At first, KT explained that the Internet failure that occurred in the morning of the 25th was caused by a 'DDoS attack', a distributed service attack, but two hours later, in the afternoon, it corrected its position as a failure due to a network path setting error.

In the second notice, KT said, "Initially, it was assumed that it was DDoS due to traffic overload, but after a close inspection, we identified a network path setting error as the cause."

The Ministry of Science and ICT announced that it is conducting an in-depth investigation into KT's wired and wireless Internet failures that occurred for about 40 minutes from 11:20 am.

The Ministry of Science and ICT explained that according to the information communication accident risk management manual, the information communication accident crisis warning 'caution' was issued at 11:56 am.

The Ministry of Science and ICT has also established the 'Broadcasting Communication Disaster Response Situation Room' with the Information Security Network Policy Officer as the head of the situation office to check whether KT services are restored.