Short for Stupid noobie. First used in a self deprecating manner by one of the then nascent Fannibals (fans of the TV Show, Hannibal) who exploded into fandom.
A super geeky homage to a story arc from the 90's PBS series, Ghost Writer- Stoop Dude was utterly annoying, mucking things up.
"Sorry to be a stup' n00b, but will you please explain to me how to..."
"Gah! I'm sick of all the stup' n00bs needing us to hold their hands through every simple interaction" (or something less n00b-ish)