The Seoul Central Prosecutors' Office on Sunday charged two South Koreans with cooperating with North Korean hackers in China to run illegal websites and steal the personal information of millions of individuals.
Investigators discovered the personal data of 140 million South Koreans on their computers and believe they could have shared the information with North Korea.
Among the data some 1000 were found to be obtained from a North Korean agent and a hacker in 2011
"The data were obtained by hacking into the websites of department stores, gas stations and online shopping malls as well as from illegal dealers," a prosecution spokesman said. "If this information was passed on to North Korea, the North has a significant amount of personal information about South Korean individuals."
One of the two men, identified by his surname Choi, is suspected of contacting the North Korean agent and the hacker regularly since 2007. He is accused of receiving hacking and spam mail programs developed by North Korean programmers, as well as computer software used to manipulate South Korean gambling sites and profiting from them.
Choi also had administrator access to around 68,000 South Korean Internet sites and used it to post ads luring users to pornographic websites.
The personal information found in Choi's possession included email addresses and resident registration numbers. Choi had apparently categorized the information to use for various purposes.
North Korea has used such information to conduct cyber attacks or to post messages on South Korean websites attempting to split public opinion here. Authorities here also believe it may have been sold to Chinese and Taiwanese crime organizations to use in voice phishing and telephone fraud.