Key facts
- KT Corp. was fined 53.9 billion won (US$37.4 million) by South Korea's privacy watchdog.
- The fine is due to a data breach affecting 16,647 users.
- The breach occurred via unauthorized mobile base stations accessing KT's wireless network.
South Korea's privacy watchdog has fined wireless carrier KT Corp. 53.9 billion won (US$37.4 million) over a major data breach affecting over 16,000 users. The breach occurred through unauthorized mobile base stations, leading to losses for victims.

The substantial fine and corrective measures highlight the critical need for robust cybersecurity in telecommunications, impacting user trust and potentially influencing regulatory approaches to data protection in South Korea.
South Korea's privacy watchdog has imposed a significant fine of 53.9 billion won (US$37.4 million) on wireless carrier KT Corp. following a major data breach. The Personal Information Protection Commission ordered the company to implement corrective measures after the breach compromised the data of over 16,000 users through unauthorized mobile base stations.
The breach, which was first reported by KT in September, involved the theft of phone numbers and mobile device identification numbers belonging to 16,647 users. Malicious actors exploited this information to conduct unauthorized transactions, leading to a total loss of 240 million won for 368 victims. The watchdog noted that the unauthorized access to KT's wireless network occurred between October 8, 2024, and September 5, 2025, with the company only becoming aware of the incident after a user complaint.
In response, the commission has mandated KT to strengthen its security measures for wireless network equipment and its overall personal information protection protocols.