I don't know about a malicious script but have you tried a new mouse and/or reinstalling the mouse driver?
I had same problems with several pc's. The mouse went bad - left click was shorted and acting as if you were continuously clicking it, so as it is dragged any link or active spot would respond as if you clicked or double clicked.
If you do not have a new mouse to try one method i used to diagnose the problem was to swap right click and left click functions in control panel.
Just athought and it might help you with your problem