They might be wall anchors, maybe an inquiry to the previous owner might shed some light...In any case, you should make mention and cite local or IRC code about the stucco below grade. I'm pretty sure there is no exception for IFC walls to this, but you should check the local codes in case.
Even if they allow it, it's not a good idea because it will lead to a weakened system over time.
What did they do at the slab locations at the entry or patios? Do you have any other pictures?

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