Amazon AWS Certified Security - Specialty SCS-C03 Exam Questions

Answer : B, D, F

AWS incident response best practices emphasizerapid containment, credential revocation, and threat detectionto minimize the blast radius of a compromise. According to the AWS Certified Security -- Specialty Official Study Guide, when unauthorized resources such as an Amazon S3 bucket hosting malware are discovered, immediate action must be taken to stop further misuse of the account and to prevent recurrence.

Rotating or deleting all AWS access keys (Option D)is a critical containment step. If an IAM user has been compromised, any long-term credentials associated with that user must be revoked immediately to prevent continued unauthorized access. AWS guidance explicitly lists access key rotation or deletion as a first-response action for suspected credential compromise.

Deleting unrecognized or unauthorized resources (Option F)directly removes the malicious infrastructure that is being abused. In this case, deleting the unauthorized S3 bucket immediately stops malware distribution and reduces reputational and compliance impact.

Turning on Amazon GuardDuty (Option B)enables continuous threat detection by analyzing CloudTrail events, VPC Flow Logs, and DNS logs. GuardDuty can identify additional malicious activity, compromised credentials, or persistence mechanisms that the attacker may have established. AWS documentation recommends enabling GuardDuty during or immediately after an incident to detect ongoing or future threats.

Option A does not reduce the impact of the current compromise. Option C is overly disruptive and not recommended; credential rotation should be targeted. Option E is unnecessary because there is no indication that EBS-backed compute resources are involved.

AWS incident response guidance clearly prioritizescredential revocation, malicious resource removal, and threat detectionto minimize consequences.

AWS Certified Security -- Specialty Official Study Guide

AWS Incident Response Best Practices

Amazon GuardDuty User Guide

AWS IAM Security Best Practices

Answer : B

AWS Key Management Service (KMS) customer managed keys areregional resources. According to the AWS Certified Security -- Specialty Official Study Guide and KMS documentation, a KMS key created in one AWS Regioncannot be used directly in another Region. When copying an encrypted Amazon Aurora DB snapshot across Regions, the destination Region must have access to a KMS keythat exists in that Region.

Because the original KMS key resides in us-east-1, it cannot be accessed or referenced in us-west-1. The correct and supported approach is tocreate a new customer managed KMS key in us-west-1and specify that key when performing the cross-Region snapshot copy. Amazon RDS automatically decrypts the snapshot using the source Region key and re-encrypts it using the destination Region key during the copy process.

Option A is invalid because KMS keys cannot be stored or transferred through AWS Secrets Manager. Options C and D are incorrect because IAM policies cannot grant cross-Region usage of a KMS key; KMS enforces strict regional boundaries regardless of IAM permissions.

AWS documentation clearly states thatcross-Region encrypted snapshot copies require a KMS key in the destination Region, making this approach mandatory for compliance and encryption continuity.

AWS Certified Security -- Specialty Official Study Guide

AWS Key Management Service Developer Guide

Amazon Aurora Security Documentation

Answer : A, D

In a properly segmented VPC architecture,public subnets route internet-bound traffic to an internet gateway, whileprivate subnets route outbound internet traffic through a NAT gatewaythat resides in a public subnet. According to the AWS Certified Security -- Specialty Official Study Guide and Amazon VPC documentation, private subnets must never have a direct route to an internet gateway.

The issue described indicates that private subnets are incorrectly routing traffic directly to the internet gateway. To remediate this, aNAT gateway must be provisioned in each public subnetto ensure high availability across Availability Zones. This satisfies the requirement that private resources can initiate outbound connections without being directly reachable from the internet.

Next, the route tables associated with theprivate subnets must be updatedso that the default route (0.0.0.0/0) points to the NAT gateway in the same Availability Zone. This ensures proper traffic flow and prevents cross-AZ dependencies.

Option B is incorrect because NAT gateways must reside in public subnets. Option C is unnecessary because local routes to the VPC CIDR range are automatically created. Option E is explicitly insecure, as it would reintroduce direct internet gateway access from private subnets.

AWS documentation consistently identifiesNAT gateways plus correct private subnet routingas the standard design for secure VPC segmentation.

AWS Certified Security -- Specialty Official Study Guide

Amazon VPC Route Table Documentation

AWS Well-Architected Framework -- Security Pillar

Answer : A

Amazon CloudWatch Logs provides a centralized, scalable service for collecting and storing logs from Amazon EC2 instances, regardless of whether the instances are On-Demand or Spot Instances. According to the AWS Certified Security -- Specialty Official Study Guide, CloudWatch Logs is therecommended service for centralized log aggregation and near-real-time analysisof application and system logs.

