The worst thing about spyware silently cohabitating on your computer isn t just how long it s been there or what it s been up to, but figuring out how the program landed on your computer in the first place. Where does this stuff come from?

Just like weeds silently clinging to your socks as you a stroll through the woods, spyware attaches itself to your computer like a hitchhiking stowaway when you casually surf online. But before something can be installed on your computer you usually have to click on or open some object or program. Below are a few of the most common methods used to trick you into installing spyware:

  • Opening spam email
  • Clicking on deceptive popups
  • Downloading free utilities, games, toolbars, media players, etc.
  • File sharing programs
  • Visiting corrupt websites
  • Mainstream software applications

While there is plenty of content available on the Internet that is not designed to covertly watch your actions, there are many freebees and even over-the-counter software that come quietly bundled with spyware. Spyware not only gives advertisers an inside look at what interests you online, it can lead to disclosure of sensitive personal data as well. Here s how spyware ends up on your hard drive and what you can do to prevent it.

First, one of the biggest mistakes you can make before you surf the web is to have your surfing security settings too low. A low security setting allows cookies and spyware programs to easily be stored in your computer memory. A few things that you can do in order to keep spyware off your computer include setting your Internet security at the default level or higher, scrutinizing what you download, keeping current on operating systems updates, and finally, installing anti-spyware software on your computer to catch all that you miss. Anti-spyware will locate, quarantine then delete spyware that your computer unwittingly accepts.

Next, follow your instincts. If the source doesn t seem familiar or trustworthy, don t open the email, click the popup, or visit the site. Get your utilities from a source you trust. sometimes the free ones are not worth the price you pay in headaches. Look for a motive when you see an enticing offer. Why would anyone want to offer you regular, free  atomic clock updates  for your computer, anyway? Don t fall for it.

Learn from others online exactly which software harbors spyware. It only takes a second to run a search and find out what other users are saying about annoying spy-packed software, including file sharing programs (such as Kazaa and BearShare) and even mainstream software applications. In the later case, a large group of voices protesting spyware can have an impact. For example, one popular tax preparation program recently included spyware with its product in order to prevent any copying of its files, even for legal purposes like backups or for use by members of the same household. But customers were edgy and annoyed that their tax software would have the ability to keep such a close eye on their behavior and protested (loudly) to the manufacturer and all over the Internet. The software company listened and the next year their product sold without the intrusive, built-in spyware.

Because you d say no, spyware installers don t bother to ask your permission. Many feel whatever they can get from you no matter what the method is fair game. Some marketers use cheap tricks to install their spyware on your computer. For example, there is a piece of software known as Gator that attempts to trick you into installing their product through an enticing popup ad. Once you say  no  to the download invitation, a second popup ad appears and asks:  Are you sure?  This ambiguous yes/no question leads people to answer with a click that initiates a download they do not want and are not aware of.

Another method that lands spyware on your computer is called a drive-by download. When you visit a given website you see a popup asking your permission to download an application, the tone of the message causes you to believe that the download is required to view the opening webpage even if it isn t. If you click  yes  spyware is downloaded to your computer. But if you click  no  popups appear on subsequent pages until you are tricked into clicking on one of them and ending up with spyware operating quietly in the background.

Some companies use a form of spyware called adware to gather information in order to study consumers  Internet surfing habits; they then use or sell the data to other companies. Once the adware is installed on your computer through one of the methods mentioned above, the spyware triggers popup ads targeted at your perceived interests. You end up giving away both your personal preferences and your computer resources (your Internet connection bandwidth and computer processing time) while getting nothing in return but a barrage of advertisements and "if the spyware successfully retrieved your email addresses" spam. To learn about more aggressive types of spyware that might end up on your computer, read What Types of Spyware are Out There?

Because new methods of contaminating your computer with spyware are constantly being developed, consider installing anti-spyware software. This software is designed to detect and yank out all spyware before it causes you pain. Nothing can quietly slip onto your hard drive again if you use anti-spyware as a guard dog to alert you to unauthorized, unannounced downloads.

Spyware is annoying and can lead to some serious headaches. If you take appropriate precautions you can avoid troubles and keep your PC clean.

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