Number claimed to be Microsoft number to contact when computer screen taken over with 'Windows Security' warning of a trojan and dangers of being compromised. The number was to get help to fix the problem - more likely to cause it. There was also a zombie voice speaking messages of doom. I had to force shut computer (screen totally covered with flashing message, tickertape messages and dire warnings. I ran a full scan, consulted with Window Security and all was well. Nast scam attempt!