From the evidence collected in this thread, I must conclude that Malifaux means "Wrong Apple." :-)
So the next time someone directs this colloquialism at you: "So, how ya like them apples!"
You may simply reply: "MALIFAUX!"
It also confirms that the Neverborn are French, or at least Francophiles (having 1/4 of my lineage from there, I am cool with that).
Or...it is simply some folks trying to give something a cool, dark, old-sounding name.
Its like Mordheim could be translated as "murder home" plus it just sounds cool.