A company has Windows Amazon EC2 instances in a VPC that are joined to on-premises Active Directory servers for domain services. The security team has enabled Amazon GuardDuty on the AWS account to alert on issues with the instances. During a weekly audit of network traffic, the Security Engineer notices that one of the EC2 instances is attempting to communicate with a known command-and- control server but failing. This alert does not show up in GuardDuty. Why did GuardDuty fail to alert to this behavior?