Best AntiVirus Software

What is Computer Virus?

Computer virus - A parasitic program written intentionally to enter a computer without the user's permission or knowledge. The word parasitic is used because a virus attaches to files or boot sectors and replicates itself, thus continuing to spread. Though some viruses do little but replicate, others can cause serious damage or affect program and system performance. A virus should never be assumed harmless and left on a system." -- Symantec

Many people are confused about different types of computer virus. The term computer virus is often used broadly to cover several types of malicious programs, including viruses, worms and Trojan horses.  Each of them shares some similarities and some subtle differences.

Different types of computer viruses

Computer viruses are parasitic programs that can replicate and spread to other computers.  Computer virus needs a host program to run, so it often attaches itself to executable files.  The virus codes run once you open the executive files.  Computer viruses are spread by sharing infected files or email attachments. They can remain hidden in the system and are unleashed at a fixed date and time. Computer virus causes mild to severe damage to boot sector, hardware, computer programs and data files.  Depending on their actions, they can be further divided into boot viruses, program viruses, macro viruses etc.

Computer worms can also replicate themselves, but unlike computer viruses, worms are self-contained.  They can run and spread without being part of a host program. Worms spread at enormous speed in the network. Hundreds or thousands of copies can be sent to everyone in your email address book and the process repeats itself in the receiver's computer.  Computer worms use up system or network resources quickly, causing the system or network to stop responding.  Due to the similarity of computer worms and computer viruses, computer worms are sometimes considered as one type of computer viruses.

Trojan horses are malicious programs in disguise as some useful or innocent programs. This tricks you into running the programs. Sometimes, Trojan horses are hidden codes embedded within a legitimate program.  Trojan horses are run without your knowledge, they can damage your files or create security leak in your system, allowing unauthorized users to access your computer.  Unlike viruses and worms, they usually do not replicate themselves.

Computer viruses, computer worms and Trojan horses are all malicious programs.  Even though they have different modes of replication and action, all of them are extremely destructive.

How to choose the best antivirus software?

The number of new computer viruses is rising every year and they are getting more malicious than before. In 2003, 7 new viruses were unleashed every day. In 2004, more than 10,000 new computer viruses were identified, many of them have several variants. Computer viruses, computer worms and Trojan horses spread through the network by sharing diskettes, downloading files from the internet and email attachments. To protect your computer, always use the best antivirus software from reputable publishers and update it regularly.  Do not open suspicious files or attachments even if they come from people in your address book. 

The Best AntiVirus Software usually have several characteristics:

1) They come from well known reputable publishers.  Be wary if you have never heard of the name of the antivirus programs or the software publishers. Do not run any free downloads or free scans unless you have researched about the software publishers.

Installing a poorly designed program or one which is accompanied by hidden applications (such as spyware/adware) will do more harm than good to your computer.  They may damage your system, create security holes and give you a false sense of security. 

2) The software are user friendly, i.e. they are easy to install and easy to use. 

3) They provide rich features, including real time protection, stopping computer viruses, worms and Trojan horses before they infect the computer, scanning of incoming and outgoing email, instant messages, and employing advanced worm stopping and script stopping technology.

4) The software publishers update their detection database frequently and release new version regularly. The antivirus software should have the option of automatic update. 

5) Provide good and prompt technical support, such as live message, email and phone support.

Computer viruses are just one of the IT security problems, hackers and spyware / adware are two other major threats.  Although antivirus programs can now detect and remove some spyware programs, they cannot stop hacker attacks, nor can they detect most of the spyware programs which are usually installed with other applications or free downloads.