Now Playing: 10-07-13 Marketplace Tech - What is a 'Zero Day'?

In the ever-expanding world of hacking, there is a dictionary. Not a literal book of words and definitions but a list of phrases you have to know. And one of those phrases is Zero Day. It's not a day -- or a cop thriller with Bruce Willis in it -- it’s just a special kind of computer code that can do anything from break into a bank to steal someone's online identity. And Zero Day exploits are getting more and more popular.