It sounds like something out of a movie.
Neon-lit streets in Shenyang, China, are home to a network of North Korean owned businesses. Hotels, restaurants and even a secret group of roving hackers are nestled in safety, according to CNN.
The hacker network is called Bureau 121, said defector and former Pyongyang computer science professor, Kim Heung-Kwang.
"It's easy for them to work secretly. It also has great Internet infrastructure," Kim told CNN.
Some of Kim's students even went to work for Bureau 121, becoming warriors in a cyber battle. "By day, they worked regular jobs. But the rest of the time, they were acting on orders from Pyongyang," Kim told CNN.
"Bureau 121 began its large-scale operation in China in 2005. It was established in the late 90s," Kim explained to CNN."Team members entered China separately - in smaller groups - 20 members at a time. When they entered China, they came under different titles. For example an office worker, an official with a trade company or even as a diplomatic staffer."
From then when North Korea didn't have its own internet through today when North Korea has its own high speed internet access, North Korea's internet traffic is still driven though Chinese servers.
"North Korea does have illicit activities in China," said Steve Sin, a terrorism expert at the University of Maryland and former U.S. military intelligence analyst, according to CNN.
The northeastern Chinese city Shenyang has been named by Sin in a report as the hacking hub of North Korea. "It has the location, security, as well as infrastructure," Sin told CNN."Right now, the best information available to us is that they are still conducting such an operation and they can still conduct such an operation from that location."
North Korea officials refused to comment, according to CNN. China asserted its opposition to illegal cyber activity.
