Moaron is not specifically a misspelling, eg. 'lol' and 'lulz'. However, people do tend to spell it 'moron'.
Basically, the word moaron can be used in extreme cases, but usually, people just use it to subconciously prove that they're being morons.
"It's two o' clock...the clock's just up there on the wall, moron."
"Lol, look at the moaron who just posted he's underage on the message boards!"