I was checking my filter today and noticed it seems to be burnt? Has less than 10000 miles on it and I got it in July...
I had my last air filter for 20000+ miles and it looked nothing like this...










Any idea what's causing this?
Could it be the worn out foam seal?
Where could I get a replacement foam seal?

 

It's just dirt. Being at the edge and corner I would suspect a slight leak of the box seal focused the dirt at those points.

 

Is just dirt and a little oil from the breather you might want to check/clean/replace the PCV valve. Just looked again disregard the oil and PCV its just your shadow taking the picture.

 

You are missing the foam on your airbox cover.... https://www.f150forum.com/f4/bog-dow...solved-166431/