65. Theon Thirteen
Yoon Sung Soft.
After greeting between Major’s older sister and Yunseok’s older brother, the older sister sat down and said:
“I heard you found your brother.”
Yoon Seok-yi hyung said with a full smile on his face.
“Yes, it’s winter vacation, and Eunseong is staying at our house these days.”
“okay? Parents will love it.”
“sure. love it so much It’s almost as if you’ve been reborn.”
The older sister nodded her head with a happy expression, and Yoon Seok-yi hyung continued talking proudly.
“My father stopped drinking, and he is preparing the restaurant again, which he left off before. Now when you enter the house, it feels like a real home.”
Come to think of it, Yoon Suk-yi’s bedding was completely gone in the Yoon Sung Soft office.
Yoon Seok-yi hyung pointed at me and said.
“It’s all thanks to Jung-ho.”
At Yunseok-hyung’s words, the major older sister gave me a thumbs up and said,
“Awesome!”
“I was just lucky.”
At my words, Yoon Seok-yi hyung said.
“Aren’t you too humble?”
The older brother turned his head back to the older sister and continued speaking.
“There is a program to find a missing child created by Jeongho and Incheol, and through that program, we are currently preparing a contract with the Seoul Metropolitan Police Agency.”
“Five! okay? It’s really great. But who is Incheol? I think I’ve heard that name somewhere… .”
I said to my sister’s question.
“He’s my friend, and he’s crazy about computer programs.”
At my words, my older sister smirked, and I looked at Yoon-seok-hyung and said.
“Brother, could you please take a look at the major noona’s computer?”
While my sister took out her laptop from her bag and turned on the power, I explained her situation to Yoon Seok-yi.
When I finished my explanation, he said with a serious expression.
“Are you sure about that? It would be almost impossible to target a specific person and steal computer information… .”
In response to Yoon Seok-yi’s words, the major older sister added.
“Yeah, it’s Jeongho. Thanks for worrying about me, but I don’t think this is. I think I said something to Professor Park.”
The older sister continued speaking with a short sigh.
“And because you haven’t met David McLean, he didn’t look like someone who would do such a bad thing.”
It’s crazy and running around.
David, what a vicious bastard… .
I suppressed my frustration and persuaded my sister once again.
“Sister, please believe me just once. Unless it was written by the same person, it is impossible for the same sentence to appear from different papers to Toh.”
At my words, my sister gave a short sigh and handed her computer to Yun-seok-hyung.
“Is there a program here? It’s a program called McLean MathTech. Do you have a virus removal program that you sent me? What was that name?”
“V-Stop.”
“Yeah, right. When installing McLean MathTech, V-Stop gave me a warning once or twice.”
“Did the same warning pop up these days?”
“No, it was only the first time.”
After thinking for a moment at my sister’s answer, Yun-seok-hyung said to me.
“Jeongho, do you have a V-Stop record file that came into our server from your sister’s computer?”
I shook my head without saying a word, and Yoon Seok-yi hyung said.
“Well, there’s no way it’s still there. Hmm… How about this?”
The older sister asked Yoon-seok-yi hyung.
“Is that V-Stop record file important?”
“Yes, senior. The fact that the log file was created means that the malicious code was first discovered, and then part of the script that was identified as malicious code is left in the V-Stop log file.”
At his brother’s words, the older sister tapped her computer with her finger and said.
“Is that malware script not on my computer right now?”
“Yes, there will be. The moment the malicious code was installed as an executable, the source code script would have been automatically deleted. If it had stayed so far, V-Stop log files would keep coming into our servers.”
Major’s older sister nodded, but, judging from her older sister’s expression, it didn’t seem that Yun-seok understood hyung’s explanation properly.
Anyway, the bottom line is that you need the V-Stop log files that were deleted three months ago.
I said to Yunseok hyung.
“Brother, will you wait a minute?”
“… ?”
I opened a text file on my computer and started tapping on the keyboard.
After about 5 minutes, the contents of the deleted V-Stop record file were restored in the text file.
Seeing the restored contents, Yun-seok-hyung stuck out his tongue and said:
“what? Did you memorize all of this? Is this possible?”
I said with a slight smile.
“At that time, I looked at a lot of similar files, and I started to memorize them little by little.”
“No matter how many similar files you look at, it’s true. This is really great. haha!”
After checking the recovered log files, Yun Seok-yi’s older brother told the major’s sister.
“Major-senpai, do you use a program called LaTeX by any chance?”
LaTeX is an equation editor program, which is probably one of the programs that my major sister, who is a professor of mathematics, uses the most while writing a thesis.
My older sister nodded and answered yes, and Yoon Seok-yi opened her mouth with her eyes fixed on my monitor.
“Senior, I think Jungho is right.”
At the words of the older brother, the older sister said with a surprised expression.
“really? Are you sure? And how do you know that?”
“When the LaTeX program starts, it seems that the malicious code is activated as well. It’s probably monitoring the information being entered through the LaTeX Equation Editor?”
“Are you monitoring input? What information?”
“Wait.”
Seok-yi Yun brought a book and opened the ASCII table, and wrote down the formula on the paper, checking the monitor and ASCII table alternately.
After a while, the older brother who completed the formula opened his mouth.
“This formula is the trigger.”
“trigger?”
