Experts said earlier in the day that they had detected signs of a possible North Korean link to "WannaCry", a malware which spread through computers in key European countries and demanded to receive cash from users to release their sensitive files and information.
"It is similar to North Korea's backdoor malicious codes", said Simon Choi, a senior researcher with Hauri who has done extensive research into North Korea's hacking capabilities and advises South Korean police and National Intelligence Service.
"There is a link. We are really drilling down on what it means, but there is part of the code that is shared between WannaCry and a known DPRK hacking tool", he said.
Still, researchers say someone else could be using the code, and no one officially has been connected.
Researchers from the cyber security company Kaspersky Lab were then able to identify clear similarities between the group's code and that behind the WannaCry ransomware.
U.S. officials blamed both hacks on North Korea.
Mr Hutchins' manager at online security firm Kryptos Logic said he "not only saved the United States but also prevented further damage to the rest of the world".
Russian President Vladimir Putin, noting the technology's link to the USA spy service, said it should be "discussed immediately on a serious political level".
Researcher John Miller said: "The similarities we see between malware linked to that group and WannaCry are not unique enough to be strongly suggestive of a common operator".
And it was connected with last year's theft of $81 million dollars from a Bangladesh account at the Federal Reserve Bank in NY.
Beyond the immediate need to shore up computer defenses, the attack turned cyber security into a political topic in Europe and the United States, including discussion of the role national governments play.
The official declined to comment on intelligence-related matters.
A South Korean police official that handles investigations into hacking and cyber breaches said he was aware of reports on the North Korean link, but said police were not investigating yet.
North Korea has denied being behind the Sony and banking attacks. The hackers stole $81 million. The Lazarus Group is also reportedly behind the infamous Sony hack, as well as a breach at a Polish bank. He said based on his conversations with North Korean hackers, the reclusive state had been developing and testing ransomware programmes since August.
Regardless of the source of the attack, investors piled into cyber security stocks on Monday, betting that governments and corporations will spend more to upgrade their defenses.
Asia was hit hardest by the second wave Monday morning.