that computer, rendering it inoperable or inaccessible. for the operator to get access back to the files they have got to -- they have to pay a ransom. this is the modern day equivalent of a kidnapping or an extortion that someone is holding your files for ransom rather than a person. >> is this the biggest and the largest of this type of thing before this ransom ware, wanna cry stuff? >> i think it probably is. certainly in recent times. back in the early 2000s was saw the large scale cyber attacks and this particular one, because of the way that it's spreading not only is it spreading through traditional infection where you might open up a pdf file or quick a clink, but it's spreading through an exploit in microsoft where allowing for file sharing to occur across domains. that's why you're seeing these attacks in hundreds of countries because they're hitting multinational corporations that