Just to add to the hacking discussion: if Ultron doesn't have any of his Ultron-bots around then there's really no need for him to keep his wireless channels open. If he closes his wireless channels then Cyborg can't hack into him from a distance, he'll need to get up close and plug into him manually... which will probably mean Cyborg gets the crap beaten out of him.
But even if he's able to engage Ultron in a hacking battle, a good chunk of Cyborg's brain and thinking capacity is still human. Ultron's, on the other hand, is predominantly the mind stone with some behavioral patterns from Stark and Banner. I doubt Cyborg can win that match.
JL's best bet is if WW's sword can cut through Ultron, otherwise they lose.