Microsoft said it had taken control of the web areas that a hacker called "Thalium" had been using to steal information.
The American company published in a blog that Thallium Group operates from North Korea, and that the hackers targeted government employees, research centers, university members and individuals working in nuclear proliferation issues, among other things.
The company said most of the targets were based in the United States, Japan and South Korea.
Thallium conducted its operations through a technique known as "spear phishing", using credible emails that seemed legitimate at first sight.
Microsoft stated that it now controls 50 domains of the websites the group uses to conduct its operations, following a lawsuit against the hacking group at the US District Court in Eastern District, Virginia, and a subsequent court order.
The company said that Thallium used malware to seize systems and steal data, the fourth hacked group linked to North Korea that Microsoft is taking legal action against.