News and Analysis

SK Telecom has disclosed that a cybersecurity incident, exposing USIM data of 27 million subscribers, first occurred in 2022. Detected only in April 2025, the breach allowed hackers to steal sensitive data, thereby risking SIM-swapping attacks. As a result, SK Telecom issued SIM replacements for all subscribers while enhancing security. Recent findings revealed that the malware breach, involving multiple malware types across compromised servers, was far larger than initially estimated. The company vowed to fully assume responsibility for any potential damage to its subscribers.