Diamond

Yo on my n52 engine (530 2007) I noticed some oil leaking out around the oil pump/filter (big black cover ) I sopped it up and my oil level is normal. I happened to put a quart in the other month when the oil bar was 1 low (wasnt asking me to add but did so) and possibly added too much? What else causes this filter area or pump (not sure what it is) to leak?