Perimeterator is a distributed security auditing tool designed for continuous monitoring of internet-facing AWS services. The tool automatically enumerates public IP addresses associated with various AWS resources including EC2 instances, Elastic Load Balancers (ELB and ELBv2), RDS databases, and Elasticsearch clusters. The system operates through a distributed architecture using AWS SQS queues for asynchronous communication between components. It consists of scanner workers that can be deployed across different networks to simulate external access patterns and provide visibility into services as they appear from the general internet. The enumeration process identifies potentially misconfigured AWS resources that are exposed to the internet, then queues these targets for network service scanning. Scanner workers process items from the work queue to detect open network services on the identified IP addresses. Deployment is facilitated through provided Terraform configurations, allowing for quick setup within AWS environments. The tool supports continuous auditing workflows by periodically reassessing the attack surface of AWS infrastructure.