Computer Virus A Virtual Program - 1170 Words

Computer Virus Definition A computer virus is a kind of program which is inserted several strings of computer codes that can destroy the function or date of computers. It can affect not only the computer which has been infected, but also a group of computers which are related to the infected one. Feature Though a computer virus is a virtual program or a section of executable code, it still seems like a biological virus, which have ability of self-propagation, mutual infection, and regeneration. Computer viruses can replicate themselves by a unique way. They can spread quickly but are often difficult to eradicate. They can attach themselves to various types of files. When files are copied or transferred from one user to another, they will†¦show more content†¦Once users update antivirus software or only the database in it, the viruses will be identified immediately. Many times, virus writers will slightly rewrite their viruses again by use of assembly instructions plus junk code or add a shell or more to easily protect their viruses escaping from detection of the antivirus software. Norton Antivirus, McAfee, PC-cillin from the United States, Kaspersky Anti-Virus from Russia, NOD32 from Slovakia, and other famous antivirus products which have a good reputation in the international community, are still limited by their abilites of detection and capabilities of shell check. The current total number of virus database are also only several hundred thousand or so, whereas there are over one hundred and thirty million new viruses discovered just last year. Self-renewal is another new feature of recent viruses. Virus can vary and be updated with help of a network. The latest version of the virus could avoid being killed and continue to run on the infected computers. The writer of Panda Virus created a virus update server which could update his virus eight times in a day, even faster than the frequency of some antivirus software updating their virus database. It would be no surprise that antivirus software cannot identify the virus. Apart from the two points above, many viruses also acquire new feature of against their enemies including antivirus software and