SKT freezes new sign-ups, toughens consumer protection amid hacking fallout
SK Telecom said Friday it will suspend new subscriber sign-ups at its retail stores starting from Monday, to expedite USIM card replacements and to enhance customer protection in the fallout of a massive data leak from a recent hacking incident.
In a press briefing at the company's headquarters in downtown Seoul on Friday, CEO Ryu Young-sang announced that all 2,600 T World stores nationwide will halt receiving new subscriptions so the company can focus on replacing compromised USIM cards.
It will also stop mobile number portability services, which allows users to switch mobile network providers while retaining their phone number, until the USIM shortage eases.
Additionally, SK Telecom said it will compensate for losses incurred by the T World stores during this replacement period.
As for the detailed compensation plan, Ryu said it will be implemented after consulting with dealers. 'When looking at the distribution network, 350 of the 2,600 T World stores are directly operated by SK Telecom, and the rest are authorized dealerships. They are also small and-medium-sized enterprises, so asking them to stop taking new subscriptions could be a huge loss,' said Ryu.
However, the latest service halt does not extend to third-party retailers and online distributors, which are not under direct contract with the company.
The latest action is in response to the government's guidance issued the previous day, instructing SK Telecom to suspend new subscriptions until it resolves the USIM shortages for existing users and implement stronger corrective actions in response to the data breach.
SK Telecom, the country's largest mobile carrier with 25 million subscribers, serving nearly half of Korea's population, disclosed that it had experienced a cyberattack and subsequent data breach of customers' USIM data on April 18.
In response, the telecom giant said it removed the malware, isolated affected servers and enhanced security measures.
The company began offering free USIM chip replacements to all users on April 28, but it has been challenged due to overwhelming demand and a supply crunch, causing long lines at retail stores and system outages on its online reservation site due to high traffic.
The company has about 1 million USIM cards in stock, with plans to secure around an additional 5 million this month and another 5 million in June.
Amid the slow USIM swap rollout, the company said it will automatically enroll all customers into its USIM Protection Service without requiring a separate application.
The company asserts that the USIM Protection Service effectively blocks the use of illegally cloned USIM cards on other devices, providing the same level of protection as physically replacing the USIM.
As of Friday, 14.42 million people had joined the protection service, leaving out some 8.5 million others. The system can handle up to 1.2 million enrollments per day. The company plans to complete the process by May 14, with priority given to subscribers aged 75 or older and those with disabilities.
Following the hacking incident, SK Telecom is experiencing a massive user exodus to its main rivals, KT and LG Uplus.
According to the Korea Telecommunications Operators Association on Friday, more than 237,000 customers had switched from SK Telecom to other carriers, including KT and LG Uplus, in April alone, an 87 percent increase from March.
Amid growing calls to waive early termination fees for users, Ryu said the issue is still under review. 'The penalty fee is such a critical matter that the CEO cannot unilaterally decide, but must be approved by the board,' he said. 'We plan to have a board of directors discussion as soon as the internal legal review is completed.'
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Korea Herald
26-05-2025
- Korea Herald
Investigation into SK Telecom data breach expands to KT, LG Uplus: sources
A joint government-private investigation team looking into SK Telecom Co.'s recent large-scale data breach has extended its probe to the servers of two other major mobile carriers, KT Corp. and LG Uplus Corp., but found no signs they have been compromised, industry sources said Monday. Initially, the team had asked local telecommunications and platform companies to conduct their own cybersecurity inspections. However, the approach was revised last week amid growing concerns that hackers using BPFDoor malware variants may have also targeted other South Korean mobile carriers, according to the sources. Following the expanded investigation, no traces of hacking activity have yet been found on the servers of KT or LG Uplus, they added. In a media briefing last week, the investigation team revealed interim findings indicating that 25 malware variants had been discovered on 23 servers belonging to SK Telecom. These included 24 variants of the BPFDoor malware and one variant of WebCell. Two of the affected servers had been used as temporary storage for personal data, such as names, birthdates, phone numbers and email addresses, as well as international mobile equipment identity data. The IMEI is a unique identifier for each device on a network and could potentially be exploited in financial transactions. SK Telecom discovered the breach April 18. (Yonhap)
Korea Herald
21-05-2025
- Korea Herald
[Editorial] Hole in cybersecurity
SK Telecom breach dates back 3 years; Malware indicates China-based hacking The nation was jolted by interim probe findings that personal information and universal subscriber identity module or USIM data of practically all subscribers of SK Telecom may have been leaked by hackers. The cyberattack dated back about three years and turned out to be much more extensive than revealed in the initial briefing, according to the second briefing Monday by a joint investigation team of the Ministry of Science and ICT and the Korea Internet & Security Agency. SK Telecom discovered the breach about a month ago, on April 18. Leaked USIM data amounted to 9.82 gigabytes. which equates to roughly 26.9 million units of international mobile subscriber identity or IMSI numbers. This means that the USIM data of practically all SK Telecom subscribers has been leaked. Currently, it has 25 million subscribers, including 2 million budget phone users. A total of 23 SK Telecom servers were found to be compromised by malware, up