![]() |
Photo = SK Telecom |
[Alpha Biz= Paul Lee] Seoul, April 24, 2025 — SK Telecom failed to report a recent hacking attack within the legally required 24-hour window, with new findings revealing the company became aware of the breach a day earlier than previously disclosed.
According to documents submitted by SK Telecom to Rep. Choi Soo-jin of the National Assembly’s Science, ICT, Broadcasting and Communications Committee, the company first detected unusual internal system data activity at 6:09 p.m. on April 18.
Later that evening, at 11:20 p.m., malicious code was identified, confirming a cyberattack. By 1:40 a.m. on April 19, the company began analyzing the scope of the data breach and, 22 hours later at approximately 11:40 p.m., confirmed that the hackers had accessed certain user SIM-related information via the malware.
Despite this early detection, SK Telecom reported the incident to the Korea Internet & Security Agency (KISA) only at 4:46 p.m. on April 20—over 45 hours after the initial signs of intrusion and more than 24 hours past the confirmation of the hack.
Under Korea’s Act on Promotion of Information and Communications Network Utilization and Information Protection, service providers are required to report security breaches within 24 hours of discovering them. KISA confirmed to Rep. Choi’s office that SK Telecom’s delay constituted a violation of this regulation.
In response, SK Telecom stated, “Due to the seriousness of the incident, we delayed the report in order to accurately confirm the cause and scope of the damage. The delay was not intentional.”
Alphabiz Reporter Paul Lee(hoondork1977@alphabiz.co.kr)