Antivirus program (software), as the name suggests, repels virus in a computer. For a broader explanation, an antivirus program detects, prevents and removes the harmful (malware) software from your computer. Traditional antivirus programs just removed computer viruses. However, modern antivirus programs protect you from more than just that. Browser hijackers, keyloggers, rootkits, backdoors, Trojan horses, and worms are just some of the several different examples of malicious software that modern antivirus protects you from.

The first-ever antivirus software was created in 1987, and ever since then, antivirus programs have grown alongside the viruses. Antivirus programs are all created with algorithms, which is why they aren’t perfect, as no algorithm can perfectly detect all the viruses in the world. However, several layers of protection and detection still do a pretty good job of eliminating most of the malware.

Here are some of the methods that antivirus programs use to identify the viruses:

  • Signature-based detection: This is what antivirus programs heavily relied on. When an antivirus firm discovers a new malware, they extract its signature and add it to the antivirus software’s database. Later, when scanning for viruses, the program tries to match the malware’s signature to the one that it already contains in its database. If it matches the signatures in its database, the software then proceeds to eliminate the problem.
  • Heuristic-based detection: Used alongside the signature-based detection technique, heuristics go to the root of the virus’s family to detect it. There is always that one common genetic signature in a virus family and heuristics uses that common point to detect the virus, even if it is covered in a layer of other meaningless codes.
  • Behavioral-based detection: This is similar to the heuristics, however, instead of following a common genetic root; it looks into the behavioral blueprint of the virus. That way, the virus can be detected easily, even if it has not been introduced to the database before.

As amazing and interesting as antivirus programs may seem, they have their cons as well, which include:

  • Renewal costs: A reason why some people may not want to opt for an antivirus software. Some antivirus programs automatically renew your subscription, Norton AntiVirus, for instance, automatically renews a subscriber’s subscription without any prior warning.
  • Rogue antivirus programs: There are many fakes out there, so you have to be careful when choosing your antivirus software. MS Antivirus, MAC Defender, and WinFixer are examples of rogue security programs.
  • False alarms: This occurs when an antivirus program detects something that is non-malicious as a virus. This can cause a serious problem, for example, if an essential file is detected as a malicious software, it could cause the operating system in Windows to stop working.
  • Effectiveness: Studies have shown that the effectiveness of antivirus programs has recently gone down. It isn’t particularly the antivirus software’s fault, as modern viruses are created by professionals and hence, are harder to eliminate. Also, antivirus programs aren’t always effective against new viruses.

That said, it is still better to have an antivirus program than to have none at all.