Types of computer viruses

What are the major types of computer viruses? What do we mean when we say computer virus? How do we secure our data and information and prevent continuously from the possible virus or malware attack? We will try to answer these questions in this article.

Usually people refer all these destructive programs as a virus; however, there are other software programs such as spyware and Trojans capable of destroying data from a computer.

Here are the essentials we should be aware of about computer virus and its prevention methods.

But first let us answer this question:-

What is a computer virus?

To put it simply, computer virus is a computer program capable of attaching itself to a disk, file or program. It then replicates itself. This happens without the knowledge of a user.

A virus can infect and damage computer systems and files. Virus has several behaviors or variants. Variant is a modified version of a virus, usually difficult to remove it like the original one. Some virus resides in a computer’s memory and triggers when a program or file loads. And other type of virus will fill a computer with annoying messages.

Other types of computer viruses

Worms are the other destructive parasitic computer program which like a virus replicates itself. This virus copies itself on the same computer and sends copies to other computers via a network.

Worms can easily transfer through an email that comes with attachment. The attachments may have .exe, .scr, .zip extensions. You need to beware of those kinds of attachments. If it is opened, it executes itself and spread throughout a computer and entire network.

Worms are responsible for sluggish computer, it fills the computer memory until it fills and there won’t be enough space to open file or load programs.

Trojan horse is another program which behaves as if it is a useful application but it performs something the user doesn’t expect. Trojan doesn’t replicate itself. Trojans are used to steal passwords and logon details, usually from bank customers to gain access to their credit card information and other confidential data.

Spyware is also a type of software capable of infecting computer systems the same way as a virus. The purpose of spyware is to send information (such as identity theft) from your computer to the creator. Most anti-virus programs include anti-spyware application.

Keyboard loggers is a kind of code which monitor the key pressed on a keyboard and send this information back to the author. It is used to steal password and other information.

How viruses enter a computer system?

Definitely, a virus enters into a computer system from outside.

Here are the ways that open a door for system infection.

  • Email attachments
  • External devices such as portable hard disk, flash memory, floppy disk
  • Internet downloads
  • Cracked or pirated software

How to prevent virus attack?

The following are good practices to protect your computer from viruses. It helps to guard your computer from all types of computer viruses.

  • Install anti-virus programs and update on regular basis. Most anti-virus applications have daily, weekly and monthly update definitions.
  • Try to reduce using external disks, specially other people’s disk
  • Don’t open e-mails with attachments from unknown sender. Even you should take care if you receive it from one of the mail lists.
  • Do not download programs from sites you don’t know and trust - Always scan any external disks before copying or installing from them
  • Always backup your files to other medias
  • Be alert for new threats and protection methods

List of some of the most popular anti-virus programs

If updated regularly almost all types of computer viruses can be removed using the following anti-virus programs.

  • Symantec Anti-virus
  • McAfee Virus scan
  • Kaspersky Anti-virus
  • Avira Anti-virus
  • Avast Anti-virus
  • AVG Anti-virus
  • Panda Anti-virus
  • F-secure
  • eScan (recently developed anti-virus)


So far we have tried to discuss the types of computer viruses and the effect they pose on computer systems. We also saw the preventive measures we should take to secure digital data from possible virus attack.

I believe you have got some helpful information about computer virus from this article.

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