The attachments are a little rusted, but in my novice opinion it's original. Given the dirt, it kind of looks like a ground dug piece. Here's my defense version sports badge to compare to:
SA Wehrabzeichen – SA Defencebadge - Type 1
It has a similar style clasp as this one, though a Redo piece.
Others might have more/better info though, so wait for a second opinion if you're looking to buy it. Even if it's original though, I think you could find a nicer example. They're fairly common.
"Only a real risk tests the reality of a belief." - C.S. Lewis
it looks fine to me,ground dug.
I agree, I see nothing wrong with it.