The Chinese military attempted to hack into computers at the South Korean Embassy in the United States last year, a South Korean Air Force publication said Wednesday.
According to the annual publication that details the defense capabilities of global powers, China operates a "Red Hacker" unit of about a million hackers mainly attacking the U.S., Japan and Taiwan.
The hackers, including those recruited from U.S. institutes such as MIT, attempted to hack systems at the South Korean Embassy in March last year, the publication said, citing military intelligence.
"It was concluded based on the tracing of the Internet Protocol address that the attempt came from a Chinese military hacking unit," it said.
The case marks the first time South Korean has made it public that it believes the Chinese military has tried to hack into its diplomatic office abroad.
Last year, a South Korean ruling party lawmaker said China had hacked at least five times into South Korean military units until October.
The attempts were made through the use of emails that spread hacking viruses once opened by users, Kim Dong-sung said, citing a report by the Defense Security Command.
Kim also raised the possibility that North Korea could be behind such activities via China.