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. 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. As of today, SK Telecom is also offering free-of-charge SIM card replacements to 25 million mobile subscribers, including approximately 2 million using budget carriers, who are worried about the potential for SIM swapping attacks impacting them. In an update published earlier today, SK Telecom assured customers that such requests would be automatically detected and blocked by its Fraud Detection System (FDS) and SIM Protection Service, which have been enhanced to handle the elevated risk. Bill Toulas Bill Toulas is a tech writer and infosec news reporter with over a decade of experience working on various online publications, covering open-source, Linux, malware, data breach incidents, and hacks. However, the mobile carrier warns that due to a lack of inventory, they can only replace up to 6 million SIM cards through May 2025.
This Cyber News was published on www.bleepingcomputer.com. Publication date: Tue, 29 Apr 2025 16:50:15 +0000