At the same time, in a large PC café located downtown.
A group of high school students, their uniform ties loosened, were engrossed in an online game, making a ruckus.
"Hey! Get your aim right. We're taking that bastard down this time."
"Ah, damn it. I got hit by a stun!"
"Watch properly and shoot!"
Choi Jong-tae, who had placed his school bag beside the monitor, focused on the screen as he worked the keyboard and mouse with both hands.
"Hurry, hurry…."
With the Banggutaengi's barrel raised high, the power gauge filled up red.
After checking the firing angle one last time, Choi Jong-tae lightly licked his lips and pressed the fire button.
Click, click.
"What the—why isn't it firing?"
Choi Jong-tae kept clicking the mouse repeatedly, but there was no response at all.
Even the game screen on the monitor had frozen, as if time itself had stopped.
"Ah, damn it!"
At the same moment Choi Jong-tae threw his mouse, irritated voices burst out from all around.
"What the—lag?"
"This crazy luck-based trash game is acting up again."
"Hey, hey, the guys over there are saying theirs isn't working either."
"Ugh, what the hell is this mess? Go call the owner."
As the students playing the game grumbled and vented their frustration, a female college student—who had been in the middle of course registration before getting abruptly disconnected—stomped her feet in panic.
"Ah, no! Today's the last day for course registration!"
But no matter how many times she clicked refresh, only the message [Page not found] appeared, and she couldn't access the university website at all.
"Man, it was just getting fun."
"Hey! Let's go somewhere else."
Having completely lost the mood while gaming, Choi Jong-tae grabbed his school bag and stood up along with his friends.
"No, wait a moment, customers!"
Not only the high school students but even the other customers sitting in the corners of the PC café grumbled as they all filed out, leaving the place empty in an instant.
"What the hell is going on all of a sudden? Why did the internet just cut off like this?!"
The owner, flustered, hurriedly grabbed the phone and called the internet service center.
But only the automated waiting message played, and no matter how long he waited, he couldn't get through to an operator. Furious, he slammed the receiver down and shouted.
"The internet's completely down, so why aren't they answering the phone too?!"
Even though it was the weekend—when the place should have been packed—the owner blankly looked around the now-empty PC café before dropping his forehead onto the counter.
"Damn it… today's business is completely ruined."
***
3:20 PM, KT Hyehwa Telephone Exchange in Jongno District, Seoul.
Tall black server racks filled the server room in the building's basement from wall to wall.
It was a place where LED lights blinked in steady rhythms, and large cooling systems ran 24 hours a day to maintain a constant temperature.
But instead of the usual hum of cooling fans dissipating the servers' heat, the space was now filled with the frantic footsteps of employees rushing about and urgent shouts.
"Manager! Traffic exceeding 50,000 calls is pouring in all at once."
At the subordinate's scream-like shout, Manager Woo Chang-gon—wearing a work jumper with the KT logo—hurried over to the monitor.
The traffic graph, which should normally have drawn a smooth curve, instead shot straight up, as though it might burst right through the screen. Without realizing it, he cursed.
"Damn it!"
"Ma-Manager. As the traffic is surging, the DNS server has completely gone down. What should we do?"
At the trembling report from his subordinate, whose face had turned pale white, Manager Woo Chang-gon forced himself to hold onto his fading composure.
Then, clenching his teeth tightly, he issued orders to the employees inside the server room.
"The DNS server is overloaded and can't resolve IP addresses. That's why domain access is completely blocked, and the entire internet is down. Hurry—bring the backup servers online and distribute the traffic as much as possible!"
The Hyehwa Telephone Exchange was a communications hub that transmitted and relayed voice and internet signals both domestically and internationally.
Simply put, when a user enters a web address into the browser, the DNS servers installed at the Hyehwa Exchange convert it into an IP address and connect it to the corresponding site, whether domestic or overseas.
As an international gateway linking the domestic internet network with the rest of the world, it was naturally classified as a critical national infrastructure facility and was strictly managed.
With a problem occurring in a place that could be considered the very heart of the country's internet network, this was no ordinary situation.
As if proving that point, Manager Woo Chang-gon felt his mouth go dry over and over again, while the other employees, drenched in sweat, hammered at their keyboards with trembling hands.
At that moment, one subordinate looked at Manager Woo Chang-gon with a despairing expression and spoke.
"Our servers went down, and the traffic redirected from them is causing the backup servers to fail one after another in a chain reaction!"
"This is driving me insane."
Manager Woo Chang-gon lifted his head and looked at the large situation display installed on one wall.
On the screen, not only the Hyehwa Telephone Exchange but even the backup servers— which should have been marked in green—were now lit up in red.
At first, only a few had turned red, but as he watched the lights spread faster and faster, he felt a growing sense of fear.
