This artifact can be found when Joel is confronted by a man named Malick while passing through a bus in the slums, in which Tess orders him to sit down. Upon leaving the bus, walk straight until you come up behind a man and a woman leaning against a fence discussing how another man hoards stuff in a nearby warehouse. The poster is to the left of them on an olive-green container, which has another red container on top of it.
Note: All punctuation and capitalization are typed up as it appears in the game, when you choose to read it in text-form.
FOR FIREFLY AFFILIATION
There is another copy of the same artifact available to find in the Left Behind. The only noticeable difference is that the word "WANTED" has been replaced with "HERO".