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Chapter 326 Abnormal Connection

In the face of Wu Dong's question, Lin Hong intended to popularize these basic knowledge for them, so he gave a detailed explanation. Pen "Fun" Pavilion www.biquge.info (""")

Proxy servers have been around for a long time, and many people may never have had the opportunity to touch this thing.

Many non-technical people can't even understand why this service exists.

To put it simply, it's like a passage that helps you get things done, but since you need to pass through it, it will also leave traces in the passage.

Using proxy server intrusion, sometimes there may be only one springboard, but it is precisely because of the existence of this springboard that the security factor can be increased several times.

If you are on the Internet, this advantage is even more obvious, because the proxy server you use may be in a corner of another country, even if the other party wants to track down, in addition to invading the server yourself, either contact the administrator to ask for records, or go directly to the computer room where the proxy server is located, log in to his server for query.

It may seem like a very simple step, but it is very difficult to do.

And if the intruder's technology is a little higher, and the proxy server is set up by the intruder himself, rather than directly using someone else's service, then it will be many times more difficult to trace.

After all, the way to set up such a proxy service is very simple, and if the other party also cleans up the records in the server regularly in a timely manner, then a relatively large amount of concealment can be achieved on the books. Unless you are a master, you can only "look at the ocean and sigh".

Lin Hong finally said: "At present, one of the most popular proxy server software on the Internet is BitMessenger, which can basically achieve true anonymity due to the use of a unique design structure and a very strong encryption algorithm. Since it is based on a peer-to-peer protocol, it can actually be used inside a local area network, provided that there are enough nodes inside this local area network, of course. Templar"

Bit Messenger ...... The three people present listened very carefully, and when they heard Lin Hong introduce this software so solemnly, they all stayed in their hearts and decided to go back and study it carefully.

"In order to achieve a safer disguise, I need to set up a proxy server on another machine first, and not let this proxy server save access records, and the way to achieve this is very simple, that is, the records are generated, and they are deleted immediately......"

Lin Hong said, and began to officially start the invasion.

"I wrote a small tool before, this tool has two main functions, one is to scan the computers active on the network on the specified IP segment, to see which computers are online; Another feature is to scan a specific computer to see which ports or services it has opened. ”

In the past, in order to find the active hosts on the network, hackers had to manually write specific commands to operate, and if they found the target hosts, they had to slowly analyze which ports the other party had opened, basically testing them one by one.

Obviously, this manual method is not only cumbersome but also relatively inefficient.

Later, some people began to write all kinds of automation tools, and all operations were handled automatically, as long as the operator entered specific parameters. Even in the graphical interface, the operator can perform these actions immediately with just a few clicks of the mouse.

The tool written by Lin Hong is from the command line and must be used with various parameters.

Lin Hong first used the network command to check his IP, then tracked the packet sending path to understand the situation of the gateway, and then entered an IP segment address under his tool. After entering, the command interface starts to swipe upwards with the scanned information.

The information was all in English, and it was a variety of fixed professional terms and abbreviations, and Wu Da and the three of them stood behind them and watched, only feeling dazzled and completely unable to understand what it meant.

However, this kind of scene where the characters keep swiping upwards is very much in line with the plot of their imagination of hackers invading the computer, and they wish they were the ones who operated the computer. Although they can't understand the above content, one thing is certain, that is, the boss of their dormitory is very good at computer technology. Templar

Since they would choose a computer major, they were naturally very interested in computers, so at this time, they all admired Lin Hong so much, and they thought in their hearts that they must let him give him guidance in the future.

The scan soon stopped, and Lin Hong opened a file, which was the result of the scan, which contained the host currently active online, as well as a general situation of the host, such as IP address, operating system, open port, etc.

Some of these hosts are other people's personal computers, and some servers set up by the school, considering the stability problem, Lin Hong chose the server.

Most of the systems installed on the server are window or unix, both of which Lin Hong knows about some vulnerabilities, but he uses some vulnerabilities that have been commonly exposed. Of course, these vulnerabilities are only circulated in some internal hacker forums abroad, and ordinary people basically can't see them.

Lin Hongjian pointed like flying, while invading, he explained in detail to a few people in the dormitory what techniques he used, and the whole process was like a textbook. He knew everything about it, as if he had invaded it countless times before.

