Transcript for New cyberattack freezes computers across the globe
That massive cyber attack hitting American companies including hospitals. Portable global assault on governments and businesses around the globe. Hackers locking up computers in demanding ransom to free them back up. The scheme similar to one just last month expert across 150 countries ABC's chief investigative correspondent Brian Ross on this new cyber attack. The fast moving cyber attack continues tonight after freezing computers at hospitals in Pennsylvania. Where surgeries had to be canceled its call me and says surgery has canceled because computers without also down computers that Merck pharmaceutical in New Jersey. Even the company that makes Oreo Cookies may have been hit as well as his Washington law firm which Warner's lawyers as they entered the lobby. You can't read in emails you can't read any files basically your computer becomes a brick. The attack first surfaced in Ukraine this morning. Shutting down everything from grocery stores to power companies airports in banks as the attacks spread across the globe including at this giant shipping company. The thousands of targets all receive this ominous message in English on their screens your files are no longer accessible. Nobody can recover your files without our description service send 300 dollars wears a bit calling him an active year data back. But hit you again in say give me more money. The attack bears great similarities to a similar computer a kidnap and ransom scheme last month that hit British hospitals particularly hard. But that attack literally to North Korea was stopped when cyber security experts discovered a kind of kill switch. And Brian Ross joins us now Brian as you mentioned that other attack there was to kill switch side is there one. With this when that will disarm that virus we'll tell them that we're hearing from both Russian and American cyber security experts they may have found a kill switch for this attack and they're trying to activate it now. But we won't really know until tomorrow if it works some encouraging news though.
This transcript has been automatically generated and may not be 100% accurate.