The Anti-virus software is a kind of software that protects your computer from all kinds of malicious programs that enter your computer without your consent. Such malicious programs are intrusive, hostile, and annoying. The different types of malicious programs can be:
- Computer virus: This is a kind of hostile program acts similar to the virus that infects humans. As soon as it enters your computer, it sits quietly till it finds executable software that helps it to spread. It actively transmits itself over all the computers that are connected on the network and destroys your important software.
- Worm: This hostile program is quite similar to virus but it does not need an executable to spread it. It spreads automatically and destroys all important software.
- Trojan horse: This hostile program conceals itself under other useful programs and invites the user to run it. As soon as it executes, it starts deleting the user’s files and starts installing other malicious software.
- Spyware: This harmful program is quite different from viruses and Trojans but is equally harmful. It does not spread like virus but it keeps giving annoying pop-ups to lure you to install its paid version that treacherously claim to protect your computer. This software secretly collect private information such as credit card information, social security number, and user names and passwords from your computer and sends them to remote computers.
- Adware: This software is somewhat similar to spyware but its main purpose is advertisement. They may not be considered malicious software because it comes on your computer with your consent. However, it may hit you with a barrage of advertisements; from pop-ups to banner ads.
- Grayware: This software term is used broadly for all computer programs that are annoying but not necessarily totally destructive. It includes programs such as adware, joke programs, and dialers.
The anti-virus software needs to be updated with latest anti-virus definition to keep protecting your computer with the latest malicious programs. Most anti-virus software can be set to update automatically, as shown in Figure 3:
The anti-virus software is now a requirement of every computer/server that is either inter-connected on a network or connected through Internet. Even a standalone computer needs anti-virus software to be installed. This is because the virus can not only infect your computer through Internet but can also infect your computer from external storage devices connected to your computer temporarily. Some important firewall software are: AVG, Avira, Malware bytes, Norton, and Combofix.