Here is the baseline checklist I always keep in mind when setting up AWS security for a new account. These are the essential steps that form the foundation before layering on anything more advanced.

In the second part, I’ll show how these steps look different in practice for a small company (around 50 employees) versus a large enterprise (over 3000 employees).

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🔑 Baseline AWS Security Checklist (Day 1 Setup)

1. Protect the Root Account
   • Enable MFA (preferably hardware).
   • Avoid using root for daily work — create admin roles.
   • Store root credentials in a secure vault.
2. Identity & Access Management (IAM)
   • Create users/roles with least privilege.
   • Use groups for policy assignments.
   • Turn on IAM Access Analyzer.
   • Rotate credentials regularly.
3. CloudTrail
   • Enable a multi-region trail.
   • Store logs in S3 with encryption and validation.
   • Stream to CloudWatch Logs if real-time alerts are needed.
4. AWS Config
   • Enable in all regions.
   • Record all resources.
   • Start with AWS-managed rules (no public S3, root key usage, encryption checks).
5. GuardDuty
   • Enable across all regions.
   • Use Organizations for centralized management if needed.
   • Route findings to EventBridge → SNS/Slack.
6. CloudWatch
   • Enable detailed monitoring for key services.
   • Set alarms for billing, CPU spikes, and unauthorized API calls.
   • Capture service logs (Lambda, API Gateway, VPC Flow Logs).
7. Security Hub
   • Centralize security findings.
   • Enable CIS AWS Foundations Benchmark.
   • Integrate with GuardDuty, Config, Inspector, Macie.
8. Other Essentials
   • Inspector for vulnerability scans (EC2/ECR/Lambda).
   • Macie for sensitive S3 data.
   • Shield Advanced for public apps.
   • AWS Backup for centralized backup policies.

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🏢 Small Company (~50 Employees)

For a small company, the focus is on simplicity and cost control. Usually, there isn’t a dedicated SecOps team, so DevOps or IT wears the security hat.

1. Root & IAM → Root MFA with one or two admin roles. AWS SSO for convenience.
2. CloudTrail → Single multi-region trail to S3, retained for audits.
3. Config → Only critical rules: public S3, root key usage, unencrypted volumes.
4. GuardDuty → Enabled everywhere, alerts forwarded to Slack or email.
5. CloudWatch → A few alarms: billing, CPU spikes, IAM unauthorized calls.
6. Security Hub → Optional, CIS checks if turned on.
7. Other → Inspector if EC2 is used, Macie if customer PII is stored. Shield Advanced not needed unless there’s a public-facing app.
8. Process → Alerts automated to Slack/email. One person acts as “security champion.”

💡 The mindset here is lean and practical: don’t overspend, but don’t leave big gaps either.

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🏙 Large Enterprise (3000+ Employees)

At enterprise scale, compliance and centralization take over. Security becomes a full-time function with teams and tooling.

1. Root & IAM → Hardware MFA for root. Multi-account setup via AWS Organizations. SCPs to enforce policies. SSO integrated with AD/Okta.
2. CloudTrail → Org-wide trail centralized in a Logging account, encrypted with KMS, logs streamed to SIEM.
3. Config → Org-wide enablement with aggregator. Dozens or hundreds of rules, mapped to frameworks (CIS, PCI, HIPAA). Automated remediation through SSM.
4. GuardDuty → Org-wide deployment. Findings routed to ticketing systems like ServiceNow or Jira, escalated via SOAR.
5. CloudWatch → Central dashboards and alarms with automated playbooks (stop untagged EC2, quarantine compromised instances). Long-term retention of Flow Logs.
6. Security Hub → Org-level aggregation, multiple standards enabled. Findings ingested by SIEM/SOAR.
7. Other → Inspector scans org-wide. Macie enabled for S3. Shield Advanced mandatory for internet-facing workloads. Incident response runbooks automated via Lambda/SSM.
8. Process → 24/7 SecOps team, formal incident response drills, compliance audits, and automated patch management.

💡 The mindset here is scale and resilience: automation, continuous monitoring, and governance across dozens or hundreds of accounts.

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⚖️ Final Thoughts

The checklist is the same across the board — what changes is depth and process maturity.

• In a small company, AWS security is about covering the basics without breaking the budget.
• In a large enterprise, the same tools are deployed with scale, compliance, and automation in mind.

The difference isn’t just tooling, it’s how much people and process are in place to make AWS security effective.

Created By Yao Zhang Using ChatGPT.