Are you sure that there is no active hidden threat in your network? Netwrix has a freeware that helps you spot behavior-based anomalies.
The new Netwrix Auditor Free Edition automates user activity monitoring and delivers the details straight to your mailbox every single day. It enables you to detect and promptly respond to threatening activities across multiple systems and applications, such as AD, Exchange, file servers, SQL, Windows Server and more. And it will never expire or stop working when you need it.
Are you an IT pro at a company with 250+ employees?