4.6 COMPUTER VIRUS

 The world of computers and Information Technology is going through an era of electronic terrorism, in the form of virus. It is a problem that is potentially so dangerous that it threatens the proper functioning of the computer system in today information usage. 

We need protection from viruses, because they destroy the contents of a file or a directory. Viruses copy themselves to other disks to spread to other computers. They can be less harmful and just eating up machine time or they can be vastly destructive to your files. There are more than thousands viruses known till today. Some of the category of them are given as:

1. Trojans: This virus hides inside something else to sneak in unwanted programs. You don’t know that they are there, like the famous Trojan horse. These often capture the login and password of your computer.

2. Worms: These are unwanted programs that are transferred over network or Internet connections to your system and spread themselves quickly into your computer.

3. Spy ware : Spyware programs sneak on your computer to steal important information, like your passwords and logins and other personal identification information and then send it off to someone else.

4. Zombie : These programs take control of your computer and use Internet connection to attack other computers or networks or to perform criminal activities.

5. Phishing : Pronounced like the word ‘fishing’ is a message that tries to trick you into providing information like your social security number or bank account information or logon and password for a web site. The message may claim that if you do not click on the link in the message and log onto a financial web site then your account will be blocked, or some thing similar to this message.

6. Spam : It is email that you did not request and do not want. Spam of one person may be another’s useful newsletter or sale advertisement. Spam is a common way to spread viruses such as Trojans, Black Friday etc. into other person’s computer.

7. Browser hijacking: Hijacking occurs when one of the nastiest takes control of your browser, sending you to sites that you did not mean to go to. This may be a porn site or it may look like a real banking, sales, or credit card site. The purpose of this is to steal your personal and financial information.

4.6.1 How to protect your computer from viruses

To protect computers from unauthorised access firewalls are used. A firewall is an integrated collection of security measures designed to prevent unauthorized electronic access to a network computer. To protect your computer from unauthorized access, viruses and spam you need to install antiviruses and firewalls to your computer system.

Firewalls are frequently used to prevent unauthorized internet users from accessing private networks connected to internet. All messages entering or leaving to network are passed through the firewall, which examines each message, and blocks those which do not meet the specified security criteria.

Figure 9 shows the concept of working of firewalls. In Figure9 those systems which are directly connected with the internet are not secure and chances of virus infections in them are very high. But systems which are protected with firewalls are very secure and data stored in them is safe from the attack of viruses.

In case of virus attack on a system, it is always advisable to follow the dictum “Prevention is better than cure”. Viruses are not omnipotent. They can be cured by using antiviral programs. Functions of antivirus  programs are:

  • · Prevention
  • · Detection
  • · Vaccination
  • · Identification, and
  • · Damage control

Example of some antivirus and prevention software programs are: Norton AntiVirus, Mcafee Antivirus, Quick heal Antivirus, Avast Antivirus and firewalls. Remember that firewall is security software which acts as logical wall around your computer and blocks unauthorized access attempts to your computer.

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