The digital technology specifically, the internet has led to the dawn of intercommunication. With just a click of a button, mails can be sent thousands of miles in a matter of seconds. The ever increasing use of Internet means we now have access to quantity and quality of information as never before. This also means that more and more computers can be accessed by others through file transfers, e-mails and websites, leaving them susceptible to infection from an increasing number of malwares.

What is a Malware?

A Malware is an abbreviated term used to describe a "malicious software" program; software designed to infiltrate or damage a computer system without the owner's informed consent. It is also an expression generally used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code. Malware includes things like spyware or adware programs, Trojan horses, computer viruses and computer worms.
Spyware/Adware (Advertising-supported software) is a computer software that secretly monitors the user's behavior without the users informed consent and collects various types of personal information, such as Internet surfing habit. It also interferes with users’ control of the computer, such as installing additional software, redirecting Web browser activity, accessing websites blindly and can even change computer settings, resulting in slow connection speeds, different home pages, and loss of Internet or other programs.

The Trojan horse, at first glance will appear to be a useful software but will actually do damage once installed or run on your computer. When activated, it can change your desktop, add silly active desktop icon and can cause serious damage by deleting files and destroying information on your system. It is also known to create a backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised.

Virus is a computer program that can copy itself and infect a computer, but can only spread from one computer to another when its host is taken to the uninfected computer. A virus attaches itself to a program or file, leaving infections as it travels (corrupting or modifying files, damaging programs, reformatting the hard disk). Viruses cannot be spread without a human action, which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious program.

A ’computer worm’ is similar to a computer virus by design and is considered to be a sub-class of a virus. But unlike a virus, it has the capability to travel without any human action and replicates itself on the system. Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much system memory/network bandwidth, causing Web servers, network servers and individual computers to stop responding.

Primary indicators that a computer may be infected:

• The computer runs slower than usual
• The computer stops responding, or it locks up frequently
• The computer crashes, and then it restarts every few minutes
• The computer restarts on its own. Additionally, the computer does not run as usual
• Applications on the computer do not work correctly
• Disks or disk drives are inaccessible
• You see unusual error messages
• You see distorted menus and dialog boxes
• The is a double extension on an attachment that you recently opened such a .jpg, .vbs, .gif, .exe extension
• An antivirus program is disabled for no reason. Additionally, the antivirus program cannot be restarted.
• An antivirus program cannot be installed on the computer, or the antivirus program will not run.
• New icons appear on the desktop that you did not put there, or the icons are not associated with any recently installed programs.
• Strange sounds or music plays from the speakers unexpectedly.
• A program disappears from the computer even though you did not intentionally remove the program.

How to avoid Malware:

• Don't click e-mail attachments. Even if you know the person who sent the email beware of attachments. Many computers with infections will send out email to everyone on their address book without the owner ever being aware.
• Don’t use file sharing applications and don’t run programs of unknown origins.
• If you get pop-ups when opening a web page, don’t click inside the pop-up to close it. Always click the red “x” in the upper right corner. The “cancel” or “close” button in the pop-up might have unintended effects.
  
• If you get a message from your computer warning you that it is infected and you need to download such and such software to remove the virus, don’t do it. Downloading the fake virus remover will only make it worse. No legitimate software ever uses this tactic.
  
• Avoid free downloads unless you are absolutely sure you can trust the source. Often these freebies are packaged with a good deal of adware, so be careful.
• Start practicing safe web viewing.
• Disable hidden filename extensions.
• Keep all applications (including your operating system) patched/up-to-date.
• Disable Java, JavaScript, and ActiveX if possible.
• Disable scripting features in email programs.
• Turn off file and printer sharing on the computer.
• Install a personal firewall on the computer.
• Install anti-virus and anti-spyware software and ensure that it scans all email attachments and it is configured to automatically update when you are connected to the Internet.
  

The Internet is a huge resource for those of us who are curious. Our main goal is to satisfy this curiosity that somehow leads us in developing a conditioned response to “just click” which exposed us on such consequences.

Think before you click, consider the potential consequences. The real trick in running a clean computer is to avoid exposing yourself to them. Good common sense will keep your computer safer than whatever virus protection you have installed.

In the final analysis, you and you alone are the best line of defense against malware infecting your computer. so again before CLICKING, THINK!

http://support.microsoft.com/kb/129972
http://ezinearticles.com/?How-to-Avoid-Malware-on-Your-Computer&id=466044