active defense
noun
Cyber defensive measures designed to inflict damage on an attacker, by exploiting vulnerabilities in attack toolkits, distributing disinformation, inflicting malicious code, etc. Enterprises may undertake active defense against threats to themselves. In its more aggressive forms, active defense is a controversial defensive strategy. Contrast cyber vigilantism. Not to be confused with Active Cyber Defense, which involves no operations against non-cooperating networks or systems.