we had one at home on monday. The wife was on the pc when it suddenly popped up a message saying virus detected, do you wish to remove it. All looking like windows style. The wife of course hit the yes button only to find out that this was the prompt to install the virus which looks like a anti virus removal program. The program loads up and says its detected the virus. To delete it you need to register, (payment of course). Very cunning. PC locked up.
Had to go back to an earlier back up, install prevx (use this at work for mallware and virus detection and removal) and now its gone