Avionics question
 

Excuse my ignorance, but a question arising from the PARF "selling F-16s to Egypt" thread.
This is purely technical question, so any politics can be left out of it.

Modern aircraft are, I gather, essentially flown by computer under the guidance of a human pilot.

Can aircraft being sold overseas be equipped with some sort of hidden "bug" that would allow the aircraft to be disabled remotely?

Detailed answers appreciated.
Assume intelligence but ignorance.

Thanks guys.

Yes

No. See: Iranian air force F-14s and F-4s. They may have trouble getting parts for them (legally and above board) but they still fly their American fighters. Employing them effectively is the hard part.

Those are old airplanes.

For current aircraft: yes

Please explain.