It was as if he were witnessing an invisible, deadly poison spreading violently in all directions through the veins of a network.
"Traffic has exceeded 64,000 calls!"
At the employee's scream-like shout, Manager Woo Chang-gon squeezed his eyes shut.
The figures had already far exceeded not only normal levels but even the maximum capacity the Hyehwa Exchange's DNS servers could handle.
"There's also a traffic attack hitting the main servers of the internet service providers!"
Another employee, clutching a receiver, urgently spoke up.
"Not just regular companies—even banks and government institutions have completely lost internet connectivity. What should we do?"
Amid the continuous stream of reports, Manager Woo Chang-gon stared blankly at the major nodes, which had now turned completely red.
If it were a virus, they might have found some way to stop it—but with traffic surging far beyond acceptable limits and bringing the servers down, there was nothing they could do.
"How on earth are we supposed to fix this…?!"
The fact that he could do nothing but stand by and watch as South Korea's internet network collapsed right before his eyes weighed heavily on Manager Woo Chang-gon.
***
[Starting around 3 p.m. today, an unprecedented incident has occurred in which the nationwide internet network has been completely paralysed.
As a result, various services—including internet banking, shopping malls, email, and reservation systems for railways, airlines, and express buses—have all been suspended, causing significant inconvenience to users.
KT stated this afternoon that as the DNS function at the internet network hub in Hyehwa-dong, Seoul, was disrupted, traffic was redirected to other DNS servers, such as the Guro hub. The resulting overload triggered a chain of failures, leading to a nationwide internet outage.
Backup systems are currently being activated, and recovery efforts are underway, but it is unclear how long it will take to restore normal operations....]
Director Choi Ho-geun, who had returned home from work and was playing with his children in the living room, stared blankly with his mouth open as he watched the breaking news on television.
"This is so out of the blue—what on earth is going on?"
The internet they had been using so conveniently until now had suddenly gone completely dead—it was something no one could have imagined.
"Ugh. Why did this have to happen today of all days?"
His wife, dressed to go out, came out of the bedroom while grumbling.
"What's wrong?"
"We decided to take a flight to Daegu for the Lunar New Year holiday since the highways would be heavily congested."
"Right."
"I was going to book the tickets today, but the internet suddenly cut off, so I couldn't. Seriously, I have the worst luck."
"The news is already making a big fuss about the internet outage."
Director Choi Ho-geun gestured toward the living room television with his chin as he spoke.
"Anyway, I'll step out for a bit, so keep an eye on the kids."
"Where are you going?"
"What choice do I have if the internet's down? I'll go to a travel agency on the main road and ask them to book it for me."
"Even if you go, it probably won't work."
"How would you know?"
His wife asked with a frown.
"I saw on the news—since the internet is down, not only flights but also train and express bus ticketing services aren't working. So going to a travel agency won't really help."
"This is a big problem. The Lunar New Year holiday is next week—what are we supposed to do?"
At that, Director Choi Ho-geun shrugged as if it couldn't be helped.
"If it doesn't work, I'll just drive down myself."
"It'll take almost seven or eight hours to get to Daegu—are you sure you'll be okay?"
"It's not like I've never driven during the holidays before. I'll be fine. If I get tired, I'll just stop by rest areas often and take it easy on the way down."
"If you say so…."
His wife let out a sigh and picked up her bag.
"Since I'm already dressed, I'll go to the market nearby and pick up some side dishes."
"Alright."
After his wife put on her shoes and left, Director Choi Ho-geun stroked his chin, watching the continuing news with a look of amazement.
"To think something like this would happen right after we finished accumulating internet security stocks on the chairman's orders…."
True to his nature as a stock trader, the first thing that came to mind as soon as he saw the news was security-related stocks.
He had a gut feeling that, with this incident driving a surge in interest in internet security, the prices of security stocks—which had not received much attention until now—would skyrocket.
"This is going to be a total jackpot."
The idea of personally driving down to his hometown during the Lunar New Year holiday had long since vanished from his mind.
Right now, all that filled Director Choi Ho-geun's thoughts was anticipation over how high the security stocks he had already scooped up in advance would soar.
***
[Page not found.]
The same error message was displayed on every monitor set up on the desk.
Seok-won leaned back in his cushioned chair as he looked at it and muttered.
"As expected, things have unfolded just as I knew they would."
Although someone had deliberately carried out a malicious attack, the incident was also somewhat predictable.
"If only they had prepared even a little for this kind of attack, the damage wouldn't have spread this far. Whether it's the government or corporations, they're now paying the price for pushing security aside just because it wasn't immediately visible and only cost money."
The cause of this situation was a worm virus that had infiltrated Microsoft's SQL Server, which had not been updated with the necessary security patches.