Mold Growing On Foundation Wall
Any mold that's growing on your foundation wall should be
removed and treated as soon as possible, to prevent it from spreading
It looks like the roof gutter downspout and drain is causing most of the problem here. Obviously the downspout is leaking and the leaking water is getting the foundation wall wet.
The longer that this continues on, the larger the mold damage and usually home repair bill. Obviously this foundation wall hasn't been repaired as soon as it should have, but there's no time like the present to make the necessary repairs and prevent more damage to the home.
Home Repair Tip: First and foremost, make sure that you fix the problem, before treating the area for mold. You know what the problem is and now it's time to fix it.
You could fix this type of problem a couple of different ways. You could use the recommended aluminum downspout materials and get rid of the plastic connection or you could extend the downspout lower into the ground drain.
Remember that the mold wouldn't be there if the area wasn't moist or damp. After you have fixed the gutter drainage problem, make sure that you treat the foundation wall with some type of mold removing product like chlorine or bleach.