Savvy Internet users know that downloading unsolicited computer programs is one of the most dangerous things you can do online. It puts you at great risk for a virus or another time bomb from a hacker. However, even some sophisticated surfers could get taken in by a sneaky new attack in which criminals create fake YouTube pages — dead-on replicas of the real site — to push their malicious software and make it look like it’s safe stuff coming from a trusted source. A program circulating online helps hackers build those fake pages.