This is a good enough leak that it will blow back under the car and cover the trans and frame.
As posted, clean it really well with a degreaser and pressure washer, then run the engine and look at the oil trail.
This is the last model year that Subaru used the single layer steel head gasket that leaks oil after many miles. The repair is replacing the head gaskets with MLS for a 2.5 turbo.
Other things could be the valve cover gasket, crankshaft cover seal, front oil seal(s) or rear crankshaft seal or spacer plates.
I suspect the oil pan is leaking unless someone has removed it and sealed it properly. It is attached to the block with high strength RTV from the factory and I have never seen a leak. It was always from somewhere else.
