An insider threat is a type of attack that originates from someone who has legitimate access to an organization's network, systems, or data. In this case, the domain user who encrypted the files on the database server is an example of an insider threat, as they abused their access privileges to cause harm to the organization. Insider threats can be motivated by various factors, such as financial gain, revenge, espionage, or sabotage.

A group policy object (GPO) is a mechanism for applying configuration settings to computers and users in an Active Directory domain. By pushing a GPO update, the systems administrator can quickly and uniformly enforce the new password policy across all systems in the domain.
Deploying PowerShell scripts, enabling PAP, and updating EDR profiles are not the most efficient or effective ways to change the password policy within an enterprise environment.

A two-person integrity security control is implemented to minimize the risk of errors or unauthorized actions. This control ensures that at least two individuals are involved in critical operations, which helps to verify the accuracy of the process and prevents unauthorized users from acting alone. It's a security measure commonly used in sensitive operations, like financial transactions or access to critical systems, to ensure accountability and accuracy.