"SKT USIM Hacking: Fear Leads to USIM Hoarding...Cash Withdrawals Not Possible"

"Do Not Succumb to Excessive Fear...
Start by Enrolling in the USIM Protection Service"
"The Most Realistic Threat Is Password Change"

Amid the so-called "USIM crisis" following the hacking incident at SK Telecom, Kim Seungjoo, a professor at Korea University's Graduate School of Information Security, stated, "There is no need to be overly fearful, as security measures for financial transactions such as digital certificates and OTPs are in place to protect us."

On April 29, during an appearance on CBS Radio's "Kim Hyun-jung's News Show," Professor Kim said, "It is clearly SK Telecom's fault for not taking preventive measures to avoid being hacked." However, he also pointed out, "But it is also a problem that excessive fear has led to a shortage of USIM cards."

On the 28th, when SK Telecom, which had its subscriber USIM information stolen, started a free USIM replacement service, citizens are receiving numbered tickets at an SKT agency in downtown Seoul to replace their USIM cards. Photo by Yonhap News

He continued, "The most fundamental solution is to replace the USIM card." He advised, "Since there is currently a shortage of USIM cards, domestic subscribers only need to sign up for the USIM Protection Service. This service allows the telecom provider to detect device changes and prevent the use of cloned phones." He emphasized, "There is no need to be excessively fearful. Domestic subscribers should enroll in the USIM Protection Service for now, and USIM replacements should be prioritized for those who urgently need to travel abroad. However, because of excessive fear, people are hoarding USIM cards, creating chaos."

He added, "However, there is a drawback to the USIM Protection Service. If you subscribe to this service, international roaming will be blocked. SK Telecom announced that by next month, it will update its system so that international roaming and the USIM Protection Service can coexist."

He explained, "What is possible through USIM chip hacking is the creation of a cloned phone using the duplicated USIM chip. If a cloned phone is made, calls and text messages intended for me could be received by the cloned phone." He further clarified, "However, the important point is that both devices cannot be connected at the same time. Therefore, the most realistic threat is that a hacker could use SMS authentication to change your password."

He also noted that concerns about the withdrawal of cash or virtual assets are unfounded. Professor Kim said, "Logging into internet banking or making a transfer requires a great deal of information. Even if a hacker intercepts SMS authentication and changes the password, they cannot make a transfer without the digital certificate password or OTP card information."