from the five disclosed in the previous briefing held on April 29. The number of malware variants found to have infected the servers increased from four to 25. Among the affected servers, two had been used as temporary storage for personal data, such as names, birthdates, phone numbers and email addresses, as well as data on international mobile equipment identity or IMEI, a serial number assigned to every mobile phone. The possibility of financial fraud and other forms of secondary damage from copy phones has gone up. Investigators found that hackers planted malware on June 15, 2022. It is shocking that not only the telecom carrier but also the government and private cybersecurity firms had remained in the dark about the malware's infiltration for about three years. There is another problem. How much damage the cyberattack will cause down the road is anyone's guess. SK Telecom reportedly keeps log data for the last four or five months. So, no log data is available for the period from June 15, 2022, when malware was first planted, to Dec. 2, 2024. Fortunately, no evidence was found showing any data leakage between Dec. 3, last year and April 24 of this year, but investigators could not confirm whether any leaks occurred during the period for which log data is not available. It is worth noting that 24 of the 25 malware variants detected this time were found to be BPFDoor, a backdoor reportedly used by China-based hackers to attack Middle Eastern and Asian telecom companies in recent years. Experts warn that this malware could be used for a cyberattack on the communication infrastructure of a country. Given that data on all SK Telecom subscribers may have been leaked for as long as three years, the breach is not likely to emerge as a simple hacking case. It is uncertain whether the incident was an organized cyberattack to cripple the communication system of a country rather than an attempt to steal money. Considering the cyber intrusion was not detected for so long, anybody can guess a similar thing may be happening at other communication networks or major institutions. Communication infrastructure is one of the cruxes of state administration. Cyberattacks could paralyze it secretly, plunging a nation into chaos. The SK Telecom breach reconfirms how vulnerable South Korea has become to such vital attacks. SK Telecom bears the primary responsibility for protecting its system from hacks, but the government needs to check the nation's cybersecurity this time. Also, the National Assembly should do its part to help telecom carriers fend off cyber infiltrations from abroad. One of the laws that it needs to revise is its espionage law, which only punishes spying activities done for North Korea. Recently, two Chinese nationals were caught photographing fighter jets near air bases in South Korea but released after telling police that photographing was their hobby. Police say there was no evidence that they did so for North Korea. China or the US would likely respond quite differently. For a nation to keep its sovereignty, security must be tight, cyber or not.
Korea Herald
21-05-2025
- Korea Herald
Who hacked S. Korea's largest telecom, and why? Growing concerns the SKT data breach wasn't just about money
Some suspect a sophisticated Chinese hacking group may be behind the attack, raising potential alarms over cyber security Nearly three years before South Korea's largest telecom provider knew anything was wrong, hackers had already broken into SK Telecom's internal systems. This detail emerged from a briefing this Monday by the government's public-private joint investigation team, which is probing one of the country's most serious cybersecurity breaches in recent memory. The attackers first embedded malware on June 15, 2022, according to the investigation. That software remained hidden until last month, when over 9 gigabytes of sensitive SIM-related data tied to approximately 25 million subscribers, including customers of SKT's budget MVNO carriers, was suddenly exfiltrated. Among the leaked data were 21 types of subscriber-related information, including identification numbers and SIM authentication credentials. What hasn't been confirmed, however, is whether call records or other highly sensitive personal communications data were taken. SK Telecom has said its call detail records (CDRs) are encrypted, but encryption alone may not be enough, warns Professor Kim Seung-joo of Korea University's Graduate School of Information Security. 'Even encrypted data is vulnerable if the keys aren't securely managed,' he said in a separate media interview on Tuesday. 'The same thing happened to nine US telecoms last year.' CDRs are highly valuable in state-backed cyber operations. Unlike credit card data, they reveal patterns of communication and movement, making them ideal for tracking public officials and institutions, he explained. The malware discovered on SK Telecom's servers included BPFdoor, a backdoor tool also used by Salt Typhoon, the Chinese-linked group behind the attacks on AT&T, Verizon and T-Mobile. South Korean investigators have not confirmed the attribution, but suspicion is growing. Professor Lim Jong-in, a cyber defense expert at Korea University, told local radio on Wednesday morning that he suspects the Chinese hacking group Red Mansion may be behind the intrusion. They are known for APT-style cyberattacks -- operations that are typically slow-moving, well-funded and thus conducted by nation-state actors rather than ordinary cybercriminals. APT stands for Advanced Persistent Threat. 'Their yearslong persistence and stealth tell you this wasn't just about stealing data for profit,' said Professor Yum Heung-yeol, another cybersecurity scholar at Soonchunhyang University, according to a local media report on Wednesday. 'To compromise a core telecom operator without any spies or insider cooperation is not something amateur hackers can do.' So far, no customers have reported cloned phones, suspicious charges or extortion attempts. That silence and the long-term nature of the breach, the experts have all said, makes financial motives unlikely. 'We are looking into multiple possibilities, including whether the attack was to steal data or to establish long-term access to deeper systems,' said Ryu Jae-myeong, director-general of network policy at the ICT Ministry involved in the joint investigation team.
