The National Intelligence Service (NIS) recently identified a serious security issue involving some KT smartphones where SMS encryption was found to be disabled. This discovery was deemed a significant national cybersecurity threat, leading the NIS to officially notify KT and the Ministry of Science and ICT. According to data obtained by National Assembly member Choi Min-hee, the NIS investigated a tip-off indicating potential decryption of SMS messages on certain KT smartphones. They confirmed a vulnerability that could decrypt messages on intermediary servers, as these devices were not protected by end-to-end encryption, contrary to international recommendations that prevent server-side decryption.
KT is under further investigation to determine if the same vulnerability affects its entire network, beyond just certain smartphone models. Previously, KT experienced a micro-payment hacking case where hackers reportedly intercepted SMS and ARS authentication information.
Moreover, KT faced another cybersecurity issue with a BPFdoor malware infection discovered in March of last year, but only confirmed in the following April. This malware issue was not publicly disclosed at the time, leading to accusations of a cover-up by KT. Out of 43 infected servers, some stored subscribers’ personal information, raising questions about data safety and transparency.
KT defended its actions by stating that no direct damage was found from the malware infection, and it differentiated the timing of its response from reports by the security company Trend Micro. However, the investigation continues to understand the relationship between these cybersecurity issues and any potential data breaches. Government and private sector teams are working to uncover the full extent of any information leaks or damages, while Assembly member Choi Min-hee vows to hold KT accountable for its handling of the incidents.