In the computer virus first appeared, people 's lack of awareness of computer viruses , awareness is not strong , not enough deep understanding his role , he had a lot of communication, running amok . Almost every networked computer networking or do not have , without exception, suffered the invasion of viruses , but also to our work and learning has brought great prejudice . With the computer in all areas of social life, the extensive use of computer virus attacks and prevention technology is constantly expanding upgraded. According to reports , the world suffer from computer virus infections and attacks of hundreds of millions of events , which seriously interferes with the normal lives of the people , to the development of computer networks has also brought negative impact. However , a computer virus technology has applications in the military side, the Gulf War , the Kosovo War, the two sides have the use of computer viruses to attack the enemy in order to destroy the other's weapon control systems and computer networks throughout the military , the virus application as an application of high-tech weapons to achieve a certain goal . Finally, with the growing popularity of computer networks , prevent computer viruses will be more highly valued by all the world .
在計算機病毒剛顯露出來時，許多人對計算機病毒的意識不夠，防備認識不強，還沒趕得及深刻意識他的效用，他就已經數量多廣泛散布，不顧一切行動蠻橫。幾乎每一臺聯網還是沒聯網的計算機都無一律外的遭遭受病毒的侵入國，也給我們的辦公和學習帶來了莫大的有害于。

    First, the origin of the virus

    1949 by von ? Neumann presents a prototype of a concept of the virus , a possibility , but did not arouse the slightest attention. After a lapse of 10 years , Bell Laboratories in the United States , these essentials are applied to something called the " core war" power game. This game was created by three young engineers at Bell Labs invented . The idea of ??the game just to write about the role of the virus , the main idea is: each party to write a program on one computer to inject the two programs fight each other on the telephone system , and sometimes they would lay down some of the barriers to stop to repair instruction is modified , when it was trapped , it copied once, so that you can escape from danger because they are present in the core of the computer's memory , hence the name " core War ." During that time , computers are relatively independent , not networked , so there is no how spread , spread only in a small area . By the end of 1988 , only in the country's national statistics department discovered the little ball viruses. In the following years, the development of the virus is getting faster and faster .
1949年，由馮?諾伊曼提出了一種對病毒最新大概的形狀的一個概念，一種有可能性，不過沒引動許多人的一丁點兒關心注視。時隔10年，在美國的貝爾實驗室中，這些個要點被應用于一種叫做“磁芯大戰”的電游戲中。這個游戲是由貝爾實驗室的三個年青工程師創造出來的。

    Second, the type and characteristics of computer virus

    A computer virus is by copying itself to infect other programs or program instruction code . When the infected file is run , the virus also will run and copy itself to infect other programs . However, the benign virus is not malicious code attacks sex , only occupies system resources, let the system run slower. But for most it is a vicious virus carrying malicious code attacks of poison , once excited , can infect and destroy . Since the 1980s, the first one written by the Morris "worm " virus program inception, the world has emerged a variety of different types of viruses . There are the following main viruses: "Beautiful Killer " (Melissa) virus , " Papa " (Papa) virus , "mad cow " (Mad Cow) virus and the " Papa B" virus , "Happy 1999" macro virus , " Xiu Xiu " (Ping) bombardment viruses, Blaster virus , panda virus , Trojan horse virus.

    Summarize , computer viruses have the following characteristics: First, subtle and strong . Unaware of the virus can infect a computer without the case to be noticed , until the discovery , it has caused serious consequences. The second is the ability to propagate . When the computer is infected , you can quickly " disease ." Three are transmitted through broad. Available through mobile devices, wired and wireless networks, hardware and other multi- channel automatic intrusion computer and keep infection. Four is a long incubation period . Long-term latent virus in the computer system can not attack, etc. to achieve excitation conditions, on the attack damage the system. Five is the damage is great . Once the computer virus attack , ranging from disrupting system operation , heavy damage to disk data , delete files, and even lead to paralysis of the entire computer system .

