"Huh?" Jiangxiwen became interested when he heard this, so he hurriedly put his head over and looked at their ****. As expected, the master described in detail the invasion method a few days ago, and how to use several computers of Yujianju as broilers to send syn flood attacks to the soft server.

What is a syn attack? First of all, you need to know that syn is a handshake signal used when establishing a connection between tcp/ip.

Simply put, when a user visits a website, the computer used first sends a syn message, and the website server uses sy-ack to answer, indicating that the message has been received.

After the user's computer receives the answer, it responds with an ack message. In this way, a reliable connection can be established between the user and the website, and the data can be transmitted between the user and the website. In other words, to visit the website, it is like going to a friend's house and knocking on the door first (syn request). When the friend hears it inside, it will not open the door immediately, but ask who you are looking for (synack response), and then you will say who I am and who I am looking for (ack message response). At this time, the friend opens the door and you will go in.

Visiting the website is such a process. The difference is that the data signals are used in this process between machines. Under normal circumstances, after the website server tries to respond with sy, before the client gives back to the ack confirmation, the server will send sy to the client again within a certain period of time. When the number of retransmissions reaches the upper limit, the system will delete the access request. This intermediate process is called a semi-connection request

The syn attack takes advantage of the vulnerability of accessing the last link of the website and constantly sends a large number of semi-connection requests, which has consumed server resources and eventually leads to server blockage.

In layman's terms, after knocking on the door, the person in the room asked you who you were, but did not answer. Continue knocking on the door, run away after knocking, and then come back a while and continue knocking on the door. After knocking, run away until the door in the room was so annoyed that normal people would not have the energy to open the door.

Of course, if this example is not necessarily appropriate, when the homeowner finds someone tricks him, he can call the police. This is similar to when he finds that the server is attacked, he can use antivirus software immediately or ask experts to help clear the attack.

Syn attack is just one of the dos attacks. Dos attack means denial of service attack in Chinese, which means that the attacked website is paralyzed and denies customer access. There are many attack methods.

Qi Huanchang had heard Jiangxiwen say this concept a long time ago, and he could also attack his opponent's servers in this way, but he still didn't understand it. He asked: "Xiwen, what you taught me before was to use our machine to infect the opponent's servers through viruses, but it was the first time I heard that I was waiting for this person who claimed to be a master to give a lecture."

"Didn't you laugh at me just now? You think these two guys are really stupid. They are still bragging when they are being monitored." Jiangxi Wen said with a smile.

"Of course. I looked at the bees inside outside the honeypot. I was like God, which was very interesting. But this big bee knows a little more, and I also need to learn the skills of bees." Qi Huanchang said haha.

Jiangxi Wen patted Qi Huanchang on the shoulder and said, "In fact, this trick is nothing, it is called ddos ​​attack. The dos behind is still a denial of service attack, and the one in front is the distribution, which means distribution in Chinese. Simply put, dos attacks are one-to-one attacks, whether it is the traditional syn flood, or the pin of death, etc., and distributed is a many-to-one attack. This was used by hackers abroad last year. Generally, the target server has very good performance. One machine attack is not enough to drag the opponent's resources to death, so multiple machines are used to launch attacks at the same time, even if the performance is strong, it will be over.

In the future, computers will become more and more advanced. One-to-one attacks will gradually withdraw, and most attacks will rely on ddos. However, this method is rare now.

The software server only provides website services. If he wants to destroy it, he doesn't need to use ddos ​​to attack. This guy did this, obviously trying to trouble us, provoke us, control all our computers, and attack together. In order to prevent attacks, we use different external network IPs. He can control all our computers at the same time, which is enough to show his strength."

"No matter how powerful you have, you are still sucked in by your BT honeypot." Qi Huanchang looked excited. After he understood the DDOS attack, he no longer wanted to listen to the master pulling it off. He hurriedly asked: "When will you track their computers?"

"It has been tracked..." Jiangxi Wen smiled, "I have set up an automatic tracking system in my honeypot. The IP address of this master and this apprentice have been recorded, but I have not set up how to act after tracking."

"What?" Qi Huanchang had to look at Jiangxiwen with wide eyes again, "How did I track it, why didn't I find it?"

"D disk, hidden text files are generated under the movie folder. After any intruder is tracked, a single text file will be automatically generated. Now two people are invading, there should be two text documents, of course it is not a simple win5 hidden method..."

"Oh, I know, it's the code you taught me to hide before..." Qi Huanchang immediately intercepted and raised his hand to open the D disk, but soon he retracted his hand. At this time, there were two hackers in the machine, and any of his operations might make the other party notice.

"It's okay, these two guys are having fun, they won't find out."

Since Jiangxi Wendu said this, Qi Huanchang took a bold move and opened the D disk and found one of the hidden files. There were four springboards in total. In this era, hackers who could use four springboards as invasion paths were already considered an intermediate or above expert. Jiangxi Wen smiled slightly and said, "Enter his machine and see what some of them."

While Jiangxi Wen was speaking, Qi Huanchang couldn't wait to follow the automatic tracking path to find this person's machine, and circled four springboards in total. In this era, those who could have such invasion methods were at least intermediate or above.

The machine was found, but Qi Huanchang tried for a long time and couldn't get in. Jiangxi Wen looked at Qi Huanchang's operation without saying a word. Just when Qi Huanchang was helpless, Jiangxi Wen said: "There is a backdoor on his audio and video decoding software, and the code is..., go and check it out."

"Oh Qi Huanchang heard this and suddenly realized. Ten minutes later, he cracked the back door, entered the machine, and checked the system username. Sure enough, this person is the master who is bragging about in the honeypot now.

Qi Huanchang quietly walked around the master's computer. Some hacker attack tools and ordinary virus codes he wrote were not found, and there was no other clues that this person had a grudge against Yu Jianju or Jiangxi Wen, and there was no evidence that this heat had something to do with Jiang Qi, who was a pseudonym Qiu Zong.

"bt, I can't find anything!" Qi Huanchang was a little disappointed.

"If we find it out, we can all sue him. Judging from this person's invasion method, his personality must be very delicate. It is impossible to leave the evidence on the computer. Even if there is, it cannot be used as evidence." Jiangxi Wen said seriously.

Qi Huanchang quit helplessly and saw that the master was about to show how to use this invaded Yujianju server to attack Qingruan's website again.

The apprentice was also waiting with relish. Unfortunately, Jiangxi Wen had already put a lot of restrictions when designing this honeypot system. The other party could not use this machine to attack others. Otherwise, even the honeypot would cause unnecessary trouble to Yu Jianju. Who can prove that you designed the honeypot to catch the hacker?

The master kept using various methods, but he still couldn't succeed. Qi Huanchang was already out of breath and said, "This idiot, I want to show off. I'm embarrassed now."

However, the master was the master after all, so he quickly calmed down. He was embarrassed to look for the reason in front of his apprentice. He took out the account and password of the broiler he had controlled before and shared it with the apprentice. As expected, he received the praise and respect from his apprentice.

"There is another text that has not been opened, let's take a look." Jiangxi Wen always felt something was wrong. The backdoor used to hack the master's network just now seemed to be artificial. The master had patched all the vulnerabilities that other small software could generate, but it seemed that it was inappropriate. However, the system did not have any honeypot characteristics. It was obvious that the master's machine had become a broiler for a master hacker, and he himself had never known it.

However, the hacker did not establish an account in the master's machine, which shows that he was very cautious. While thinking, Qi Huanchang had already opened another note document recording the apprentice's machine. When the two saw it, they looked at each other.
Chapter completed!