Massive SK Telecom SIM Card Data Breach Raises Security Concerns

On April 26, 2025, SK Telecom, South Korea's largest mobile carrier, faced a major security breach involving the leakage of SIM card issuance data. Personal information, including phone numbers, device details, and subscription histories, was reportedly compromised. The incident is believed to have affected thousands of customers, sparking widespread concern over telecom data security in South Korea.

According to initial reports, the breach originated from an unauthorized access to the SIM card management system. Authorities are investigating whether it resulted from internal negligence, external hacking, or a combination of both. SK Telecom has issued an apology and promised full cooperation with law enforcement, while offering affected customers free credit monitoring and SIM reissuance services.

Experts warn that leaked SIM information could lead to serious risks such as SIM swapping attacks, identity theft, and unauthorized access to financial accounts. Government agencies have urged users to immediately verify their mobile account security settings and enable additional authentication measures.

This incident has reignited public debate about the adequacy of cybersecurity measures among major telecom companies and the need for stronger regulatory oversight.