Police in South Korea have reportedly arrested two people for hacking into the network of KT Corp., the country's second largest mobile carrier and selling the data.
According to a report by the Yonhap News Agency, police arrested a 40-yeard-old suspect – identified only by his family name of Choi – as well as a second person and accused them of leaking the personal information of roughly 8.7 million mobile phone subscribers since February.
Police suspect the telemarketers used the data, which contained information about the subscribers, their phones and monthly plans, to contact customers whose contracts were close to expiring or who were judged to be likely to change phone plans. Authorities estimate the suspects earned at least 1 billion won (US$877,000) from the illegal marketing scheme.
"It took nearly seven months to develop the hacking program and (the suspects) had very sophisticated hacking skills," an official at the National Police Agency's cyber terror response team told the Yonhap News Agency.
KT apologized for the incident, noting in a statement that it has recovered the leaked information and taken necessary steps to prevent any further leaks. The company asked police to investigate possible leaks July 13 after observing suspicious activities through internal monitoring, according to a report in BusinessWeek.
"In light of this incident, we will strengthen the internal security system and raise awareness of security among all employees to prevent causing inconvenience to customers," the carrier said in a statement to Yonhap.
A year ago, an even more significant breach occurred when hackers hit SK Telecom, yet another one of South Korea's large telecommunications companies. In that incident, personal information belonging to 35 million users of SK Telecom's Cyworld social networking service and Nate web portal were exposed.