Any weird sounds coming from your brakes are definitely cause for alarm! The best way to fix contaminated brake pads is to replace them.
While you could attempt to clean your brake pads in warm, soapy water, most brake pads will have to be replaced once contaminated. Oil, grease, and brake fluid can reduce the friction of your brake pad, making it difficult to stop. It’s also why you’re hearing those weird noises!
Because brakes are an integral part of your car and safety, it’s best to take your vehicle to a mechanic. They can determine whether your pads can be safely cleaned or if they need a complete replacement.