Brown streaks down basement walls of potential home

Looking at purchasing a home but noticed these brown streaks all down the walls of the basement, wondering if it looks like a leak, staining from construction, or interior humidity/condensation? Just wondering if it would be a red flag for the home or not. Wooden supports all looked dry to me.

https://preview.redd.it/oyv5os2egqyf1.jpg?width=4284&format=pjpg&auto=webp&s=3fc03cc8b40da00924eaf77221311a1ff02089f1