The spyware itself does not direct infect the spread of the worm or virus released into your computer. An infected system does not release the infection to other computers. The spyware goes through the system deceiving user the software weak spots. It is most commonly known that spyware is installed without the user’s permission. Users will not install software if they know it is going to corrupt their computers, the spyware actually piggybacks on a piece of software and then tricks the system into loading it onto the hard drive.
The makers of spyware are not calling their product spyware because only hackers would buy it. They present as some thing along the line as a web accelerator or helpful software. The user will then down load and then release the virus. The spyware can also infect a computer by something called shareware or any other type of software that is downloadable. Another way to infect a computer is through a pop up, some of those pop ups you see are not just advertisement, they carry worms and viruses. Try not to click on the pop up, no matter how attractive the offer may be.
Spyware is very complex, as you can see there are many ways for it to infiltrate your security on your computer. Only use reputable software, do not click on pop ups and plain old be careful, if a website is not secure do not enter any of your personal information. Try to stay on reputable websites as well.