Last updated 2 months 1 week ago by isp-admin




A list of antivirus software can be found here.

Definition of Virus

The development of computer technology has not only brought efficiency and reliability for human beings, but has also brought security problems. The era of harmful computer software began after the theory of self-replicating programs was proposed by a Hungarian scientist named John Von Neumann (1903-1957). Harmful computer software is often known as viruses, however, there are several varieties, viz:

worms, trojan horses, spyware, and rootkits.

According to the Compact Oxford English Dictionary of Current English a virus is “a piece of code surreptitiously introduced into a system in order to corrupt it or destroy data”. A virus is just one type of malicious software known as malware.

Virus Pioneers

The first computer virus to infect “small computers” was invented by Richard Skrenta, a high school student from Pennsylvania, during the winter of 1982. However, the first virus to infect personal computers was “The Brain,” created by Pakistani brothers Basit Farooq Alvi and Amjad Farooq Alvi. The first worm, an autonomous program that makes copies of itself from machine to machine across a network, was made by a young programmer, Robert T. Morris, Jr. He was later convicted and sentenced to three years probation, 400 hours of community service and fined $10,000.

Birth of Antivirus

The emergence of viruses and other malware raised a need for computer security. Computer programmers started to develop anti-virus software as a solution. "The Reeper," an antivirus program designed to fight "The Creeper" virus on the Tenex operating system, was the first known antivirus program. However, the antivirus program that revolutionized the global market of computer protection software was Norton Antivirus released in 1990.

These days there are many antivirus software available on the market. Some of them are

  • Norton Internet Security 2009
  • Avira AntiVirus
  • McAfee
  • Kaspersky Anti-Virus
  • BitDefender Antivirus

Antivirus programs and How they work

Antivirus programs are computer software used to identify and remove computer viruses, as well as many other types of harmful computer software, collectively referred to as malware. Antivirus programs start working when you turn on your computer. They inspect your computer's memory to make sure that no virus is present before the computer starts opening more files. When an antivirus program detects malware it prevents the program from running and instantly notifies the user about the danger of running the program. Furthermore, it asks for the user's permission to disinfect the program or delete it.

Antivirus programs work in two methods. First, they compare data on your disk with virus definitions, signatures and updates (samples of infected code). If the data matches with any virus signatures, then the program concludes that the file is infected by a virus. Every virus has a unique signature. Some of the common antivirus programs like Norton Anti-Virus contain more than 63,000 virus signatures.

Other methods of scrutinizing data are “Heuristic scanning” and “Sandboxing.” This process consists of looking for dangerous activity patterns. It looks through the lines of code in a program and tries to figure out if it's malicious. The antivirus program then tries to ascertain whether or not the program contains the virus by looking at how the program is created and acts. Sandboxing is when an antivirus program takes the suspicious code and runs it in a Virtual Machine (secure from the rest of the system) so as to figure out exactly how the code works and what its objective is. Antivirus companies also use these two scanning methods to construct new virus signatures.

Most antivirus programs have two modes of virus scanning, active scans and complete scans. An active scan goes through important and frequently used files and folders and typically takes 3-5 minutes. On the other hand, complete scans do thorough analysis and inspection of the entire computer. This usually takes 30-45 minutes to complete, but on some computers it may take several hours. It is recommended to run a complete scan at least once a week.

Proper utilization of Antivirus software

As many viruses are created daily it is important to update your antivirus software regularly. You should also enable automatic scanning of files before opening them. Additionally, antivirus software should be allowed to scan all downloaded files before installing or running them. Sometimes it becomes tedious when your antivirus software asks your permission to run other programs. However, it is not a good idea to disable it. Computers can get infected any time through any media whether it's Internet, email or external storage.

External related links