You also might want to check your Flash Settings on your Computer. If you have installed Flash Viewer, it is possible it is configure to allow this. If you go to a page that is running a Flash Plugin, and Right Click on the Flash Movie, you can check config settings. There are settings for Webcam and Microphone. You can Turn On and Off Access through there.
Check that -

Other than that i agree, that it doesn't seem like it is a backdoor, more like a motion detection or something along that nature