Major South Korean telecommunications provider SK Telecom was disclosed by the country's Ministry of Science and ICT to have had almost 26.69 million units of international mobile subscriber identity stolen following a data breach initially reported last month, according to The Korean Herald.
Such a figure, which exceeds the firm's 25 million subscribers, is composed of USIMs that have been installed across various internet-connected devices, said officials. Additional findings also revealed that SK Telecom had almost two dozen servers compromised with 25 different malware types, with the first malicious payload having been deployed almost three years ago. While no SK Telecom data from Dec. 2, 2024 to Apr. 24, 2025 has been exposed, data leakage from June 15, 2022 to Dec. 2, 2024 remains uncertain due to the absence of firewall log history, officials added. "Given the types of malware and the methods used in this attack, it is clear that a far more sophisticated level of analysis and efforts are needed compared to what we've seen before," said South Korean Office of Network Policy Deputy Minister Ryu Je-myung.
Such a figure, which exceeds the firm's 25 million subscribers, is composed of USIMs that have been installed across various internet-connected devices, said officials. Additional findings also revealed that SK Telecom had almost two dozen servers compromised with 25 different malware types, with the first malicious payload having been deployed almost three years ago. While no SK Telecom data from Dec. 2, 2024 to Apr. 24, 2025 has been exposed, data leakage from June 15, 2022 to Dec. 2, 2024 remains uncertain due to the absence of firewall log history, officials added. "Given the types of malware and the methods used in this attack, it is clear that a far more sophisticated level of analysis and efforts are needed compared to what we've seen before," said South Korean Office of Network Policy Deputy Minister Ryu Je-myung.
