What's under the oil pan on a 2002 Outback Sport

Okay, maybe a dumb question, but what's "under" the oil pan? I've noticed something leaking from my car and there's some sort of box attached to the oil pan (at least this is what it looks like--it's not where the plug is).

What is this? Oil pump, maybe? Whatever it is, there's oil all over it.

Any chance you can get a picture?