SK Telecom Responds to Data Breach Affecting SIM Information

Seoul, South Korea - SK Telecom has increased its capacity for SIM protection services following a cybersecurity incident that potentially compromised customer SIM card information, the telecommunications provider announced on Tuesday.

According to company statements, at 11:40 p.m. on April 19, the company detected malicious code in its systems that may have exposed subscriber SIM card data. 

SK Telecom said personal identification information, including names, addresses, and resident registration numbers, was not affected.

SK Telecom reported that as of Tuesday afternoon, more than 9.5 million subscribers had enrolled in the SIM protection service, and enrollment is expected to exceed 10 million by the end of the day.

The telecommunications firm has implemented three response measures: enhanced fraud detection monitoring, SIM protection services, and replacement SIM cards.

SK Telecom announced that it has increased processing capacity for the protection service by 50% starting April 28. 

The system verifies both SIM information and device data to block unauthorized access when providing telecommunications services.

The company began offering free SIM card replacements at its 2,600 retail locations nationwide on April 28. 

SK Telecom said it currently holds 1 million replacement SIMs in inventory and plans to secure an additional 5 million by late May.

Customer demand has led to long wait times at retail locations. 

The company implemented an online reservation system that received 3.82 million replacement requests on its first day of operation.

SK Telecom acknowledged that current SIM protection services do not function during international roaming. 

The company said system upgrades enabling protected roaming services are expected by mid-May.

The Korea Internet & Security Agency is investigating the incident. 

According to SK Telecom, no secondary damages related to the breach had been reported as of Wednesday.