- Company
- SK Telecom
- Regulator or court
- Personal Information Protection Commission (PIPC)
- Law
- Personal Information Protection Act
- Status
- Under appeal (SK Telecom sued in the Seoul Administrative Court in January 2026)
What happened
Hackers got into SK Telecom's systems and stole SIM card (USIM) data affecting tens of millions of mobile subscribers; the intrusion reportedly began in 2022 but was only reported in April 2025. Korea's privacy regulator found weak access controls, unencrypted SIM authentication keys and late notice to customers, and treated it as a 'very serious' violation. At the time it was the largest fine under Korea's revised privacy law.
Sources
Light Reading – record fine on SKTLight Reading – SKT challenges fine in courtSK Telecom Form 20-F (FY2025)Summary in our own words. General information, not legal advice.