Shulou(Shulou.com)06/02 Report--

Editor to share with you according to the spread of computer viruses can be divided into several categories, I hope you will gain something after reading this article, let's discuss it together!

According to the transmission medium of computer virus, it can be divided into stand-alone virus and network virus. Stand-alone viruses are previous DOS viruses, Windows viruses and macro viruses that can run under multiple operating systems; network viruses are computer viruses that infect executable files through the computer network.

Correlation

Computer virus (Computer Virus) is a group of computer instructions or program codes that programmers insert into computer programs that destroy computer functions or data, can affect the use of the computer, and can copy themselves.

Computer viruses are artificial, destructive, contagious and latent programs that destroy computer information or systems. It does not exist independently, but is hidden in other executable programs. After the virus in the computer, the light will affect the running speed of the machine, and if it is serious, the crash system will be destroyed; therefore, the virus will bring great losses to users. Usually, we call this destructive program a computer virus.

According to the transmission medium of computer virus, it can be divided into stand-alone virus and network virus.

Stand-alone virus

Stand-alone viruses are previous DOS viruses, Windows viruses, and macro viruses that can run under multiple operating systems.

DOS virus is a virus program written on MS-DOS and its compatible operating system, such as "Black Friday", "DIR" and so on. They run on DOS platform. Because Win3.x/Win9x still uses or contains DOS kernel, this kind of virus can still attack Windows system, attack on Windows platform, and infect files on hard disk.

Windows virus is a pure 32-bit virus program written on Win3.x/Win9x, such as the CIH virus that endangers the world on April 26th, this kind of virus runs on the Windows platform, destroys the hard disk boot area, infects system files and executable files, destroys user data, and even erases the motherboard BIOS, causing motherboard damage. As we all know, there are a staggering number of viruses on DOS and Win3.x/Win9x, while there are much fewer viruses on Windows NT.

Macro virus is a virus written by Office's unique "Macro". It specifically attacks Microsoft Office series Word and Excel files. The virus can run not only in the Windows environment, but also in Microsoft Office software on OS/2 or MAC OS, because Office software has multiple versions of For Windows, For OS/2 or For MAC OS, and the definition of "macro" is the same in all versions.

So as long as the Office document is opened on these operating systems, the macro virus begins to break out, infect other Office documents, change file properties, or even delete files, such as the July killer macro virus, which will pop up on any day in July, asking the user to choose "OK" or "cancel". If you press "cancel", a command to delete disk C will be added to autoexec.bat. When rebooting, all data on disk C will be deleted.

How to prevent stand-alone virus?

To guard against stand-alone viruses, you should first consider that each antivirus product has its limitations, so it is best to prepare several sets of antivirus software and use them to cross-kill virus, and the antivirus software should be upgraded in time; regularly check the hard disk with antivirus software, if you are using Win9x (CIH virus does not work on Windows NT and Windows 2000), be sure to check for CIH virus before the 26th of each month, or skip the system date to 26th It is best to install virus real-time monitoring software in the system (usually with antivirus software); all CDs and floppy disks ready to go on the computer must be checked for virus before they can be used; use Ghost software to back up the system partition into a file and store it on other partitions, once the system is destroyed by the virus, it can be restored in a few minutes, but the hard disk must be antivirus before backup. It is best to divide the hard disk into multiple logical disks, such as C, D, E, each disk is preferably in FAT32 format, C disk as the system disk, of course, the capacity should be larger, C disk had better be FAT32 format, the capacity should be greater than 2G

The advantage of this setting is that it helps to improve the running speed of the system. In addition, if disk C is destroyed by CIH virus, as long as it is in FAT32 format and the capacity is greater than 2G, 98% of the data on disk C can be recovered with general antivirus software. There are at least nine variants of the CIH virus, including V1.2 and V1.3 on April 26, V1.4 on the 26th of each month, and some versions on June 26.

Network virus

Network virus: a computer virus that infects executable files through a computer network.

In a broad sense, a virus that can spread through the network and destroy some network components (servers, clients, switching and routing devices) is a network virus. In a narrow sense, the virus limited to the scope of the network is the network virus, that is, the network virus should make full use of the network protocol and network architecture as its transmission way or mechanism, and the destruction of the network virus should also be aimed at the network.

