PestTrap w/a Hijacker...

Can a hijacker scan or download your dekstop files? A few days ago I contracted PestTrap, but tried to immediately get rid of it with HijackThis & Adaware. It worked to a certain extent, but the next day my desktop files were highlighted when I turned on my computer and when I logged onto the net a different color screen would appear behind my browser on my desktop. However, my computer & internet ran at regular speed. A couple days later I downloaded AOL security system, and it seems to have gotten rid of it. No more red X's in the bottom corner of my screen or balloons with "You Have Spyware!" & no more colored screen behind my browser. However, when I ran AOL security for the first time, it did revealed a Hijacker along with all the other trash like PestTrap, etc. I seem to have deleted them all. So, do you think a Hijacker came in along with PestTrap? Thanks for any onfo.