very professional looking, but it is a wolf in sheep's clothing. Both of the messages below show messages how convincing this fraud is.

It was quite difficult to remove from my system.