These programs use tricks to get you to download and pay for there software. Here is an example:
Typically, you can get infected by going to malicious porn sites. They make you download a video codec to watch the video. When you download the codec, you get infected.
In 2004, i became interested in computers and security. I volunteer a lot of my time helping others at various security sites Malwarebytes, Spywarehammer and TechSupportGuy. Hope you enjoy my blog, i look forward to any replies.