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What is GuardDuty, and what does it detect?

AWS · Advanced level

Answer

GuardDuty is managed threat detection using AWS telemetry such as CloudTrail, VPC flow, DNS, and supported workload signals. It detects suspicious behavior like credential misuse, reconnaissance, malicious IP communication, and workload threats.

Technical explanation

GuardDuty findings need routing, ownership, and response automation; detection alone is not incident response.

Multi-account governance should combine preventive controls such as SCPs with detective controls such as Config, GuardDuty, Inspector, Security Hub, CloudTrail, and Access Analyzer.

Central security, logging, and networking accounts reduce blast radius and protect evidence from workload account compromise.

Every control needs an owner, exception process, alert route, and remediation workflow or it becomes shelfware.

Hands-on example

1. Create a multi-account sandbox or use separate dev/security/logging accounts to test the control pattern.

2. Enable the relevant organization-level service or guardrail, then generate a controlled finding or denied action.

3. Route findings to Security Hub, EventBridge, ticketing, SIEM, or an incident channel with ownership metadata.

4. Document the exception process, remediation automation, and evidence required for audit.

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