By configuring all EC2 instances to send logs to asingle CloudWatch Logs log group, the security engineer ensures that logs from all instances are available in one centralized location. Access to the log group can be restricted by using IAM policies, ensuring that only authorized users can view and analyze the logs.

CloudWatch Logs Insights provides apowerful query language with SQL-like syntax, enabling users to search, filter, aggregate, and analyze log data efficiently. This directly satisfies the requirement for SQL-style queries to identify event patterns and perform root cause analysis without requiring data movement or additional services.

Option B is incorrect because CloudWatch Logs Insights cannot query log files stored in Amazon S3. Option C is inefficient and operationally complex, as Athena cannot directly query CloudWatch Logs log groups. Option D is invalid because Amazon Detective is designed for security investigations using GuardDuty findings, not for general application log analysis.

AWS documentation explicitly states thatCloudWatch Logs combined with CloudWatch Logs Insightsis the most efficient and secure approach for centralized log analysis in EC2-based architectures.

AWS Certified Security -- Specialty Official Study Guide

Amazon CloudWatch Logs Documentation

CloudWatch Logs Insights Query Guide

Answer : C

Amazon Inspector provides native CI/CD integration capabilities that allow security checks to occur before container images are pushed to Amazon ECR. According to AWS Certified Security -- Specialty documentation, Inspector does not block image pushes automatically. Instead, prevention must occur inside the CI/CD pipeline itself.

By generating a Software Bill of Materials (SBOM) using the Amazon Inspector SBOM generator and submitting it to Inspector for scanning, the pipeline can detect critical vulnerabilities before the image is uploaded. If vulnerabilities exceed policy thresholds, the pipeline fails, preventing deployment.

Post-push scanning solutions only detect vulnerabilities after exposure. Event-driven blocking does not prevent the initial risk.

AWS best practices require ''shift-left'' security controls to prevent vulnerable artifacts from entering production.

Referenced AWS Specialty Documents:

AWS Certified Security -- Specialty Official Study Guide

Amazon Inspector CI/CD Integration

Answer : C

Amazon GuardDuty generates security findings when it detects suspicious or malicious activity, includingCryptoCurrency:EC2/* findings that indicate an EC2 instance may be involved in unauthorized cryptocurrency mining. According to AWS Certified Security -- Specialty documentation, GuardDuty findings are published as events toAmazon EventBridge(formerly Amazon CloudWatch Events).

Amazon EventBridge is the recommended service for buildingautomated incident response workflows. By creating an EventBridge rule that listens for GuardDuty findings of type CryptoCurrency:EC2/*, the security engineer can automatically invoke a Lambda function to isolate the affected EC2 instance by modifying its security group attachments.

Option A is incorrect because GuardDuty does not directly invoke Lambda functions. Option B and Option D are incorrect because AWS Config tracks configuration compliance and resource changes, not real-time threat detection events. Cryptocurrency findings are security detections, not configuration changes.

AWS documentation explicitly describes this pattern---GuardDuty EventBridge Lambda remediation action---as a best practice for automated threat response and containment.

AWS Certified Security -- Specialty Official Study Guide

Amazon GuardDuty User Guide -- Findings

Amazon EventBridge User Guide

AWS Incident Response Best Practices

Answer : C

Amazon Inspector is the AWS service designed specifically for vulnerability management across compute workloads, including Amazon ECR container images and AWS Lambda functions. According to the AWS Certified Security -- Specialty documentation, Amazon Inspector provides automated vulnerability assessments for container images stored in ECR by performing enhanced image scanning that identifies common vulnerabilities and exposures (CVEs) in operating systems and application dependencies.

Inspector also supports Lambda code scanning to analyze function packages and container-based Lambda images for known software vulnerabilities. Findings include severity ratings and remediation guidance, allowing security teams to identify and prioritize risks efficiently.

Amazon GuardDuty focuses on threat detection using behavioral analysis and does not perform static vulnerability scanning of container images or Lambda code. AWS Security Hub aggregates findings from other services but does not perform scanning itself.

AWS best practices recommend Amazon Inspector for vulnerability detection in container images and serverless workloads.

Referenced AWS Specialty Documents:

AWS Certified Security -- Specialty Official Study Guide

Amazon Inspector for ECR and Lambda

AWS Vulnerability Management Best Practices