Hackers access sensitive SIM card data at South Korea’s largest telecoms company www.bitdefender.com/en-us/blo…

Mobile network operator SK Telecom, which serves approximately 34 million subscribers in South Korea, has confirmed that it suffered a cyber attack earlier this month that saw malware infiltrate its internal systems, and access data related to customers' SIM cards. [T]he information identifying SIM cards is considered highly sensitive - as it could permit a determined criminal to hijack victims' phone numbers in a “SIM Swap” attack.

The breach occurred at around 11pm local time, on the night of Saturday 19 April 2025, in what is believed to have been an attack intentionally timed to exploit a day and time when there may be less staff monitoring in place.