"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.[1] Conversely, the idea of "breaking" an opponent's kill chain is a method of defense or preemptive action.[2] More recently, Lockheed Martin adapted this concept to information security, using it as a method for modeling intrusions on a computer network.[3] The cyber kill chain model has seen some adoption in the information security community.[4] However, acceptance is not universal, with critics pointing to what they believe are fundamental flaws in the model.[5]"
https://en.wikipedia.org/wiki/Kill_chain
Another link with info
https://www2.deloitte.com/content/dam/Deloitte/sg/Documents/risk/sea-risk-cyber-101-july2017.pdf