Question 1: What distinguishes an unknown threat from a known threat? What types

Question 1: What distinguishes an unknown threat from a known threat? What types of controls address risks from unintentional insider threats? As the IT security specialist, what actions would you take to identify where the risks exist for your organization, both external and internal?
Question 2: As part of your threat hunting proposal, you need to identify the benefits of the program. You have listed opportunities to close attack vectors, reduce the attack surface, and bundle critical assets within additional layers of security controls. What other benefit(s) does threat hunting offer? What would you recommend that your company do first, based on your research to reduce the attack surface and vulnerabilities?
Each question is 250-300 words.