The other three people in the 604 dormitory listened fascinated, none of them were dull-minded people, and under Lin Hong's deliberate actions, although they didn't understand everything, they had already understood the basic processes and principles. Although the amount of information Lin Hong said was very large, this kind of on-site demonstration teaching gave them a very deep impression and had a great impact on them in the future.

Lin Hong manually set up three proxy servers by himself, and then used this as a springboard to start blatantly looking for the database server in the Academic Affairs Office.

The method he used was to find the software that Wu Da said.

"The next work is a bit boring, because I don't know the IP address of the server, I can only try one by one, all kinds of methods can be used, for example, you can also directly find the counselor's computer, and then through that computer to find it, anyway, how convenient how to come. One of the vulnerabilities I'm exploiting now is basically a problem with the computer's default settings, which are not modified by the user in time, giving intruders an opportunity to ......"

Seeing Lin Hong constantly connecting to other people's computers, Wu Da and the three of them couldn't help but break into a cold sweat, especially Wu Da and Li Qi, they had used computers before, but they never knew that others could enter their computers to check things so easily.

Soon, Lin Hong found clues from a computer, he found a software, that software constantly exchanged information with another computer, intercepted a few packets and analyzed it, the information was not encrypted, but plaintext TCP/IP packets.

TCP/IP packets, Wu Da and they had never been in contact with before, and they had never imagined that their usual external data exchange was actually carried out in this way.

Seeing Lin Hong peeling out the data one by one like peeling bamboo shoots, they found that they had a lot to learn, and at the same time, they wondered how the other party learned this knowledge? Everyone is about the same age, why is there such a big gap?

Some difficult steps, Lin Hong didn't explain to them for the time being, a few steps flashed, before they could react, he had already won the access to the database server, and then carried out the operation of elevating rights, and the control was in hand.

This is a SUN workstation running UNIX and the database software is Oracle.

These things can't be explained clearly for a while, so Lin Hong will omit them, anyway, there will be opportunities in the future.

He pulled up a piece of software from his software package, which was a tool to connect to the oracle database, and after filling in the information such as the account number and password, he connected to the database.

"Okay, now that we're connected to the database server of the Academic Affairs Office, we can now query the data inside."

Because he had to take care of his roommates, Lin Hong did a bit of a hard job in this invasion process, originally according to his approach, he could quickly find the target and successfully invade, but now he has come full circle, and the methods he uses now are basically the usual methods.

Wu Da suddenly perked up when he heard this: "That girl's name is Su Mei, quickly check her information." ”

Her name is Chinese, originally Linux support for Chinese is not good, fortunately, after Lin Hong returned, he made a transformation and integrated the Chinese character system, otherwise it is really not good how to proceed.

Lin Hong entered "Su Mei" in the "name" field, and then set the query conditions, and after entering, more than a dozen records immediately appeared.

Seeing this, Li Qi was immediately surprised: "There are so many people named Su Mei in our school?" ”

"Now there are more and more people, and there are indeed a lot of names with the same two words." Wu Dong said, "The four of us in the dormitory are all two words, wait and check to see how many have the same name." ”

"Dongdong is right, wait a minute, you must check it out." Zhang Da was also very interested in his proposal.

The records shown are all the students enrolled in Mizuki University since its founding, and the oldest one is even 76 years old.

"See, it turned out to be a school of management, a sophomore this year, living in 307 ...... building 5 of the girls' dormitory" Zhang Da's eyes were still sharp, and he quickly filtered other useless information and found what he really wanted to find.

He hurriedly found a pen and paper and recorded this information.

Richie: "Boss, you're amazing!" Now the information of all teachers and students in the school is in our hands! ”

"Shouldn't we do something with that information?" Zhang Da began to have some ideas.

Wu Dongdao: "What to do?" This information can't be made public, right? If it is made public, won't it tell others that we have hacked into the school's system? ”

Li Qi: "That's it, that's it, let's just see for ourselves, don't bother the boss." ”

Just as they were discussing with each other, Lin Hong focused on the computer, because he found that among the people who logged in to the database server at the moment, there was something abnormal, to be precise, the network segment to which the IP address of the connection belonged belonged to the student dormitory.

"Someone, like us, hacked into this database server."

Lin Hong's words immediately attracted the attention of the other three back to the display screen.