<ul><li>SK Telecom, South Korea's largest wireless telecom company, reported that threat actors accessed customer Universal Subscriber Identity Module (USIM) info through a malware attack.</li><li>The company detected the infection on April 19, 2025, and promptly reported it to the Korea Internet & Security Agency (KISA), sanitized the impacted systems, and isolated the suspected hacking device.</li><li>No cases of misuse of the information have been confirmed to date, but SK Telecom has enhanced defensive measures, blocked illegal SIM card changes, and abnormal authentication attempts.</li><li>The company is offering impacted customers a free subscription to the 'SIM protection service' as an additional security measure.</li></ul>

Millions of SK Telecom customers are potentially at risk following USIM data compromise

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