USIM leak at SK Telecom drives customers to budget mobile carriers

Customers line up to replace USIM cards at an SK Telecom branch in Seoul, Monday. A notice on the door states that USIMs are currently out of stock. Yonhap

Customers are turning to budget mobile carriers as SK Telecom struggles to meet soaring universal subscriber identity module (USIM) replacement demand following its recent security breach, industry officials said Wednesday.

Sales of budget carriers' USIMs have spiked at retail outlets such as convenience stores, while bank-affiliated budget carriers are also experiencing an increase in users.

Convenience store chain CU reported that sales of budget USIMs from April 22 to Monday jumped 205.3 percent compared to the previous week. At 7-Eleven, sales rose by 180 percent week-on-week, while Emart24 saw an 84.2 percent increase. On Monday alone, GS25 recorded a 1,153 percent surge in budget USIM sales compared to a week ago.

"USIMs usually don’t experience sharp fluctuations in sales, so the sudden spike indicates strong customer demand," a CU official said. "We will increase order volumes as much as possible."

The disruption began on April 18, when SK Telecom discovered signs of a cyberattack and a large-scale leak of customers’ USIM data. In response, the company pledged swift action and launched a USIM replacement program.

However, with SK Telecom struggling to meet soaring USIM demand, public frustration is growing. Privacy concerns have encouraged many to consider switching to more affordable budget mobile plans.

With SK Telecom users increasingly fleeing from the mobile carrier, bank-backed budget mobile services are reaping unexpected benefits.

Budget mobile services backed by KB Kookmin and Woori Bank entered the market after the service was approved as a permissible ancillary business, but initially faced challenges in securing a customer base.

Industry officials say that new sign-ups for KB Kookmin Bank’s budget mobile brand, KB Liiv M, began rising after news of the SK Telecom hacking incident became public on April 22. The budget carrier currently maintains a customer base of around 430,000.

Woori Bank’s newly launched budget mobile brand, Woori WON Mobile, which debuted on April 18, has also reported increased customer interest. A company official noted a noticeable uptick in inquiries about USIM protection services and number porting starting last weekend.