LEAD Investigation shows KT concealed malware infections security failures leading to hacking breach Yonhap News Agency

pAll HeadlinesppNorth KoreappSportsppTop NewsppMost ViewedppKorean Newspaper HeadlinesppToday in Korean HistoryppYonhap News SummaryppEditorials from Korean DailiesppURL is copiedppATTN UPDATES with more details in paras 1415 ADDS photopp SEOUL Nov 6 Yonhap KT Corp South Koreas secondlargest mobile carrier was found to have concealed critical malware infections and failed to report the security breaches that led to a recent hacking and data theft incident a governmentled investigation revealed Thursdaypp The joint governmentprivate investigation team which is examining KTs recent cyberattack linked to illegal micro base stations said the company learned between March and July of 2024 that 43 of its servers had been infected with socalled BPFDoor malware and other malicious code pp Despite detecting the infections which exposed customer data the company did not notify authorities and instead attempted to handle the issue internally according to the team pp BPFDoor malware enables remote attackers to bypass firewalls and maintain longterm access to compromised systems It was also used in a separate hacking case involving industry leader SK Telecom Co reported earlier this yearpp Investigators confirmed that the infected KT servers contained customers personal information including names phone numbers and email addresses as well as international mobile equipment identity IMEI datapp The team said it regards the concealment as being of grave concern and plans to work with relevant authorities to determine proper legal measuresppThis photo taken Nov 5 2025 shows a KT store in Seoul with a notice showing the mobile carriers plan to offer free USIM replacements to address customer data security concerns Yonhappppp The probe also revealed serious vulnerabilities in KTs femtocell management which allowed unauthorized devices to connect to the companys internal network pp A femtocell is a small lowpower cellular base station typically designed for use in homes or small businesses pp KTs femtocell management system was generally poor creating an environment in which unauthorized femtocells could easily access the companys internal network the team saidpp The investigation concluded that hackers controlling illegal femtocells were able to disable endtoend encryption allowing the interception of users payment authentication data pp The Ministry of Science and ICT said it will conduct a legal review to determine whether KTs actions were in breach of the law and constitute grounds for customer compensationpp The investigation was launched after 368 KT customers suffered financial losses totaling 240 million won US167000 in August through illegally operated micro base stationspp KT began offering free universal subscriber identity module USIM replacements to all customers Wednesday to address growing data security concern among userspp Officials added that KT has been referred to law enforcement authorities on suspicions of obstructing justice for allegedly providing false information and concealing evidence during the probe pp KT could also face a potential financial penalty from the Personal Information Protection Commission similar to the one imposed on SK Telecom for its own hacking incident earlier this year SK Telecom was fined 1347 billion won by the commission for a similar data breachppChoi Woohyuk head of network policy at the Ministry of Science and ICT speaks during a briefing at the government complex in Seoul on Nov 6 2025 regarding a governmentled investigation into a hacking incident involving mobile carrier KT Corp Yonhappppp odissyynacokrENDppAll NewsppNationalppNorth KoreappEconomyFinanceppBizppCultureKpopppSportsppImagesppVideosppTop NewsppMost Viewedpp Korean Newspaper HeadlinesppToday in Korean HistoryppYonhap News SummaryppEditorials from Korean DailiesppKorea in BriefppUseful LinksppWeatherppAdvertise with Yonhap News Agencyp