Chances are the Black field is an image or text box that has been assigned a color (In this case black) in whatever layout program the artist used (Quark, pagemaker, Indesign, or whatever) before it got converted into a PDF. The 'page count' is very probably another text box placed on top of that black box, with its background assigned no color - making it transparent - and the text made white. Making it look like white text on black 'line' or box. If the designer was efficient he would have made a single text box assigned a black background with white text. (But that can be difficult to place the text 'just right' for a design.)
I'm not sure what the artist did, but the result is the same. Thoes are elements set in the layout program and pretty much unchangable once converted to PDF.
UNLESS of course you have the full version of Adobe Acrobat. There is a tool that will crop a page. so you could crop out the bottom half inch or so. I'm not sure if the free version of Acrobat reader has this function or not, or if there is anything I am missing.
Well I rambled, and guessed, and I could very well be wrong.
But I would guess you are out of luck.