This series of characters and letters is "a word" used by youths to fill time and space, a time waster. For example: "Hey, did you know Jake ;alskdjfed his whole paper?"
"Nah, he was just wasting time, he just wanted to use up space so the teacher wouldn't notice he didn't do anything."
"Wow, that was a good idea, I think I'll ;alskdjf my next paper in class!"
Often seen on social networking sites as: WTF!??/;alskdjf it is nothing more than an expression about wasting time. It's also become a pseudonym in forums and on social networking sites much in the same way Silas Rupert was once used.