Top management staff of KT, the nation’s second-largest mobile carrier, on Friday made a public apology for the firm’s latest large-scale hacking incident and pledged to take measures to prevent a recurrence.

“The company has started developing countermeasures in response to incident, including the innovation of its online security system,’’ KT CEO Hwang Chang-gyu said during a press conference, which was held at the firm’s headquarters in downtown Seoul.

His apology came one day after it was found that millions of KT customers’ personal data had been leaked. 

The incident came to light when the Incheon Metropolitan Police Agency announced on Thursday it had arrested three suspects that day for allegedly hacking into the company’s website and stealing data of some 12 million clients of the mobile carrier.

The hacking attacks on the KT website allegedly took place over the course of one year starting last February, gathering up to 300,000 pieces of information in a given day.

“Those who are involved in the incident will be punished after a thorough investigation,’’ said Hwang, adding that the company will go back to the basics in a bid to regain public trust.

In related development, South Korea’s Telecom Ministry launched on Friday an investigation into the hacking incident at KT.

The ministry ordered for KT to provide the victims with details and background information about the incident and establish a system on its website to allow users to check if their information was leaked.

The ministry said it will operate an around-the-clock service center to receive reports on damages incurred from the leakage and warned users to be wary of calls and text messages from people claiming to be KT staff.

It added that its investigation showed that the security systems of SK Telecom and LG Uplus, the country’s two other major mobile carriers, were not found to have weaknesses similar to KT’s.

In 2012, the personal information of about 8.7 million mobile phone subscribers was stolen from KT by hackers, who sold the information to telemarketers who contacted customers whose contracts were nearing expiration or considered likely to change subscription plans.

The police said it plans to summon security specialists from KT next week for further investigations into the incident.

By Seo Jee-yeon and news reports
(jyseo@heraldcorp.com)