Prowler

Prowler is an open-source cloud security posture management (CSPM) tool that performs automated security assessments of cloud infrastructure. Originally built as an AWS-only auditing script, it has evolved into a comprehensive multi-cloud platform supporting AWS, Azure, Google Cloud, and Kubernetes, with over 500 individual security checks. Licensed under Apache 2.0 and written in Python, Prowler has accumulated over 11,000 GitHub stars and is one of the most widely used open-source tools in the cloud security space.

The tool operates by authenticating to cloud provider APIs using existing credentials (IAM roles, service principals, or service accounts) and systematically evaluating resource configurations against security best practices. Checks cover identity and access management, network security, encryption at rest and in transit, logging and monitoring, data protection, and service-specific hardening. For AWS, Prowler evaluates over 300 checks spanning IAM, S3, EC2, RDS, Lambda, CloudTrail, GuardDuty, and dozens of other services. Azure and GCP check libraries cover equivalent services in each cloud. Kubernetes checks audit RBAC, pod security, network policies, and cluster configuration.

Each finding is mapped to one or more compliance frameworks — CIS Benchmarks, PCI-DSS, HIPAA, SOC2, GDPR, NIST 800-53, FedRAMP, and ENS — making Prowler directly useful for audit preparation and continuous compliance monitoring. Output formats include HTML dashboards, CSV, JSON, and AWS Security Finding Format (ASFF) for direct integration with AWS Security Hub. The commercial Prowler SaaS offering adds a web dashboard, historical trending, multi-account management, and automated remediation workflows for teams that need continuous cloud security posture monitoring at scale.