?A large arrow points to search field when i press shift key???

Hello! For some unknown reason a large ouline of a shadowed arrow pointing up about an inch below the menu bar on the left side. Also, if I hit command shift it makes an outline of the command symbol appear, just like the arrow. It appears when i use any of my browsers or programs, text edit, finder, etc... I am concerned it may be a virus, trojan or worm! I have run Disc Utility and iAntivirus. Anyone have any idea what is going on? All help is greatly appreciated!