Suspicious Paint Crack of my Corratec X-Force

I always thought that my Corratec is rather weak for agressive trail riding, that's why I didn't send any gaps and big drops with it. Only pure trail riding with roots, stones and cornering with fast speeds. But few days ago I've noticed a crack near a weld of the frame. I don't understand weather it is a paint crack, or a frame crack? What do you thing of this??