SCS-C02 Infrastructure Security Practice Question

A security engineer needs to audit all changes to AWS resources in an account. Which AWS service should be enabled?

⚠ Common exam trap

Candidates often confuse AWS Config's configuration tracking (which shows what changed) with CloudTrail's API audit trail (which shows who changed it and how), leading them to pick AWS Config when the question explicitly asks for auditing all changes, which requires the API-level logging only CloudTrail provides.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

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AWS CloudTrail

AWS CloudTrail is the correct service because it records API activity and changes to AWS resources as events, providing an audit log of who made what change, when, and from where. This directly meets the requirement to audit all changes, as every AWS API call (e.g., CreateInstance, ModifySecurityGroup) is captured in a CloudTrail event history or delivered to an S3 bucket for long-term analysis.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Amazon Inspector
Why it's wrong here
Amazon Inspector is a vulnerability management service that scans EC2 instances, container images, and Lambda functions for software vulnerabilities and unintended network exposure. It does not generate an audit trail of who modified a resource or which AWS API operation triggered the change, so it cannot answer the security engineer's auditing question.
✓
AWS CloudTrail
Why this is correct
AWS CloudTrail records every AWS API call as an event, capturing the identity of the caller, the source IP address, the request parameters, and the response elements. For an audit of all resource changes, CloudTrail is the authoritative source because nearly every modification to an AWS resource is implemented through a management-plane API call that gets logged.
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AWS Config
Why it's wrong here
AWS Config continuously evaluates and records configuration changes to resources, giving you a timeline of what state each resource was in at various points. However, it records the resulting configuration state, not the underlying API call or the IAM principal who made it, so it lacks the identity and request-level detail needed for a complete change audit.
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Amazon GuardDuty
Why it's wrong here
Amazon GuardDuty is a threat detection service that analyzes VPC flow logs, DNS query logs, and CloudTrail management events to identify suspicious activity such as crypto mining, credential compromise, or malicious IP access. It is designed to alert on malicious behavior, not to provide a complete, ordered audit log of every resource modification, so it would miss legitimate changes and fail the audit requirement.

Quick reference

AWS S3 Storage Class Comparison

Storage Class	Min Duration	Retrieval	Use Case
S3 Standard	None	Immediate	Frequently accessed data
S3 Standard-IA	30 days	Immediate	Infrequent access, rapid retrieval
S3 One Zone-IA	30 days	Immediate	Non-critical infrequent data
S3 Intelligent-Tiering	None	Immediate–hours	Unknown or changing access patterns
S3 Glacier Instant	90 days	Milliseconds	Archive with instant retrieval
S3 Glacier Flexible	90 days	Minutes–hours	Archive, flexible retrieval
S3 Glacier Deep Archive	180 days	Hours	Long-term compliance archive

Go deeper

SCS-C02 Infrastructure Security Practice Question

Why each option matters

Option-by-option breakdown

AWS S3 Storage Class Comparison

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