Unknown Light on Dash on 2009 Chevrolet Malibu

I was headed into work this am and noticed a light on in the far left guage. It was yellow and looked like a car with a padlock. I got out and checked/shut all doors and trunk thinking it might be a door/trunk adjar indicator, but it wasn't. Can you tell me what it is and what action may be required by me? Thanks in advance. (Tried to find online user guide first, but no luck)

This is for your Theft Deterrent System. If this light is on while driving, it may indicate a problem with arming or disarming the theft deterrent system. I fit continues to come on while driving you should take it to the dealer and have them check it out. Check your owners manual for more info.