In the case of some malicious codes or viruses, an infected computer may show symptoms only when certain conditions are met, and these specific conditions are called triggers.
The famous Michelangelo virus a long time ago is a good example.
The computer infected with the Michelangelo virus works without any problem, and as soon as the internal clock of the infected computer indicates March 6, the virus is activated and begins to destroy information on the hard disk.
In other words, the date of March 6 is the trigger for the Michelangelo virus.
The formula Yoon Seok-yi hyung wrote on the paper.
That was the essence of Yoon-Schultz’s theory.
The expression of the major older sister who confirmed the formula hardened.
My sister said to me in a trembling voice.
“Jungho, this is… What do you mean?”
“Malicious code is planted on my sister’s computer, and this malicious code usually hides, and when the basic formula of Yoon-Schultz theory is entered through the LaTeX equation editor, it does something.”
“What are you doing?”
“I don’t know. However, under the circumstances, it seems that the document containing this formula is being sent to an external server.”
“If it’s an external server… Can you tell where it is?”
“I think David McLean sent it to where he wanted it to go, but I can’t tell from the V-Stop archives here alone.”
I turned my head to Yunseok hyung and said.
“Is there any way to know where this is being sent?”
Yoon Seok-yi hyung shook his head and said.
“It’s impossible. To know that, you need to know the source code script, and there is no way to find out unless the person who created the malicious code reveals it himself.”
A good idea suddenly came to mind.
ah… ! Why didn’t I think of this before?
I said to the major sister.
“sister! Do you have a CD or diskette with McLean MathTech installed?”
At my question, my sister opened her mouth with a bewildered expression.
“It was set up by David himself at the Topology Society. It’s for internal employees who use it without a license key, so I didn’t get the diskette.”
Silence fell in the office, and after a long silence, the major’s older sister spoke to Yunseok’s older brother.
“Yoon Seok-ah, can I go back to the US and report this to the police with the V-Stop log file here and the McLean MathTech program on my computer?”
Yoon Seok-yi hyung shook his head.
“V-Stop log files would be difficult to use as evidence. The McLean MathTech program has to look at the source code, and there is no legal way to know because the source code is only visible to the developer.”
“… .”
“Perhaps a search warrant will be required, but in my opinion it will be difficult because there is no solid evidence to warrant a search warrant. But in the United States, the judicial system is different, so why not ask your senior school?”
At Yoon-seok-hyung’s words, the major older sister shook her head and opened her mouth.
“At the end of the day, you just have a heart attack and you can’t catch it. under—-!”
Taking a long sigh, the older sister opened her eyes and said.
“David McLean, you motherfucker! Even though I have bad feelings, this is the result of my student’s hard work for two years. this motherfucker! Aaah—!”
The older sister who screamed so loudly opened her mouth.
“I don’t know if he’s a bad guy because he looks good, but this bastard was a really bad guy.”
That was then.
“But who is the bad guy?”
We were all surprised, and the major is the mother! and shouted.
The main character of the voice was Incheol.
A little while ago, the major’s older sister was screaming, and no one could hear Incheol entering the office.
“uh! In-cheol is here.”
At Yoon-seok-hyung’s words, In-cheol nodded and said hello to his brother.
“hello. president.”
In-cheol, who greeted Yoon-seok’s brother, changed his expression and opened his mouth, looking at the major’s older sister with cool eyes.
“I don’t know who you are… By any chance, didn’t I just tell my boss that I was a bad guy?”
oh… ! Incheol seemed to have misunderstood.
Before I could even step out, Yoon Seok-yi hyung held In-cheol and explained the situation, and when the explanation was over, In-cheol bowed his head and said to the major older sister.
“I’m really sorry. When I first walked in, I thought I was yelling at my boss.”
“it’s okay… yo. this.”
I told my major sister.
“Sister, this friend is Incheol. You’re my friend, so it’s okay to talk comfortably.”
So, when the brief conversation between Noona and In-cheol was over, the major older sister said to Yunseok-yi hyung.
“It’s already late, but I think we need to get rid of that malware right now. How do we get rid of it?”
“I will delete it now. Senior laptop, please give me a moment.”
“okay.”
“Five! Is your laptop really light? How much does a laptop like this cost?”
In this way, a conversation between Major’s older sister and Yunseok’s hyung began, and Incheol pressed his computer’s power button and said to me.
“You’re not leaving the office today, are you?”
I said, pointing to the major’s sister’s laptop.
“Something serious happened.”
“What’s going on?”
When my long explanation was over, Incheol said to me.
“So, if I just found out where the thesis file was sent, would that solve the problem?”
“I am only guessing that the thesis file was sent, and I am not sure what was actually sent. I don’t know anything other than that triggers are formula information.”
In response to my answer, Incheol said with the same expression.
“So, if you just find out what was sent to where, would that solve the problem?”
“It’s like that.”
Incheol said while fiddling with his chin with one hand.
“Then, it’s not like there’s no way… .”
“really?”
In-cheol nodded with an indifferent expression, and Yoon-seok said to his brother.
“Chief, didn’t you delete that malicious code?”
Yoon Seok-yi, who was operating the major’s older sister’s computer, said to In-cheol.
“yet. I was just looking through the config settings.”
“Don’t delete it. Can’t I try this once?”