SK Telecom cyberattack: Free SIM replacements for 25 million customers

South Korean mobile provider SK Telecom has announced free SIM card replacements to its 25 million mobile customers following a recent USIM data breach, but only 6 million cards are available through May. SK Telecom is the country's largest mobile network operator, serving roughly half of the domestic mobile phone market. On April 19, the company detected a malware running on its network that allowed threat actors to steal customers' Universal Subscriber Identity Module (USIM) data, typically including International Mobile Subscriber Identity (IMSI), Mobile Station ISDN Number (MSISDN), authentication keys, network usage data, and SMS or contacts if stored on the SIM. No customer names, other identification details, or financial information were exposed due to this incident. The main risk from this breach is the potential for threat actors to perform unauthorized number ports to cloned SIM cards, known as "SIM swapping." In an update published earlier today, SK Telecom assured cus ... Read full article.