The square plate that AuSeeker mentioned is to check the chain tensioner. 4 bolts hold it on, it's really easy to take off and replace the gasket there, but I don't think that's the problem since there's oil/grease all over it, not just under it.
Definitely clean it up, but also check your C/V axle on that side to see if the boot is torn. Mine tore and threw grease all over that side of the engine, it looked a lot like how yours looks. If the boot isn't torn it's probably a power steering leak.