Researchers believe North Korea may be behind the global cyberattack that targeted 150 countries last week, affecting more than 300,000 computers.
According to Symantec and Kaspersky Lab, some of the code that was found in the WannaCry software was also used in some programs run by the North Korea-affiliated Lazarus Group.
"This is the best clue we have seen to date as to the origins of WannaCry," Kurt Baumgartner, a researcher at Kaspersky Lab, told Reuters.
The researchers said it was too early to confirm that Pyongyang was behind the cyberattacks. The researchers said they would have to study the code more.
The idea that North Korea could be behind the attack is not a reach. Both U.S. and European officials told the news agency that North Korea should not be ruled out as a suspect.
Hackers for the Lazarus Group were blamed for the theft of $81 million from the Bangladesh central bank. The 2014 Sony hack was also pinned on the hacker collective.
Steven Wilson, Head of Europol’s European Cybercrime Center, told Sky News on Sunday that it while it was “not a massively sophisticated attack,” what is striking about it is the “use of a worm to propagate through systems.”
“It is beyond anything we have seen before,” he added.