Antivirus is a term given to protection software specially designed to protect computers against all kinds of harmful computer viruses. It also provides protection against malware includes viruses, keyloggers, the hijackers and the Trojan horse.
A computer virus is a small software or code that replicates itself and spreads from one computer to another. An entry of this code in any computer significantly interferes with the operation and function of the computer. These codes are usually attached to programs such as excel, word, outlook, PowerPoint, and word perfect. When these programs are run the virus attached to is triggered to run on causing a wide range of problems, including corruption of files, deleting data and email spam.
Viruses are normally distributed through the networks of email, download or shared disk. If any infected file is attached to any of these sources specified computer system is designed to infect open infected files. Some common symptoms indicating the viral infection are slow operation, restart, irregular operation of applications, unusual error message printing problem, often hanging, distorted menus and dialog boxes, and double extension on any attachment.
Computer viruses are widespread in the world today. a new virus is introduced every day and therefore the system must be updated at regular intervals to ensure that the system is free from virus infection. There are primarily two approaches to identify and destroy all the files of the system.
The first is the approach of virus dictionary that includes all the basic information on viruses, threats, their behaviour and their causes. When a new virus is introduced data are fed in the dictionary by downloading of updates. This information is still used by various anti software virus to identify and destroy attachments and threatening and suspicious files. Although it is a very effective program, but sometimes it fails to work effectively. This is because it can catch only these viruses whose information is fed in the dictionary. Any suspicious movement is not considered by this approach, and therefore an alternative approach is given more preference.
The second is the suspicious behaviour approach that monitors the characteristics and behavior of all programs running on the computer. Any type of suspicious movement is detected by this approach that infection by the virus and a warning message is then send to the user in order to ensure an appropriate action in the right time. This approach is relatively more effective than the approach of the dictionary as it is not dependent on any dictionary or stored information.
Approach of behavior sometimes even suspect may give a false alarm, but the user must be paid to the technology. A good knowledge and understanding of computers and all kinds of threats affecting the system is more important to ensure a high level protection against viruses and other threats.
For more information, see Anti Virus software.