The consultant, who has received an OBE for his work in war zones, has changed his computer and his phone since, but does not feel it is safe to link up to operating theatres remotely.
He would not speculate on who had targeted his computer, or dropped the bomb.
Prof Alan Woodward, from the Surrey Centre for Cyber Security, said Mr Nott’s computer or phone could have been hacked during the operation, but it would have been far easier to gain access at a later date to find out who he had been talking to.
It is a method that has been used by governments and law enforcement agencies for a number of years, he said, adding: “It is a fairly classic way of getting information. You don’t need to do it at the time, you can break in at your leisure.”
There have long been fears over the security of online video messaging forums such as Skype, which has been hit by a number of hacks including those that allow accounts to be taken over remotely.