This time I have decided to write about computer viruses. There are a number of people who hear this word very often but do not have much idea about the same. So, this is an effort to give them a small idea of what a Virus is in a very simple language.
To start with, a virus is a small piece of code(or a small program) which is designed to do some harm to a computer system. For example, deleting important files from the system. The virus can replicate itself and affect other machines as well. So, its a kind of infection which harms your computer and also other computers depending upon its type. Now, this infection to your computer can be caused by some other breed of programs also (Virus is one of them). Following is some detail on the kind on infections:
1) Virus :As discussed above, it is a small piece of code that harms your computer but to reach a system it requires a carrier. It piggybacks on a carrier(generally a safe computer program) and then infect your machine when you run the carrier program. The carrier program can be a spreadsheet program. When you run spreadsheet then the virus also gets executed and can attach to other programs. Just imagine the scenario when most of the programs on your system have an attached virus!! Well, it’ll leave your systems unusable.
2) Trojan horses :This is also a small program which deceive you by showing that they are performing a particular task which you want but actually harm your computer behind the scene. For example, it can be a small game which you play with a lot of interest but might be erasing your hard disk simultaneously. Trojan’s do not replicate by themselves.
3) E-mail viruses :An email virus spread through e mails. The virus attaches itself to e mail and travel with it. If you open the attachment then it again replicate and send itself to for example first 100 e mail addresses from your address book. This is a very fast way to spread infection. After infecting a system it can do damage to the system in multiple ways depending upon the way these are programmed.
4) Worms :This also is a piece of code(or program) which keeps on scanning a network for replicating to other machines. Once it finds any security hole, it infects that system also. In other words it doesn’t require any carrier to replicate. It is an independent application that can replicate itself. Once it infects a computer it can copy itself in various folders, create new files and registry entries in the system etc.
5) Spywares :This is also a different breed of infection that can infect your computer. I had a very nasty experience when my computer got infected with spyware. Just want to share the experience in brief. One fine day I switched on my laptop and got really annoyed with its speed. The speed was dead slow. It was taking very long time for a simple file to open. Be it a word document or the browser itself (IE). To make the situation worse, as the browser opens (after years) multiple web pages web pages were opened automatically. One of the bugging web page claimed to be a tool to remove spyware and I clicked OK. The problem persisted even after completing the scan. The web pages kept on appearing repeatedly. At that time I was not sure what happened but was told by one of my friend that my system is infected by spywares. Afterwards I installed an antispyware and the problem got resolved. I think, from my above experience you are now aware of what a spyware can do.These are specially written piece of code which makes computer user experience reeeallly bad. Above is a little explanation of the kind of annoying problems caused by spyware.
6) adwares : Also known as advertising-supported software, is any software package which automatically plays, lays, displays, or downloads advertisements to a computer after the software is installed on it or while the application is being used. The programmers of the software deliberately add a piece of code which is responcible for displaying adds. Actually these are not Viruses which harms your computer(provided the origin is genuine software) but silently track your browsing, personal information etc without your knowledge. Developers of the softwares justify the idea of adding adware beause it helps them in reducing the overall development cost of the software thus creating a good user base. Still, I would recommend you to remove any adware which your antivirus/antispyware program reports.
This is a vast field and I might be short in the explanation but you can always refer specific books for more detailed information.
Now coming to protection part(how to protect your computer from infections), you can protect your computer from infections by taking care of very simple things as mentioned below :
1) First and most important of all, install an effective antivirus and antispyware. You can also opt for a complete internet security suit like Bitdefender internet security or Kaspersky internet security etc. Internet security suit is a complete package consisting of antivirus, antispyware and a firewall. There is no replacement for these softwares and you must have one.
2) Never ever double clickon an unknown e mail attachment that contains an executable file. For example files with extension .EXE, .COM, .VBS.
3) Make sure that Macro Virus Protection is enabled in Microsoft applications.
4) Keep updating your operation system and other applications(Microsoft word, excel etc) with latest security patches.
By following these simple steps you will remain protected from infections. If your system is infected then you can download ‘Superantispyware’ absolutely free from http://superantispyware.com/download.html. Free version doesn’t offer you real time protection but it is a very good free antispyware software which will definitely remove existing spywares, adwares, trojans, worms etc from your system. Why I am so sure about this? Well, because me too is using it for the past 1 year :). Believe me friends, its worth trying.
Wish you a safe computing.