Spyware

Spyware is software that allows advertisers or hackers to obtain sensitive information without being noticed by the victims.

Problems caused:
Because it is not easy to know, spyware is often used to steal valuable data from computer users. If you have this, do not be surprised if suddenly passwords, ATM pin numbers, credit card numbers and other sudden changes hands.

Prevention / neutralization:
A system could be infected with spyware just by visiting certain web sites (which is dangerous). Some sites that contain spyware will require the installation of applications through a window pop up. Tpai there is also a direct install themselves without permission.

To avoid this make sure the browser used to surf the Internet already has a reporting system to malicious sites. Browsers like Internet Explorer 8, Firefox (with NoScript plugin), Google Chrome, and Opera already provides this facility.

from : http://www.infokomputer.com