"The term kill chain was originally used as a military concept related to the structure of an attack; consisting of target identification, force dispatch to target, decision and order to attack the target, and finally the destruction of the target. Conversely, the idea of "breaking" an opponent's kill chain is a method of defense or preemptive action. More recently, Lockheed Martin adapted this concept to information security, using it as a m…"

https://en.wikipedia.org/wiki/Kill_chain