Police are chasing an individual loan broker who bought approximately 9 million items of personal data on South Koreans for 15 million won ($15,000) from a Chinese hacker between 2004 and 2006.
Police have put the man, now believed to be in China, on a wanted list for violating laws regarding the protection of personal information. The 42-year-old, only identified as Cheon, used the information to call credit defaulters and introduce them to private moneylenders.
He and his colleagues received about 2.5 billion won in fees from borrowers and moneylenders since 2007, police said.
Included in the traded data were online IDs, passwords, email addresses, social security numbers and other personal information.
He is also suspected of having resold the data to other moneylenders and other information providing companies.
``We've been surprised at the magnitude of the leakage of personal information,'' a police officer said. ``Given a growing number of Chinese hackers are targeting Korea's computer networks, the actual trafficking of this information could be a lot larger.''
Of the information, more than half was from six unidentified banks and other large lending firms.