Characteristics

(1) the rate of infection is very fast.

Under the condition of stand-alone operation, the virus will only be infected from one computer to another through the floppy disk, and the virus can spread rapidly through the network communication platform in the whole network system. Combined with the relevant test results, under the normal operation of the PC network, if a workstation has a virus, it will infect hundreds of computer devices in a short period of more than ten minutes.

(2) the diffusion area is very wide.

In the network environment, the virus spreads quickly and widely, and it can infect all computers in the local area network in a very short time, and it can also spread the virus thousands of miles away through remote workstations in a short time.

(3) Diversified forms of communication

For computer network systems, the virus is mainly spread through the basic way of "workstation-server workstation". However, the forms of virus transmission are diversified.

(4) it cannot be completely cleared.

If the virus exists on a single machine, the virus can be completely eliminated by deleting files carrying the virus or low-level formatted hard disk. If a workstation cannot be thoroughly disinfected in the whole network environment, it will infect the devices in the entire network system. It is also possible that a workstation is immediately infected by another workstation carrying the virus as soon as it is cleared. In view of this kind of problem, only to carry out the corresponding virus killing and removal of the workstation, it is impossible to completely solve and eliminate the harm caused by the virus to the whole network system.

Prevention and control principles and strategies

(1) strengthen the security awareness of network users.

Network virus will exist in documents, computer users need to strengthen their own security awareness, not randomly click and download unfamiliar documents, so that the probability of computer infection with network virus is reduced. In addition, when browsing the web, it is not easy to click on unfamiliar web pages, mainly because there may be malicious program code in the web pages and pop-up windows. Therefore, web page virus is a widely spread and destructive network virus program. Computer users need to strengthen their own network security and virus prevention awareness, strictly regulate their own network behavior, refuse to visit illegal websites, and avoid losses. it also prevents the computer from being attacked by the network virus.

(2) update the computer system in time.

The computer will regularly detect its own shortcomings and vulnerabilities, and release system patches. Computer network users need to download these patches in time and install them to prevent network viruses from invading the computer through system vulnerabilities, thus causing inestimable losses. Computer users need to update and upgrade the system in time to maintain the security of the computer, in addition, close the unused computer ports, and upgrade the antivirus software installed in the system in time, and use these antivirus software to effectively monitor the network virus, so as to prevent the virus effectively.

(3) install firewall scientifically.

Installing a firewall at the interface location of the internal and external network of the computer network is also an important measure to maintain computer security. The firewall can effectively isolate the internal network from the external network and effectively improve the security of the computer network. If the network virus program wants to attack the computer, the virus can only avoid and destroy the firewall first, so as to prevent computer users from being attacked. The opening level of the firewall is different, and computer users need to choose the corresponding level on their own.

(4) install antivirus software effectively

At present, antivirus software is a common method to detect and kill network viruses, but many users can not correctly understand the role of antivirus software at the beginning. With the continuous emergence of computer network viruses, people begin to realize the importance of antivirus software. And the improvement and ability of antivirus software itself also make people better accept antivirus software. The current antivirus software can monitor the computer around the clock and monitor the network virus in real time. And the timely update of antivirus software and virus database can effectively detect and kill new network viruses, and its adaptability is relatively strong. Long-term use of antivirus software can be found that antivirus software can well check and kill network viruses. At the same time, the antivirus software will not occupy too much resources of the system, and sometimes the computer runs slowly because the antivirus software is filtering network viruses. In addition, the use of antivirus software is also more convenient, even if the computer is poisoned, it can save itself in a short time.

(5) make a good backup of data files

If the network virus invades into the computer, it will cause the computer system to be paralyzed, so computer users need to back up the important data and files in the computer in their daily use. through this method to reduce the losses caused by network viruses to computer users.

After reading this article, I believe you have a certain understanding of "classification can be divided into several categories according to the transmission media of computer viruses". If you want to know more related knowledge, welcome to follow the industry information channel, thank you for your reading!

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