this is being called the world's biggest cyber attack, and not even over yet. chief business correspondent christine romans in the money center. what do we need to know? >> millions wake up and logon the infection is flslowing. it hit 200,000 users in 150 countries. there could be more today. new attacks reported in china, japan and korea. the virus locks users out of their computers, and then demands hundreds of dollars to regain control. global companies like fedex and nissan as well as hospitals in the uk, universities in china, german train networks have all been hit. the ransomware targets a flaw in microsoft windows that microsoft patched in march but the virus hit networks that had not updated their systems.