Level Up Your AWS Security: A Detailed Prioritized Checklist from the Trenches

When I approach a new organization, there are key areas I focus on when conducting a security audit. AWS security is a complex, ever-evolving landscape, and my goal is to break it down into a structured, actionable process.

Disclaimer: Security is a journey. Adapt this checklist to your needs and keep refining it!

The Easy Wins: Foundational Security

Stage 1: Know Your Territory (Inventory)

• Identify all AWS accounts and their points of contact. Use AWS Organizations for a consolidated view. Maintain a spreadsheet or wiki mapping accounts to business units, owners, and contact info.
• Integrate AWS accounts into AWS Organizations. Centralized management and policy enforcement are key.
• Ensure all account root emails are on distribution lists. Redundancy and shared responsibility are crucial.
• Opt-out of AI services using your data. Review AWS service terms and opt-out if you have privacy concerns.
• Dedicate an AWS account solely for Security operations. Isolation enhances security.
• Create budget alarms. Unexpected costs can be a red flag. Set alerts for budget thresholds.
• Enable Service Control Policies (SCPs) via AWS Organizations. SCPs act as guardrails, preventing policy violations across accounts. Start with basic policies and refine as needed.
• Categorize AWS accounts (production, development, sandbox, etc.). Apply different security policies based on data sensitivity and account purpose.

Stage 2: Back It Up!

• Create regular backups with AWS Backup and S3 replication policies.
• Define backup schedules and retention policies aligned with your RTO and RPO.
• Use cross-region replication for resilience and test your backups regularly.

Stage 3: See and Respond (Visibility and Initial Remediation)

• Enable CloudTrail in all accounts, sending logs to a dedicated S3 bucket in your Security account.
• Activate GuardDuty in all accounts, forwarding findings to your Security account.
• Enable IAM Access Analyzer for policy analysis and resource access visibility.
• Turn off S3 Public Block Access at the account and bucket level.
• Develop an account initialization script and a standardized account creation process.
• Enable VPC Flow Logs for all VPCs to gain insights into network traffic.

Stage 4: Early Warning System (Detection)

• Document your security guidelines.
• Send alerts to a ticketing system (e.g., CloudWatch Events to SNS to email/Slack).
• Enable investigation capabilities for your logs.
• Consider enabling other logging sources (AWS Config, AWS WAF, load balancers, etc.).

Stage 5: Lock Down Access (Secure IAM)

• Implement SSO for centralized identity management.
• Remove all IAM users (except break-glass accounts). Use IAM roles instead.
• Regularly audit and remove unused IAM roles and policies.
• Enforce MFA for all IAM users and roles with console access.
• Plan your account connectivity strategy.
• Implement pre-commit hooks for secret detection.

Stage 6: Shrink the Target (Reduce Attack Surface)

• Avoid publicly accessible EC2 instances and S3 buckets.
• Enforce IMDSv2 on all EC2 instances.

Stage 7: Repeatability and Accountability (Reproducibility and Ownership)

• Apply a comprehensive tagging strategy.

Stage 8: Advanced Detection (Enhance Detection and Least Privilege Refinement)

• Deploy honeytokens.

Stage 9: Secure the Pipes (Secure Network Communications)

• Restrict egress network traffic using security groups and Network ACLs.
• Enforce encryption for all data in transit using TLS/SSL.

Stage 10: Be Prepared (Incident Preparation)

• Limit the blast radius of incidents.
• Practice incident response with simulations and tabletop exercises.
• Establish and maintain a detailed, up-to-date incident response plan.
• Use AWS Trusted Advisor for best practice checks during incidents.

Moderate Measures: Stepping Up Your Game

Stage 1: Inventory - Continuous Compliance

• Conduct regular audits of AWS accounts.

Stage 2: Backups - Resilience and Recovery

• Test recovery procedures regularly.
• Implement cross-region replication for critical backups.
• Use AWS Backup Vault Lock to enforce retention policies.

Stage 3: Visibility and Initial Remediation - Proactive Monitoring

• Centralize logging using AWS CloudWatch Logs.
• Set up AWS Config rules to monitor compliance and configuration drift.

Stage 4: Enhanced Detection - Security Information Management

• Perform regular vulnerability scanning using AWS Inspector.
• Integrate AWS Security Hub to aggregate and prioritize security findings.

Stage 5: Secure IAM Access - Refinement

• Regularly review and tighten IAM access policies.
• Use IAM Access Analyzer to identify overly permissive access.

Stage 6: Reduce Attack Surface - Proactive Defense

• Implement AWS WAF.
• Regularly review and update security group rules.

Stage 7: Reproducibility and Ownership - Automation and Control

• Control AMI and package sourcing.
• Maintain version control for all infrastructure code.

Stage 8: Enhance Detection and Least Privilege Refinement - Real-Time Security

• Implement real-time monitoring.
• Implement automated remediation for common security issues.

Stage 9: Secure Network Communications - Advanced Networking

• Move all non-public network resources into private subnets.
• Use AWS PrivateLink to securely connect services.

Stage 10: Incident Preparation - Practice Makes Perfect

• Conduct tabletop exercises.
• Maintain a forensic data collection plan.

Complex Challenges: Expert Level Security

Stage 1: Visibility and Initial Remediation - Deep Dive

• Create IAM roles in each account that grant read-only access from the Security account.
• Run a one-time scanning tool for tactical remediation of identified vulnerabilities.

Stage 2: Detection - Advanced Threat Hunting

• Implement automated alert correlation.
• Use Amazon Detective for deeper investigation.

Stage 3: Secure IAM Access - Surgical Precision

• Reduce service role privileges to the absolute minimum necessary.

Stage 4: Reduce Attack Surface - Fortress Mode

• Enable AWS Shield Advanced for DDoS protection.
• Implement comprehensive SCPs to enforce security policies.

Stage 5: Reproducibility and Ownership - Infrastructure as Code Excellence

• Use Infrastructure as Code (IaC).
• Implement CI/CD pipelines for infrastructure deployment.
• Conduct regular code reviews with a security focus.

Stage 6: Enhance Detection and Least Privilege Refinement - Continuous Improvement

• Continuously refine IAM policies based on access patterns.
• Conduct regular threat hunting exercises.
• Implement anomaly detection.

Stage 7: Secure Network Communications - Network Segmentation and Control

• Implement VPN or Direct Connect for secure hybrid cloud connectivity.
• Regularly review and audit VPC Peering and Transit Gateway configurations.
• Implement VPC inspection.

Stage 8: Incident Preparation - Ready for Anything

• Establish a dedicated incident response team.
• Use AWS Config rules for automated detection and alerting on compliance violations.