Rogue Anti Spyware Programs
The following link takes you to SpywareWarrier and is a list of 184 anti spyware products that do not do what they advertise.
http://www.spywarewarrior.com/rogue_...re.htm#sh_note
These programs supposedly help you fight spyware. They do not. So in addition to malware you have to consider these also.
And all of this keeps compounding and getting more sophisticated.
The important point is not to let it overpower you.
To repeat Rule #1 of Safe Computing.
If you do not know what it is when a window (web page) opens up do not open it.
These people that originate this junk count on others being curious.