SK Telecom suspends new subscriber sign-ups amid data breach response

SK Telecom Co., South Korea’s leading wireless services provider, suspended new subscriber sign-ups nationwide Monday as part of its response to a recent data breach involving the company’s network.

The suspension came as the company focused on replacing universal subscriber identity module (USIM) chips for mobile phones after detecting a cyberattack on April 18, which indicated a large-scale leak of customer USIM data.

Last week, the government ordered SK Telecom to halt new sign-ups until the company addresses the ongoing shortage of USIM cards stemming from the breach.

SK Telecom has offered free USIM replacements to all 25 million of its subscribers, including 2 million budget phone users, in an effort to prevent potential damage. However the replacement process has slowed due to limited inventory.

A company official said about 1 million subscribers have already replaced their USIMs, while another 7.7 million have registered for replacements.

The company also introduced a USIM Protection Service, which it claims provides a comparable level of security against illegal financial activities as a physical USIM replacement.

In addition, SK Telecom has begun automatically enrolling digitally vulnerable users into the USIM Protection Service.

To support international travelers, the company has set up temporary booths at Incheon International Airport, west of Seoul, for on-site USIM replacements.

As of 9 a.m. Monday, 22.18 million people had signed up for the protection service, according to the company.

The official said the company has not yet identified any cases of financial damage resulting from the leaked data.

Meanwhile, as of noon Monday, more than 1,000 introductory posts had been uploaded to a Naver online forum titled “SK Telecom Personal Information Leak Class Action Cafe.”

The forum’s membership exceeded 75,000, with over 600 users expressing their intent to join legal action through their posts.