Artillery was a hack against cavalry. And cavalry and the carriage was a hack against infantry. It is said that Archimedes used mirrors to burn the enemy fleet. Ships with metal plates were a hack at first like putting inside cannons or flamethrowers.
The first repetition gun was a hack. The first gun that could pass the plane propellers was a hack. The detonation fuse(with radar) was a hack. The first radar detection systems of Germans and English were hacks. They came after the sound detection of planes hacks.
The Chinese used kites with children in war in order to see the enemy from above, certainly a hack. Later people used hot air balloons. The first planes were hacks at first, throwing bombs with your hand and photographing the enemy side or damage reports or correction for artillery kilometres away from sight.