MaFia JaK
--Yes, it is true that parasites, spyware, etc. download with many programs from the Internet. Usually they are "free" programs. Kazaa would be one the more famous examples. The spyware is the price you pay. And sadly there are a few peripheral makers, that also deposit spyware when you install the equipment you have paid for!
I did not read all the articles in that reference, but one thing you can do before you download "free" programs from the net, is to check out what this site says about the "free" program.
http://www.spychecker.com/
The info is not always up to date or inclusive, but it is a start.
Can the spyware remain undetected? It usually is undetectable when you download the program. It might be detected when you scan (as you should) the downloaded setuup file with antivirus before the installation. But often you will learn only after you are infected, since antivirus programs are really not set up to detect spyware other than viruses.
Will HiJackThis find the spyware? Well, HJT really does not "find" spyware, in the sense that it does not highlight what is and what is not spyware. It generates a log that tells you what programs are running, what ActiveX controls are on your PC, what your home page and search pages are, etc. If you know how to interpret an HJT log, you probably can find whatever spyware is on the PC. But interpretation takes practice and study. VirtualDr has an HJT forum where you can post HJT logs for others to interpret.
I would rather suggest as first steps the info here
http://discussions.virtualdr.com/sho...hreadid=167915
and especially run AdAware or SpybotS&D first. They will tell you what spyware is on your PC as long as it is in their data banks.