What you need to know about SKT data breach

SK Telecom customers wait in line to switch their USIM cards at a branch in Seoul, Tuesday, after a hacking incident earlier this month. Yonhap

What happened?

On April 22, SK Telecom announced that it had detected a breach in its internal system on April 18. It was confirmed the following day the hacker stole USIM-related information using malicious code to attack the system.

How did SK Telecom notify the public about the hack?

On April 22, SK Telecom uploaded a press release on its official website and sent emails to reporters. The company also began sending text notifications to customers, but some had still not received them as of Wednesday. No notices in English have been issued so far, leaving non-Korean-speaking customers in the dark.

What is the current situation?

SK Telecom said Friday that it would provide free USIM card replacements, and that it currently had 1 million in stock. As of Tuesday, 280,000 customers had received new cards. The company plans to secure 5 million cards by May, though this still falls short of the amount needed, as SK Telecom has over 23 million customers.

SK Telecom is also offering a free USIM Protection Service, but it does not work for customers who are overseas and using roaming services. The company plans to enable this service for those on overseas roaming by mid-May. As of Wednesday, 10 million customers have signed up for the protection service.

What will SK Telecom do to address the problem?

The company announced that it plans to allow customers to switch their USIM software by mid-May. This update will offer the same benefits as replacing the USIM card. Customers will need to visit an SK Telecom store to complete the software switch.

What should you do?

You need to visit an SK Telecom branch in person to get your USIM card replaced. The 1 million cards currently available are being distributed to branches across the country over the course of several weeks, meaning there will be limited stock available each day.

You can start by signing up for the USIM Protection Service on the T World website, which is in Korean. Customers who are traveling abroad will be prioritized in securing new USIM cards, as they cannot sign up for the USIM Protection Service while using overseas roaming. Customers inside the country can join a waitlist to switch their USIM cards, but the signup page is in Korean.

In the meantime, customers who have been abroad since the hacking incident remain at risk, as they cannot physically replace their USIM cards or sign up for the USIM Protection Service while abroad.

An SK Telecom spokesperson said "The company is monitoring the situation for customers who are overseas."