SK Telecom says that a recently disclosed cybersecurity incident in April, first occurred all the way back in 2022, ultimately exposing the USIM data of 27 million subscribers. SK Telecom is the largest mobile network operator in South Korea, holding roughly half of the national market. On April 19, 2025, the company detected malware on its networks and responded by isolating the equipment suspected of being hacked. This breach allowed attackers to steal data that included IMSI, USIM authenticat...