    Third, the use of computer viruses to analyze technical analysis

    Computer software have been designed primarily to pursue the goal of improving information processing capabilities and lower production costs , but often overlooked security issues. This gives computer viruses for the development of a vast space, and the various components of a computer system , interface, conversion between the layers , there are many loopholes . What hardware design coupled with the lack of overall security reasons , it is impossible to achieve 100% safe , the software also more likely to present risks. The vulnerability of computer systems for the generation and dissemination of computer viruses provides an opportunity ; Global World Wide Web so that the " network globalization" , the more computer viruses created to implement destructible environments ; With the development of electronic technology maturing, new computer application technology studied under field are increasingly being used as computer viruses provides a platform to achieve destruction . Foreign experts believe that computer standardization , the standard message format , distributed digital processing , reprogrammable embedded computers, network communications, software standardization, standard data link , etc. can make a computer virus invasion possible.

    Computer virus core technology is the solution to virus invasion . Its goal is to attack a variety of computer systems , as well as host to a variety of sensors , bridges , etc., to make their computers by tricking at the crucial moment , which led to crashes, can not play a role. From a technical point of view, viruses are the following :
1 using radio mode .

The virus is mainly transmitted to each other via radio electronic systems . This approach is the best way to inject a computer virus , people are not easily noticed , but it is also the most difficult technical way . Approach generally adopted are: ① directly through to the other side of the radio receiver electronic system or electronic device to transmit the virus code , so that the receiver processing to the host of the virus , in order to achieve the purpose of destruction . ② posing as legitimate wireless transmission of data. Using standard protocols and formats of radio emission pattern , so that the same can be like legitimate signal into the receiver , to destroy . ③ looking at each other in all aspects of information systems most likely places for viruses invade the injection .
    (2) a " cure " approach. Ie, the first injection of the virus chip hardware and software, and then put them directly or indirectly to each other , so that the virus infected the other electronic systems , and thus attack the target computer. This method is very subtle, even if exposed components are thoroughly detected , nor that it is not able to explain some other special features. It is because there are still too many computer components country or from foreign imports , so will be very susceptible to chips viruses.

    3 using backdoor attacks. Backdoor , is a computer security system a small hole that allows users to bypass normal security measures into the system. Such as early windows 98 system .

    4 using the data control chain invasively . Through remote modification technique , changing the normal data path control chain .
Of course, there are some other injection method , there is not much to explain .

    Third, the computer virus prevention methods can be used from the management and technical prevention

    1 preventive management .
    ( 1 ) do not use the software of unknown origin , especially pirated software. Room should be prohibited without the detection of moving disk into the computer , is strictly prohibited on the machine to play games. Because the game 's runtime environment more likely to spread the virus .

    ( 2 ) of the unit using a computer should be strict permissions.

    ( 3 ) for all of the system disk and removable disk write protected against disk files are infected.

    ( 4 ) the system critical files to be backed up , especially the data to be backed up regularly.

    ( 5 ) on the network to limit the exchange of executable code , build good good password , set reasonable read and write permissions .

    These are suitable for small local units , the computer's development has already technically and applications become a social problem in the end, or the need for countries to develop laws and regulations apply.

    (2) The prevention techniques and methods
    ( 1 ) With memory resident anti-virus program
    At system startup disk AUTOEXE.BAT file to add a virus detection program that will constantly monitored viral invasion , and the disk to be checked. Since this method takes up memory space, but also easily lead to conflicts with other programs , some viruses escape the antivirus program's functionality , so can not use it as the main weapon against the virus .

    ( 2 ) detection of the file before running
    This method is mainly used antivirus software to check the anti-virus software can not so clear all viruses, so we should pay attention to prevention .

    ( 3 ) change the properties of the document
    Read the document can not be modified , some viruses can only remove read-only flag can not be changed attributes. This method is an easy way to prevent the virus . But it is only for general purpose file virus .

    ( 4 ) changing the file extension
    Because the computer is infected file must be used to understand the properties of each of the different files must use a different mode of transmission , the executable file extension changes, most virus will lose its effectiveness .

    IV Conclusion

    Although various types of viruses , antivirus software is also more advanced . However, virus updates , and updating speed is very fast, we do not take it lightly. To establish a good safety awareness to the computer virus protection and achieve as much as possible to avoid losses.