Korean telecom service store shut their doors due to a shortage of USIM chips!

 South Korea's major telecommunications provider, SK Telecom, announced that it would replace the USIM (Universal Subscriber Identity Module) cards of all users after a hacking attack led to the leakage of subscriber information. However, it was revealed that SK Telecom violated regulations that require reporting such incidents to authorities within 24 hours of recognizing the breach. It is said that it may take one or two months just to confirm the perpetrators and assess the full scale of the damage.

A bigger problem, however, is that when customers visit SK Telecom stores for the announced mass USIM replacement, there is a severe shortage of USIM stock, making smooth replacements difficult. SK Telecom said it first detected unauthorized movement of internal system data at 6:09 p.m. on April 18. Later that evening, at around 11:20 p.m., malware was found on the servers that handle USIM information, confirming a hacking attack. By 11:40 p.m. the following day, SKT confirmed that some USIM information had indeed been leaked.

Nevertheless, SKT only reported the incident to the Korea Internet & Security Agency (KISA) at 4:46 p.m. on April 20 — about 17 hours after initially detecting the breach, and approximately 40 hours after recognizing signs of hacking. Under South Korean law, information service providers must report data breaches to the Ministry of Science and ICT or KISA within 24 hours of discovery. Failure to comply can result in a fine of up to 30 million KRW (around $22,000 USD). SKT claimed there was no deliberate delay, explaining that time was needed to verify whether an external attack had actually occurred.

On April 24, speaking to reporters at the 2025 World IT Show, the Minister of Science and ICT stated:

"With the spread of AI technologies, the frequency of information breaches and the scale of cyberattacks are likely to increase. Companies must pay greater attention to cybersecurity."

Amid the hacking incident, user anxiety and inconvenience are growing. Although SKT announced it would replace all USIMs, the company, which has about 25 million subscribers, is struggling to meet the demand, causing fears among users to grow even further.

To prevent additional damage, SKT is offering customers a USIM Protection Service. This service blocks unauthorized attempts to access a subscriber’s information by cloning or stealing their USIM and trying to connect using another device. However, users must apply for the service through SKT’s website or app. Within just two days of the announcement, over one million customers had signed up for the service.

SKT also announced it would extend the USIM Protection Service to customers of 14 budget mobile carriers that share SKT’s network. Since the USIM information of these users is also stored on SKT’s servers, the company aims to prevent any potential harm. However, subscribing to the protection service requires users to cancel their international roaming services, which can be inconvenient. Roaming restrictions are imposed to prevent the abuse of USIM information overseas.

Lee Jong-hoon, head of SKT's Infrastructure Strategy Division, stated:

"We believe the enhanced FDA (Fraud Detection & Authentication) system and the USIM Protection Service are already as effective as replacing USIMs. Nevertheless, to alleviate customer anxiety, we have decided to replace the USIMs of all subscribers free of charge."

However, the reality on the ground is grim. Local SKT stores have run out of replacement USIM chips, and some stores, overwhelmed by the flood of customers and inquiries, have even suspended operations altogether.

One SKT store put up a notice saying it was temporarily closed because there were no USIM chips available for replacement."