AWS Security Checklist 2025: 10 Critical Steps to Secure Your Cloud

Misconfigurations continue to be the leading cause of cloud breaches. This 2025 checklist covers the most critical AWS security controls you should implement—whether you’re running a side project or managing production workloads.

Use it to review your setup, catch vulnerabilities early, and build security in by default.

1. Secure the Root Account

• Enable MFA (preferably a hardware key like YubiKey or FIDO2)
• Delete root access keys if any exist
• Use an IAM user or IAM Identity Center for daily admin tasks

2. Block Public S3 Access

• Enable Block Public Access at the account level
• Verify bucket-level settings for sensitive workloads
• Monitor via AWS Config rules or Access Analyzer

AWS now enables these protections by default—but older accounts may still be vulnerable.

3. Apply IAM Best Practices

• Use IAM Identity Center (SSO) for human access
• Replace long-term credentials with STS temporary credentials
• Enforce MFA using IAM policies

"Condition": {
  "BoolIfExists": { "aws:MultiFactorAuthPresent": "true" }
}

Use tools like IAM Access Analyzer and Policy Simulator to refine access.

To delve deeper into IAM permissions, learn how to analyze and reduce excessive IAM permissions.

4. Enable Logging Everywhere

Set log retention (30–90 days) to avoid unnecessary costs.

5. Enable Threat Detection

• Enable GuardDuty (monitors DNS, CloudTrail, network activity)
• Enable Security Hub for a centralized security view
• Use AWS Config for continuous assessment and configuration changes logging

Set up SNS alerts for critical and high GuardDuty or Security Hub findings.

6. Harden Network Security

• Audit Security Groups (block 0.0.0.0/0 on SSH/RDP)
• Use SSM Session Manager instead of bastion hosts
• Enable VPC Flow Logs for visibility
• Use private subnets for internal resources
• (Advanced) Consider AWS Network Firewall for deeper inspection

7. Monitor Cloud Costs

• Create AWS Budgets with thresholds for cost spikes
• Enable Anomaly Detection for new service usage or region activity

This helps catch signs of misconfigured resources or potential compromise.

8. Automate Security and Compliance

• Use Control Tower for multi-account environments
• Define custom AWS Config rules with Lambda
• Consider using AWS Config automatic remediation for certain non-compliant changes
• Send weekly Security Hub summaries to email or Slack

Automation helps maintain standards even as your environment grows.

9. Perform Monthly Checks

• Run IAM Credential Reports (or better yet, automate it to detect unused credentials)
• Review Trusted Advisor free security checks
• Track Security Hub Score and set improvement targets

Use these reports to catch drift and stale resources early.

10. Stay Current and Keep Improving

• Review this checklist quarterly
• Subscribe to AWS Security blog updates
• Consider running threat detection simulations using GuardDuty Malware Protection
• Implement Incident Response playbooks to follow in case of incident

Want to go deeper on IAM strategy?
Check out Why You Should Stop Using IAM Users in AWS — a full guide on modern access control in 2025.

Final Thoughts

Security isn’t just about avoiding breaches—it’s about building systems that are resilient by design.

Whether you’re new to AWS or an experienced engineer, this checklist gives you a clear baseline to protect your environment from common mistakes.

Start with the basics. Stay consistent. Keep leveling up. 🔐