Protect Your PC By Spyware and adware

In Lesson 1, you learned that viruses, worms, and Trojan horses are programs designed to carry out malicious activity on your PC. You also learned that viruses and worms are capable of replicating automatically and spreading from system to system. In this lesson, you will learn about adware and spyware. 
Adware is an application installed onto a PC without the user's knowledge. These apps have a single purpose: To deliver ads to the user. This is a deliberate business model because the people behind the adware are paid to pipe ads to users who unwittingly host adware on their PCs. Technically, adware is more of a nuisance than malicious, but it can cause system crashes because it makes PCs unstable. 
Spyware is a different matter. This type of application is designed to spy on you. It might spy on your Internet surfing habits or collect information from your computer about your identity, your credit card numbers, or your passwords. Spyware is particularly bad because it can capture all sorts of data and send this back to criminals who can use it to steal your money or identity. 

As a rule, the most common sources of adware and spyware are low-quality, dubious Web sites (for example, sites that deal in pirated software or music). Most adware and spyware is installed by either tricking the user to click something and install an application or by exploiting a flaw in the browser or operating system. 

If you want to get the best from your PC, you don't want to have adware or spyware running on it. Many antivirus packages (for example, Norton AntiVirus 2008, McAfee or ZoneAlarm) can detect and remove certain adware and spyware, but it's best to have a separate program to look for and remove these unwanted PC pests. 

 
Microsoft Windows Defender scanning a PC for spyware and adware.

A number of free applications are available for you to choose from. One is called Windows Defender and is available from Microsoft. Another good program to install and scan with on a regular basis is called Ad-Aware by Lavasoft. You can install both of these on your system, having Windows Defender running all the time and using the latest Ad-Aware to scan your system daily (if you are security conscious) or weekly to check for and remove anything that might have managed to sneak by Windows Defender. 

 
Ad-Aware from Lavasoft is a good spyware and adware scanner.

Another thing you should do if you are running Windows XP is to make sure that you have installed Service Pack 2 (also known as SP2). Many of the exploits that adware and spyware use to install themselves on PCs without the user's knowledge have been patched in SP2. Visit Microsoft's site and install all the patches your operating system needs.