Many applications that you download off the Internet could be wolves in sheep's clothing! Spyware, malware, or adware refers to the class of software, which are normally installed without the full knowledge of the user; they embed themselves in the IE browser or at system starup in order to monitor browsing habits, suck up your bandwidth, act as a backdoor for advertising and pop-ups, re-route the user's browser, and even even log personal information llike passwords and keystrokes. They ruin the Internet experience, and cause nothing but misery.

They are worse than viruses, but they not self-replicating. Most often, they are installed with the user's permission (though not their knowledge), they are not normally detected and rooted out an anti-virus software. There are generally two methods by which spyware can infect a PC.

The most common method of spyware infection is when a user installs an ad supported freeware application. This is not to say that freeware sucks, most ad-supported applications are harmless, and do nothing more than have an extra banner in the application. The free versions of the Eudora email client and the Opera Web browser fall into this category. But many applications use external advertising systems, which will run at all times, whether the application is in use or not. Known sources of malicious adware include:

File-Sharing Apps: