The green from the picture looks.. strange. I'd expect a brand/tattoo, but not a green spot like that.
It should also not be dry and flaky. It has been cured with salt, so that may be what you're seeing.
Some hams will smell weird right out of the packaging. I don't think I've experienced one as bad as you're describing, though, but it could be the mold. I suggest cleaning off the mold and slicing it to see how the fat looks. Yellow fat is rancid and will stink. The fat should be white.
You might see yellow on the outside and white on the inside. In any case, the yellow shouldn't be more than a couple of millimeters wide in a slice. Just to be clear: DON'T EAT THE YELLOW FAT.
--answering your comment on another answer - the "outside" part of the ham will have skin or just fat, but the "inside" part will have exposed meat, and bone. Sometimes that will be covered with plastic or fabric, but you should take that off and clean the ham since it smells.
Also, cut and discard a vertical slice from the exposed side before you get ready to cut slices so you don't have to cut it off the individual slices. You can do the same for the yellow fat, but be careful not to cut all the fat off. A smaller knife makes this easier.