South Korean telecom giant SK Telecom has confirmed a suspected leak of user USIM (Universal Subscriber Identity Module) information following a hacking attack. The company has reported the breach to the relevant authorities and is cooperating with an ongoing investigation to determine the full extent of the incident.
What is USIM and What Data Was Affected?
The USIM chip is a critical part of the mobile network, used to assign phone numbers to mobile users. SK Telecom emphasized that the leaked data does not include sensitive personal information such as resident registration numbers or payment details. No confirmed cases of misuse have been reported so far. But there are concerns that the situation could escalate depending on the results of the investigation.
When Did the Breach Occur?
The breach was first detected around 11 p.m. on April 19, when signs of malicious code targeting USIM-related systems were identified. In response, SK Telecom took immediate action to remove the malware and isolate the affected devices to prevent further damage.
Actions Taken by SK Telecom and Authorities
SK Telecom reported the incident to the Korea Internet & Security Agency (KISA) the day after the breach was detected. They also notified the Personal Information Protection Commission (PIPC) on April 22. The company is fully cooperating with authorities to investigate the breach and determine the full scope of the attack.
Telecommunications regulators, including the Ministry of Science and ICT, are also planning to conduct an on-site inspection at the company’s headquarters in Seoul.
Ongoing Investigation and Lack of Details
While SK Telecom has acknowledged the breach, the company has yet to disclose the full scale of the leak. The company said,
“A forensic investigation is underway, but due to the nature of cyberattacks, it’s difficult to determine the full extent of the leak in a short time.”
They have assured customers that it will provide further details as the investigation progresses. For now, they are urging users to remain vigilant and stay informed as more information becomes available.