What if you reached to grab a newspaper out of a news stand and you found a rock in your hand instead? How about opening the front door to a grocery store and ending up on a boat?

This sounds like a Matrix movie, but the virtual equivalent of this is real and poses one of the most serious new risks on the Internet, according to Jeremiah Grossman, chief technology officer and co-founder of Whitehat Security.

"Most exploits (like worms and attacks that take advantage of holes in software) ca...