South Korean telecommunications operator KT suffered a nationwide network outage earlier this week, affecting its telephone and wireless services including phone calls, internet, and other services.
The suspected distributed denial-of-service (DDoS) attack crippled the network for almost an hour. Customers using the telco's network were unable to access the internet for around 40 minutes at around 11am on Monday. Since then, general access to the Internet has been restored for KT users in most parts of the country.
To investigate the matter, a team of security experts from the Seoul cyber department was dispatched to KT's headquarters in Seongnam, Gyeonggi Province, just south of Seoul. Later in the day, KT restated that the outage appeared to have been caused by large-scale DDoS attacks. The firm said it is still looking for the culprits behind the DDoS and will continue to analyze the extent of the damage.
“The telco's network was shut down due to a large-scale DDoS attack. During the outage, the company's crisis management team was working to quickly restore the network back to normal. KT is yet to figure out the extent of the damage or who was behind the DDoS attack,” KT spokesperson stated.
The Ministry of Science and ICT said they are keeping a close eye on the matter in collaboration with KT. However, the ministry did not confirm that the network failure was caused by a DDoS attack, but it said the other major telcos SK Telecom and LG Uplus were not affected.
Despite not being victims of the DDoS attack, users of the services of SK Telecom and LG Uplus raised complaints on social media regarding telcos network outages. Spokespersons for these telcos said the network outages were due to a sudden surge in traffic from KT users switching their services due to KT’s internet outage. Both SK Telecom and LG Uplus representatives said they would be monitoring the situation closely.
According to the Science and ICT Ministry data, around 16.3 million people are dependent on KT for internet service as of March 2021. The last time KT suffered a network outage was in 2018 when a fire broke at its Ahyeon branch in central Seoul. The fire caused internet and phone service disruptions in nearby areas, including the Seoul districts of Jung-gu, Yongsan-gu, and Seodaemun-gu.
