mold in basement wall 3

https://theatticmoldremovaltoday.hexaforgey.com/posts/safe-and-effective-attic-mold-removal-a-homeowner-s-guide

We noticed a dark, musty patch spreading along our basement wall near the floor. It turned out to be mold, probably from a small leak we didn't catch. The smell is getting stronger, and I'm worried about what it might be doing to the air in the house.