The personal information of about 100,000 people was leaked in a recent hacking attack on the presidential office.
A presidential official who spoke on the condition of anonymity, told Yonhap News Agency on Sunday, said the compromised information includes names, birth dates, identification numbers, offline addresses and IP addresses.
However, users' passwords and their registration numbers--the equivalent of U.S. social security numbers--were not stolen since they were encrypted.
The presidential office has offered an apology over the leakage of its users' personal information and said the hacking victims, who account for about half of registered users of its Web site, can seek compensation, according to Yonhap.
Last week, unidentified hackers attacked the Web sites of South Korea's presidential office and government policy coordination on the anniversary of the outbreak of the 1950-53 Korean War. Hacktivist group Anonymous had claimed responsibility for the attacks, though.