Forum:KB:Can someone tell me from where this image of Palpatine and Maul was taken from?

Dear Star Wars fans, I really want to know where this image is from? I've been searching for its source for some time now, but can't seem to find it. Is it from a comic book or a novel? And if it is, what's the name of the novel/comic?

http://vignette3.wikia.nocookie.net/starwars/images/f/f7/Maultraining.jpg/revision/latest?cb=20081205060750