On Wednesday, Choi Tae-won, Chairman of SK Group, publicly apologized for a significant data breach at SK Telecom, South Korea's largest mobile network operator. The breach, which has raised serious concerns among 23 million users, was linked to a malware attack. With the potential risk of personal and financial information being stolen, SK Telecom's $SKM customers quickly sought measures to protect their sensitive data, including replacing their universal subscriber identification modules (USIMs) at no additional cost.