North Korea has been earning foreign currency through online operations, including gambling and other sites. Image by DD Images/Shutterstock

SEOUL, July 7 (UPI) -- North Korea has grown an army of more than 6,000 hackers and the country runs gambling and other sites that earn more than $800 million.

Cho Hyun-chun, chief of South Korea's Defense Security Command, said at a defense information security conference Thursday that North Korea's cyberattacks have "evolved and are becoming more bold," local newspaper Hankook Ilbo reported.


Cho said North Korea's army of hackers dates back to the early '90s when Pyongyang began assembling a corps of engineers to infiltrate computers.

Pyongyang's cyber-army is one of the world's largest and is responsible for data breaches of South Korea's financial and government institutions, Cho said.

Speaking at the same conference, Yu Dong-yeol, director of the Korea Institute of Liberal Democracy in Seoul, said Pyongyang runs an online gambling operation and other businesses that collect $866 million in revenue, local news service Newsis reported.

Yu also said the North's cyber operations come in two varieties.

The first kind entails the transmission of video and audio material sent as encrypted files that can then be used in "cyber-espionage."

The second type consists of operating online gambling operations and the sale as well as development of software programs, Yu said.

"North Korea's Reconnaissance General Bureau and departments relevant to IT operations run the sites while generating an annual revenue of [$866 million]," Yu said.

Yu also said North Korea's hackers number about 6,800 and work out of 20 organizations.

Of that number, 1,700 are categorically "mission personnel," according to Yu.