This detection rule identifies the addition of new Network ACL entries in Amazon Web Services (AWS) through the CloudTrail logs. Specifically, it captures events where the `eventSource` is `ec2.amazonaws.com` and the `eventName` corresponds to `CreateNetworkAclEntry`. The addition of such entries may signify that new attack vectors are being opened, potentially increasing the attack surface of the AWS account. Consequently, monitoring these changes is crucial for maintaining the integrity and security of the network configurations. Users are encouraged to review the ACL configurations regularly and correlate these events with other security logs to ensure that the changes made are legitimate and valid for operational purposes.