This is an area on the home that is heavily shaded by a large tree and has a down spout that terminates here too. Im thinking that its possible that at some time the water shed from the roof pooled up in this corner before gutters were installed and the owners may have made an attempt to seal up this area due to leaking inside. It may still pool up here but it hard to tell with all the vegetation.
But there was no evidence of any leaking on the interior materials on the other side of the wall.
The area was covered in vines and I almost did not see what was going on here at first. Ive just never encountered anything like this and needed a second opinion from someone who may have seen something similar.
This material is covering the brick and mortar. Its black in color and somewhat brittle since broke some off to check it out.