Riding the wind of rebirth

After hanging up the phone, Zhou Zhi began to think about it.

"Elbow! How is it?" Lao Chi Ri brought Li Lu and the others back. Liang Guangping and Liu Hongtao were supposed to go back to the base, but because they were worried about Zhou Zhi, they followed them. Liang Guangping asked as soon as he stepped into the door.

"It's no big deal." Zhou Zhi said with a slight sigh of relief. Although the matter was very serious, after some analysis, Zhou Zhi found that Black Cat did not spy on the group's secrets. Although he found a user with extremely high permissions to lurk into the group's intranet, he did not make any big moves.

This approach is more like that of a person who is interested in information technology verifying his own ideas and creativity.

"If there's anything, you must tell me." Li Lu's eyes were filled with the rage of gossip: "Don't hide it from us."

"We found that the system was hacked by a hacker. Fortunately, the hacker spared us from causing any serious damage." Zhou Zhi said casually, "But he also revealed his true colors. We are closely monitoring him."

Li Lu, Liang Guangping and Liu Hongtao exchanged glances. All three of them saw shock in each other's eyes. Grandpa Chi Ri's divination was quite effective! The first half of the divination was already accurate!

"How did this hacker get in? Isn't your school's system built by the Clover Group? They make operating systems, anti-virus software, and firewalls. How could they be hacked?"

"This is a loophole left over from the UNIX era. The computing power of previous chips was not enough, so this idea could not be realized, so people did not think it was a bug." Zhou Zhi roughly explained the problem to the two of them: "As computer computing power increased, this bug was exploited."

The no-op sled needs to be set up to fill a long string of no-op instructions to occupy storage space, and then use a counter to find the return address field stored in this space one by one, and finally fill in the malicious code to turn it into output information to attack the system. This method would be discovered by the system as soon as it was run in systems with extremely tight resources in the past, and it might even crash directly, so it was indeed just an idea before.

Thinking of this, Zhou Zhi suddenly had an idea and rushed to the computer and sat down. Just as he was about to log in, he stood up again: "Brother Tao, log in to the Clover Forum with your user name. Remember to use the IP hidden mode."

Liu Hongtao stepped forward and operated it skillfully, logging in successfully in a few seconds: "Here, what do you want to use it for?"

Zhou Zhi sat down again. "The hacker successfully hacked into the system by using stack overflow and no-op sled. I'll check the relevant papers on these two intrusion methods in the school."

"Then why use my user?" Nowadays, the networks of major campuses can access each other, and some academic resources have also been partially shared. This is actually an interoperability project jointly launched by Clover Group, Shu University and several foreign universities. After the initial success, other universities in the campus network joined in like fish smelling fishy smell, and together they established an academic website that integrates functions such as information query and paper retrieval - Yizhi.net.

The "Academic" tab in the search engine of the JAVA version of Clover Browser is actually supported by Yizhi.com.

Zhou Zhi was afraid of using his own user to search for papers on the two technologies, and was even afraid that using a user in Liangshan Prefecture would arouse Black Cat's vigilance, so he changed the user and hid the IP location.

Liu Hongtao is a long-time visitor to the information technology sector, so the remaining information should not arouse any suspicion.

Switching from Clover Browser to Yizhi.com, Zhou Zhi quickly retrieved several papers related to stack overflow and no-op sled.

There are many articles about stack overflow vulnerabilities, because this overflow vulnerability was discovered as early as the DOS era, and was used as a means of attack on a large scale in the Windows era, so its principle is widely known. However, there is only one paper about the no-op sled, and it is relatively short and does not introduce too many technical details. It mainly describes the possibility of such operation from the perspective of mathematical logic and microcontroller principles.

When Zhou Zhi saw the author of the article, he was completely stunned. This person was so familiar to him that he could not be more familiar with him. He was even his immediate superior in all Shu University's computer cooperation projects, the director of Shu University's Computer Department, Mai Mingdong.

This is a bit nonsensical. Mai Mingdong was just named an academician last year for several outstanding information technology achievements of Shu University and enjoys the expert allowance of the State Council. To say that this old man would want to use such a novel method as an air-operated sled to play such a joke on the younger generations of the Clover Group, then the sun is rising from the west.

However, there is only one article about the empty operation sled in the entire Yizhi.com. Even Zhou Zhi suspected that the author of the paper might come up with some other name. He only conducted a fuzzy search based on the word "empty operation" and found the culprit with the word "sled". There was only this one article, and the author was an old acquaintance.

Still holding the idea of ​​giving it a try, Zhou Zhi picked up the mobile phone beside him and called Mai Mingdong.

"Elbow! When will you return to Shudu?!" The call was just connected and Mai Mingdong asked him the first question.
"Why should I go back to Shudu?" Zhou Zhi was stunned.

"I'm almost too busy now! Can you count how many scientific research projects our school is currently undertaking? Just count the ones related to you, how many are there?!"

"Aren't those projects being followed up? The progress is in line with expectations. Is there a problem with the system?"

"Well, that's not the case, but I still hope you can return to the Eighth System to take charge..."

"No, no, no, I'm from the first department, the Chinese department." Zhou Zhi said firmly, and even made a swearing gesture that Mai Mingdong couldn't see at all: "I'm already involved in too many scientific research tasks for the eighth department..."

"Bullshit! The Clover Group isn't yours?!"

"Haha, Mr. Mai, you still know that I have such a mess?" Zhou Zhi quickly said, "If it delays my graduate school graduation, then I really dare not go back."

"You bastard!" Mai Mingdong roughly knew the burden that Mr. Gu had given Zhou Zhi. The Middle Chinese sound simulation project was a major project that combined humanities and social sciences with information technology. Director Song had already agreed to include it in the national key projects after the preliminary work was completed. Now this kid was hiding in Liangshan Prefecture under the pretext of "seclusion and research". Mai Mingdong was busy with all kinds of things and really couldn't run to Lianhe Township to catch him.

I could only curse angrily, and then suddenly asked: "Then why did you call me?"

"It's like this." Zhou Zhi said quickly, "I saw an article on Yizhi.com about the 'no-op sled' attack on the system stack overflow vulnerability. It was signed by you. I have some questions I want to ask you."

"What do you mean by empty-handed sledding? I don't know? Are you sure I wrote the article?"

"Huh?!" (End of Chapter)