If it was obtained, I would fly it in the opposite direction of search groups. I would fly to a remote location with near to none cell/radar coverage. On the other hand, that would be between Malaysia and Australia (my guess). But then you need a pretty solid strip to land it and you need fuel to refuel it. The third question would be, what to do with it then? What to do with the PAX (who may be pretty hungry by now). There are no political hot topics in that area for which a 777 could be used to do something. Getting more bizarre.