I would imagine that there are few places that a 777 could land at in that part of the world that is not an international airport. It should not be difficult to search any place that could handle such a landing in the next month or so.
If this plane is going to be used in a terrorist attack, it will happen in the next week or so.
And if it’s on the ground in hiding, they’ll need to have sufficient fuel to get it back in the air and to its next (final?) destination. It should be easy to track if there are any smallish airports that suddenly have a need for a lot of extra fuel.
We island is one place that can handle it.