I wouldn't drive the car until you have removed the pins, pads and the trapped anti-squeal spring plate. The latter holds the pins and therefore the pads in place. Can only suggest it was mis-seated when pads were last changed.
If damaged the part you will need to replace is (5) in above diagram, one for each pad pin, and part number MBS1890. I would check pads and pins as well.
I don't think it is one of the springs - it looks more like one of the anti squeal shims that fits to the back of a brake pad.
