Antivirus is a term given to a protective software specifically designed to protect computers from all kind of viruses harmful to a computer system. It also gives protection against malicious software that includes viruses, keyloggers, hijackers, and Trojan.
A computer virus is a small software program or code that replicates itself and spreads from one computer to another. An entry of this code in any computer drastically interferes with the operation and function of the computer. Such codes are usually attached to programs like excel, word, outlook, power point, and word perfect. When these programs are run the virus attached to it is triggered to run on causing a wide range of problems including file corruption, data deletion, and email spamming.
Viruses are normally spread through networks by means of email, download, or shared disk. If any infected file is attached to any of these sources then the specified computer system is designed to infect upon opening the infected files. Some of the common signs indicating viral infection are slow operation, frequent re-starting, improper functioning of applications, problem in printing, unusual error message, frequent hanging, distorted menus and dialog boxes, and double extension on any attachment.
Computer viruses are highly prevalent in the present day world. a new virus is being introduced every day and hence the system has to be updated at regular intervals to ensure that the system is free from viral infection. There are mainly two approaches to identify and destroy all infected files from the system.
The first approach is the virus dictionary approach that beholds all the basic information of the viruses, their threats, their behavior and their causes. When a new virus is introduced the data is fed into the dictionary by downloading updates. This information is further used by various anti virus software programs to identify and destroy suspicious and threatening files and attachments. Although this is a very effective program but at times it fails to work effectively. This is because it can catch only those viruses whose information is fed into the dictionary. Any other suspicious movement is not considered by this approach and therefore another approach is given more preference.
The second approach is the suspicious behavior approach that monitors characteristics and behavior of all programs running on the computer. Any kind of suspicious movement is detected by this approach as virus infection and then a warning message is send to the user to ensure appropriate action at the right time. This approach is comparatively more effective than the dictionary approach as this is not dependent on any kind of dictionary or stored information.
At times even suspicious behavior approach can give a false warning but the user should be well versed with the technology. A good knowledge and understanding of computers and all kind of threats affecting the system is most significant to ensure high level of protection against virus and other threats.