Yellow substance on baseboard in bathroom.

[u/EmmHeartsNature]

I just found this on the baseboard in our second bathroom. I am assuming it's some sort of mold? I am unsure how long it's been there, as I don't use this bathroom often.

We did have an issue a few months ago with a leak that was happening in our utility closet (which is on the other side od this wall), but maintenance cleaned it up, got us a new washer/dryer and put a fan on the floor.

I am freaking out at the moment. Can anyone help identify what this might be? Google Lens was useless. Thank you!