Hopefully the picture will come through.
Also, on the right side of the picture it is a shadow, the moisture "stains" are the lighter colored marks in the irregular pattern near the base of the wall.
Anyway, my home is 3 years old and this has been an issue every summer.
The builder who is now bankrupt, said that this moisture was just ambient moisture from the home being new. I spent that first summer spraying 70% rubbing alcohol on the moisture and it eventually cleared up and thought it was a done issue.
However the moisture "stains" are back.
So is this from interior moisture or is it migrating through the wall/floor?
FYI we haven't had the dehumidifier running, BUT we do have AC on in the home and the combustion air intake is inside the basement.
Also, I have done the seran wrap tapeed to the floor test with no hints of moisture.
This moisture is only on the perimeter, below the "diaper" insulation on the wall. The staining is ONLY on the floor not on the walls.