Help identifying this.

I was wondering if some of you could identify what this is. This is in my basement. No wetness to it. No pipes above. Could it possibly of been mold that was cleaned up from the previous owners?

I don’t think it had anything to do with mold. I suspect this is associated with the concrete finishing during construction.

Interesting , Have you got a moisture reading Have you tried to Clean it up if so what did you use and did it Change any thing . How old is the home and was it there when you bought the home
.Any info would be appreciated … Roy

No moisture in this area. I haven’t tried to clean it up. The house is 15 years old and yes it was there when I bought the house. The inspector I had did not comment on it.

Agree. Reminds me of moisture puddling.

thats what i’d think too

It could also be from an oil based product that was spilled causing the concrete to stain.

This would be my guess as well. Concrete can be permanently stained in curing or later since it is permeable.