Chances are that when you discover Spyware on your computer the first question that springs to mind is not “what is this exactly?”, nor “what does it do”, but “how did that get there?”.

Spyware programs have an incredible ability of disguising themselves. Even the most experienced system administrators or programmers end up with spyware on their computer. It's not their fault: the ways spyware gets on your computer are very creative, and it's almost impossible to close all the ways of access. But which are these ways of access?

The earliest one, and unsurprisingly still the most common one, is having the user install a program they do not even suspect to contain spyware. This can come in the form of a program that stores or generates password, a browser add-on or anything of that kind, which actually does what it says on the box. A famous example was Kazaa Media Desktop, a peer-to-peer program that used to be very popular a few years ago. Kazaa was a really good P2P client and had a thriving community, but it also had spyware. For a long time, users didn't suspect that such a useful program could even contain spyware, even though it was quite obvious.

Slightly similar to this method is the case when spyware is installed automatically, often without warning, when you install another program. This involves the installation program installing not just the software it was supposed to install, but also a couple of “bonuses”, about which the user is not notified. In some cases, in fact, the user is notified: the installation program claims that installing additional software may give you some special benefits, or improve your experience, but all they do is spy on you.

These two methods are very popular today, and very efficient, because users have the habit of not reading through their messages. Installing a program is usually a case of clicking Next until the Next button is replaced by a Finish button. Simple, but in some cases, very harmful.

More recently, a number of new techniques have emerged. These techniques make use of various vulnerabilities in application or system software to crawl onto an user's computer, much like worms do. These are quite rare today, in fact, most experts do not even consider these to be forms of spyware, but rather worms.

Another common technique is that of false “automatic updates”. Nowadays it's common for software to offer the facility of automatically checking for updates, retrieving and installing new ones. A malicious program would simply start as a useful program that does its job, but which brings some uninvited guests when updated. The morale of the story? Always check what a program's automatic updating function really does.

As you can see, all of these spreading methods have a common denominator: they are very hard to spot per se. Spyware can be installed just like any other program, and looks just like any other program. It's not how it looks on the outside that makes it suspicious, it's what it does and what it looks like on the inside. This is why very advanced detection algorithms are required, like those employed by XoftSpySE. It is very difficult to spot spyware upon entering your computer. The real proof comes after the installation, upon your anti-spyware program's first scan.

The important part about how spyware spreads is that you can actually help it stop. I'm not just talking about using anti-spyware software, anti-spyware programs such as XoftSpySE will do their job regardless of what you do. I am simply talking about adopting a more vigilant posture. If an installation program is making you a special offer, think it through and run a Google search. You can always come back to it if you need to. If a program is known to include spyware, don't use it, regardless of how useful it may be. Chances are there is at least one spyware-free alternative to it. All these can help prevent spyware from spreading, and with enough users doing so, spyware may eventually become extinct. Until then, however, your best bet stands in anti-spyware programs like XoftSpySE.

Drew specialises in computer security and optimisation. To read his reviews on the top five anti-spyware programs visit http://www.top5-anti-spyware.com