Bra Fat????

I am trying to lose weight and want to take up weighlifting. I want to lose those pieces of blubber I affectionately call bra fat. It just spills all over the sides of my bra and I'm just fed up with it. What kind of muscle is that??? And is there any weight training exercises (whether weight machine or dumbbells or resistance band training) that I can do to firm it up? Websites would be greatly appreciated.