Transcript for Trail of ransomware attacks could lead to North Korea
Now to another global worry at this hour. We have new reporting in the massive cyberattack. Hospitals paralyzed, surgeries halted and today we learned of an auto assembly line suddenly stopped because computers stopped down. Hackers affecting some 300,000 computers in 150 countries now, including the U.S. Locking those companies up and demanding ransom to free those files. New clues may be pointing to a familiar culprit. Here's Brian Ross. Reporter: Cybersecurity reseers say the trail could lead to North Korea, that the computer code that produced the so-called attack with these ominous messages, the code of a North Korea on attack on international banks last year. It could be someone using the north Korean code, says researchers. We have seen them steal money and information. We have seen them destroy information. Reporter: No official atricks to who was behind the massive attacks. As of tonight the tally of attacks has grown. More than 300,000 in 150 countries. Auto plants, offices, railways around the road. The most devastating, hospitals in great Britain, where ambulances were turned away. Cancer treatments and surgeries cancelled. Horrible. Cried a lot. Didn't really know what to say. Reporter: Only a few hundred companies appear to have followed the hackers' direction to pay $300 in ransom or more to have their files free, that, too, turned out to be scam. We're not aware of payments led to any data recovery. David, those attacks are still coming from that same group, Brian. That's right, new variant of the attack today and another one yesterday, but were shut down before they spread too far. What do you do? The most important thing is to download any upgrades, the fixes with the patches that block this attack. All right, Brian, thank you. To other news tonight, north
This transcript has been automatically generated and may not be 100% accurate.