Most cloud breaches? Not sophisticated attacks. Not genius hackers. Just someone who left an S3 bucket public or gave an IAM role way too many permissions. It’s painfully common. The frustrating part is that AWS actually gives you tools to prevent this stuff. Most people just don’t turn them on. Worth looking into if you haven’t already. I’m not saying you need all of them on day one, but they’re solid starting points.

1. GuardDuty

GuardDuty watches your environment 24/7 and tells you when something weird happens. It pulls from CloudTrail, VPC Flow Logs, and DNS logs to build a picture of normal activity, then alerts you when things deviate. What kind of weird? EC2 instances suddenly mining crypto. Login attempts from countries where you have zero employees. IAM keys being used from IP addresses nobody recognizes. That sort of thing. Is it perfect? No. You’ll get some noise. But I’d rather deal with a few false positives than find out three months later that someone was camped out in my environment. Turn it on through AWS Organizations so every account gets covered. And pipe the findings into whatever SIEM you’re using. Alerts sitting in the AWS console don’t help anyone.

2. Security Hub

The more security tools you run, the more places you have to check. It gets scattered fast, which is exactly the problem Security Hub solves. Security Hub pulls everything into one place. It continuously scans your environment against security best practices and shows you exactly where you’re falling short. The part I actually like is how it ranks findings by severity. Makes it easier to focus on what matters instead of getting lost in a pile of alerts. Hook it up to Systems Manager Automation and you can auto-fix the obvious stuff too.

3. IAM Access Analyzer

Permissions in AWS get messy fast. Someone needs cross-account access for a project, you grant it, project ends, nobody removes it. Multiply that by a hundred times across a few years and you’ve got a disaster waiting to happen. Access Analyzer scans your resource policies and shows you everywhere you’ve granted external access. That S3 bucket accessible to some random AWS account you don’t recognize? It’ll find it. IAM roles that can be assumed by accounts outside your org? Found. The policy generation feature is actually pretty solid too. Instead of guessing what permissions a role needs (and usually guessing too high), you can generate policies based on what the role actually does. Takes like 90 days of activity data but worth the wait.

4. CloudTrail

If there’s one tool on this list I’d never skip, it’s CloudTrail. CloudTrail logs every API call in your account. Every. Single. One. When something goes wrong and you need to figure out what happened, this is how you do it. Without logs, you’re just guessing. Someone deleted a critical resource at 2 AM? CloudTrail tells you who. Suspicious activity from an IP you don’t recognize? CloudTrail has the receipts. Auditor asking for evidence of access controls? Point them at CloudTrail.

5. Config

Here’s the thing about misconfigurations: they creep in slowly. Someone opens up a security group "temporarily" for testing. An engineer spins up an unencrypted database because they’re in a hurry. Six months later you’ve got thirty things that violate your security policies and nobody noticed. Config tracks your resource configurations over time and checks them against rules you define. Unencrypted RDS instance? Flagged. Security group with 0.0.0.0/0 on port 22? Flagged. S3 bucket without versioning? You get the idea. Set up the managed rules AWS provides. They cover most of the obvious stuff. Then hook it up to auto-remediation so violations get fixed automatically. Otherwise you’re just generating alerts that pile up in a queue nobody looks at.

Why All Five?

These tools overlap on purpose. GuardDuty catches active threats. Security Hub gives you the big picture. Access Analyzer keeps permissions from spiraling out of control. CloudTrail gives you the forensic trail when things go sideways. Config stops misconfigurations from piling up. Run all five. Seriously. The cost is minimal compared to what a breach costs. And if you’re scaling your AWS footprint without these basics in place, you’re building on a shaky foundation.