1、广西工学院 鹿山学院 - 1 - 广西工学院鹿山学院 外文翻译 题 目： 计算机病毒 系 别： 计算机工程系 专业班级： 计软 082 班 姓 名： 周政 学 号： 20081424 指导教师： 崔亚楠 职 称： 二 一二 年 四 月 十一 日 广西工学院 鹿山学院 - 2 - Computer Virus Computer viruses are a destructive program that can replicate itself and proliferation through the network, transmission. Virus code is very smal
2、l, usually attached to other documents or procedures at the end, so they can easily hide in the system. Ability to self-replicating virus on the network so that it can spread infection to other documents and procedures, once the virus spread to the network very difficult to track down. In 1987, comp
3、uter viruses spread in the United States, and the first computer virus small ball at the end of the year spread to our country. Since then, has found a virus imported and domestic. So far, computer viruses has risen to more than 20,000 kinds； which can attack more than 90% of micro-computer. 1. The
4、characteristics of computer viruses (1) the basic characteristics of (a) infection: a computer virus as a program that can replicate itself to other normal procedures or systems of certain components, such as the disk part of the guide. This is the basic characteristic of the virus program. With the
5、 increasingly extensive network development, computer viruses can be widely disseminated through the network in a short time. (b) latent: hidden in the infected system the virus does not immediately attack； the contrary, in its pre-attack, the need for a certain period of time or have certain condit
6、ions. Within the incubation period, it does not show any disruption of operations, making it difficult to find the virus and the virus can continue to spread. Once a virus outbreak, it can cause serious damage. (c) can be triggered: Once certain conditions, the virus began to attack. This feature ca
7、n be triggered is called. Take advantage of this characteristic, we can control its transmission range and frequency of attacks. Conditions may trigger the virus is the default date, time, file type or frequency of the computer to start. (d) damage: the damage caused by computer viruses are a wide r
8、ange of - it not only undermines the computer system, delete files, change data, but also occupied system resources, such as disruption of the machine running. Its destruction of the designers attempt to show. (2) general characteristics (a) Express Impact: In 1984, Dr. Fred Kordon allowed to use th
9、e UNIX operating system XAX11 / 750 computer for virus experiments. In a number of experiments, computer paralyze the average time is 30 minutes, the shortest period of time for 5 minutes. Typically, if the infected computer associated with the Internet, then the virus can be transmitted in a matter
10、 of hours thousands of computers. (b) it is difficult to eliminate: On the one hand, day after day a new virus or its variants； the other hand, some virus may be eliminated in the resurgence of, for example, re-use when an infected floppy disk. (c) vector characteristics: the spread of the virus can
11、 be used as the normal vector information, thus avoiding the system we set up protective measures. In the normal operating system user, the virus stealthily control system. Users may also consider him the system is running normal. (d) it is difficult to detect: the virus through a variety of ways be
12、yond our control infection, in addition, with the illegal copying and the popularity of pirated software, virus detection more difficult. (e) to deceive the characteristics of: viruses often hide themselves to avoid being detected. 2. The structure of computer viruses 广西工学院 鹿山学院 - 3 - Computer virus
13、es usually five components - infection Fu, transmission modules, damage module, trigger module and main control module. (1) infection at Infection Fu, also known as virus signatures, a number of figures or characters from the ASCII coding constitute. When the normal procedure of transmission of the
14、virus when it left in the program as a virus infection at the signature. Virus infection in a program intended to, it first checks whether there is any infection site； If so, the procedure has been infected, the virus will not spread it further, and if not, on the transmission of it. The majority fo
15、llow this one-time transmission of the virus. If the virus does not check the site of infection, it may happen repeatedly transmitted, the length of the program would continue to increase, this situation is rare. (2) transmission module This is the transmission module boarding procedures. It complet
16、ed three tasks: search executable file or document coverage, to check whether the document has infected Fu, transmitted it - if not found to be infected with FU, on the person boarding procedures Writing virus code. (3) damage module It is responsible for the designers of the destruction in accordan
17、ce with the virus code in an attempt to undermine the implementation of mission, including delete files, delete data, formatted floppy disk and hard disk, reducing the efficiency and reduce the use of computer space. (4) trigger module Its mission is to check whether the trigger conditions (for exam
18、ple, the date, time, resources, and transmission time, interrupt call, start number, etc.). If the conditions are ripe, it return true value, and damage mediator module damage, otherwise it return false value. (5) the main control module Its control of the four modules. In addition, it has procedure
19、s to ensure that the infected can continue to work correctly, the accident would not crash happened. 3. Computer Virus Classification (1) by the parasitic Category By parasitic, computer viruses can be divided into lead-virus, file virus and mixed virus. * Boot virus: parasites in the disk guide mea
20、ns those parts of a computer virus. It is a common virus, the use of computer systems do not usually check the guide part of the content is correct weaknesses, and retained in memory and monitor system operation, one has the opportunity to infection and destruction. According to the location of para
21、sites in the disk, it can further be divided into the Master Boot Record boot record viruses and paragraph virus. The former master boot hard drive transmission parts, such as marijuana virus, 2708 virus, porch virus； Record paragraph of transmission of the virus commonly used hard drive Record para
22、graphs, such as small ball virus, Girl virus. (2) by the consequences of classification From the consequences of watch, computer viruses can be divided into benign viruses and vicious virus. Benign virus would destroy data or programs, but it will not make computer systems paralyzed. Initiator of th
23、e virus are most mischievous hackers - they created the virus is not in order to undermine the system, but in order to show off their technical capacity； Some hackers use these viruses to disseminate their political thought and ideas, such as small ball virus and Ambulance car virus. Vicious virus would destroy data and systems, resulting in paralysis of the entire computer, such as
