14-05-2025
SK Telecom completes USIM protection service for all users
SK Telecom said Wednesday that all 25 million of its users have signed up for the company's USIM Protection Service following a major data breach, including those using international roaming.
'Since the USIM protection service for overseas users began on May 12, we have completed the enrollment of all users by this morning. Essentially, all customers have now been covered,' said Ryu Jung-hwan, head of the network infrastructure center at SK Telecom, during a press briefing on Wednesday.
The company confirmed that the service has also been applied to all customers currently staying abroad.
Following one of the worst hacking incidents in its history, SK Telecom has scrambled to respond, including enrolling all users to its USIM protection service. The company asserts that the protection service effectively blocks the use of illegally cloned USIM cards on other devices, providing the same level of protection as physically replacing the USIM.
Previously, international roaming users were unable to join the protection system, but SK Telecom has since this Monday upgraded it to include them.
SK Telecom, the country's largest mobile carrier that nearly half of Korea's population uses, disclosed that it had suffered a cyberattack and subsequent data breach of customer's USIM data on April 18.
The data breach, caused by a malware attack inside a key internal system called the Home Subscriber Server, resulted in the leak of about 9.7 gigabytes of data. As of now, the exact cause and the identity of the attacker have not been officially confirmed.
The mobile carrier has also offered users the option to switch their USIM cards for free since April 28, but the swap process has been hampered by overwhelming demand and a supply crunch. According to the firm, some 16.9 million users have switched their USIM cards as of Wednesday.
SK Telecom said it plans to secure around 5 million additional USIM cards this month and another 5 million in June, vowing to speed up the replacement process.
To ease public concern, the company on Sunday introduced the new USIM reset solution that allows subscribers to update specific user identification from USIM chips without the need to physically replace the chip.
At the briefing, SK Telecom also said the USIM card replacement service at airports will end after Thursday, as not any people are using the service there. 'The staff stationed at the airport will be reassigned to our 2,600 T World Stores nationwide to accelerate USIM replacement services (at the stores),' said Lim Bong-ho, head of mobile network operator business.
From as early as next week, the company will also launch on-site USIM replacement or reset services for customers living in remote or island regions. The service will also be expanded to vulnerable groups, including older adults who have difficulties with technology.
