what will cause a small oil leak at the oil filter adapter

What is your question?

This adapter mounts to the block and extends off at a right angle to the normal oil filter location. Theres a small leak(drip) where the adapter mounts to the block. how does this adapter mount to the block? I'm assuming an oil ring leak between the block and adapter, but I don't see any bolts holding the adapter. There are 2 pipe plugs in the adapter.