Free Amazon Web Services SCS-C03 Practice Exam with Questions & Answers | Set: 2

AWS Secrets Manager is a regional service that is accessed through private AWS endpoints. In a VPC without internet access, AWS recommends using AWS PrivateLink through interface VPC endpoints to enable secure, private connectivity to supported AWS services. According to AWS Certified Security – Specialty documentation, interface VPC endpoints allow resources within a VPC to communicate with AWS services without traversing the public internet, NAT devices, or internet gateways.

An interface VPC endpoint for Secrets Manager creates elastic network interfaces (ENIs) within the VPC subnets and assigns private IP addresses that route traffic directly to the Secrets Manager service. Because the VPC has private DNS enabled, the standard Secrets Manager DNS hostname resolves to the private IP addresses of the interface endpoint, allowing the Lambda rotation function to communicate securely and transparently.

Option A introduces unnecessary complexity and expands the attack surface by allowing outbound internet access. Option B is incorrect because gateway VPC endpoints are supported only for Amazon S3 and Amazon DynamoDB. Option D violates the security requirement by exposing the VPC to the internet.

AWS security best practices explicitly recommend interface VPC endpoints as the most secure connectivity method for private VPC workloads accessing AWS managed services.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Secrets Manager Security Architecture

AWS PrivateLink and Interface VPC Endpoints Documentation

Network ACLs arestateless, so you must allow both the outbound request and the inboundreturn traffic. For outbound TLS to an internet service on TCP443, you need an outbound allow rule permitting destination port 443. The return traffic from the internet service will come back to the instance’sephemeral port(typically in the range 1024–65535) on the inbound path. Therefore, you must allow inbound TCP traffic on the ephemeral port range to support established outbound connections.

At the same time, the requirement is todeny inbound MySQL (TCP 3306). Because NACLs process rules in order (lowest rule number first), placing an explicit deny for port 3306 as a low-numbered inbound rule ensures that traffic destined for MySQL is blocked even if there are broader allow rules later.

Option B does exactly this: it denies inbound TCP 3306 first, then allows inbound ephemeral ports for return traffic, and allows outbound TCP 443. Option A/D incorrectly allow inbound 443 (not needed for outbound-only TLS) and fail to explicitly allow ephemeral return traffic correctly. Option C allows ephemeral inbound first, and then denies 3306 later; while 3306 is not in the ephemeral range, B is the clean, canonical ordering and matches the intended stateless-return-traffic pattern most directly.

The immediate containment step for exposed access keys is todisable (deactivate) the compromised IAM access key(Option B). This prevents any further use of the leaked credentials, which is essential once secrets are publicly exposed. Creating a new key (Option D) may be part of recovery later, but it does not stop abuse of the already exposed key unless the exposed key is first deactivated.

To determine whether the credentials were used, you need evidence of access activity. Among the provided options, the best fit is generating and reviewing theIAM credential report(Option E). The report includes metadata such as access key status and “last used” style details that help triage whether the user’s credentials have been exercised recently. While deeper investigation would typically rely on CloudTrail “AccessKeyId” searches, the credential report is a quick AWS-native step aligned to the answer choices.

Option A is not correct: IAM Access Analyzer helps identify external access paths to resources and validate policies; it does not provide a definitive history of what a specific access key did. Option C is not a GuardDuty capability—GuardDuty generates findings; it does not “block” a specific access key. Therefore, deactivating the key and using credential reporting to assess recent usage best matches the requirements.

Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

CloudFormation StackSets with service-managed permissions is the correct centralized deployment mechanism for deploying the same CloudFormation template across accounts in AWS Organizations. AWS allows a member account to be registered as a delegated CloudFormation administrator, which can then create and manage StackSets for the organization without using the management account for deployment. This matches the restriction that the Organizations management account cannot be used. Manually assuming roles in every account is operationally heavier and not centralized at the CloudFormation service level. Service Catalog would require provisioning in each account. CodePipeline in every account creates unnecessary distributed pipeline management. StackSets is specifically designed to create, update, and delete stacks across multiple accounts and Regions from one administrative point.

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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

AWS Config is purpose-built torecord resource configuration stateand track how that state changes over time. When multiple updates occur close together, AWS Config captures configuration items that represent the resource’scurrent recorded configuration, which is exactly what a compliance engineer needs to evaluate the final (cumulative) state after a burst of changes. AWS Config also integrates directly with compliance evaluation throughConfig rules, which can continuously assess whether the latest configuration meets required standards. This is the most operationally efficient approach because it avoids building custom log filtering, state reconstruction, or timing logic.

CloudTrail and CloudWatch-based approaches (Options A and C) captureAPI events, not authoritative “current configuration state.” Reconstructing the final configuration from a series of API calls can be error-prone, especially when changes are made by different services, via consoles, or through chained automation. CloudTrail is excellent for “who did what and when,” but AWS Config is the service that maintains thelatest configuration snapshotsuitable for compliance posture evaluation.

AWS Cloud Map (Option D) is for service discovery and naming, not compliance configuration history. Therefore, AWS Config is the correct and most efficient solution.

Comprehensive and Detailed 100to 150 words of Explanation From AWS Certified Security – Specialty topics:

Parameter Store uses AWS KMS to encrypt SecureString parameter values when they are created or changed. When a customer managed key is used, the caller needs explicit KMS permissions, including kms:Encrypt for creating or updating SecureString values. If the application lacks that permission, the update fails. A disabled KMS key also causes failures because AWS KMS cannot perform cryptographic operations with a disabled key. A customer managed key can encrypt many SecureString parameters; existing use by another parameter is not a problem. Standard tier SecureString parameters can use customer managed keys. Using an alias instead of a key ID is also supported, so the alias is not the cause.

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The findingInstanceCredentialExfiltrationindicates that credentials available to the EC2 instance (from the instance profile / IMDS) were likely stolen and then used from an unusual location. The fastest way todeny the malicious actor immediatelyis to invalidate the stolen, currently usable credentials. Because these aretemporary credentialsissued to the instance profile role, the correct first containment action is torevoke active sessionsfor that role so the stolen session credentials stop working. This directly blocks continued API use while you continue investigation and remediation.

Changing security groups (Option A) affects inbound network access to the website but does not stop an attacker from using stolen API credentials against AWS APIs. Installing agents and running assessments (Options B and C) are investigative steps that take time and do not immediately cut off the attacker’s current access. After revoking sessions, best practice incident response typically continues with additional containment and eradication steps such as rotating credentials, reviewing CloudTrail for actions taken, checking for persistence (new IAM users/keys, modified policies), patching the instance, and restricting IMDS (for example, enforcing IMDSv2) to reduce risk of further credential theft.

GuardDuty’s DNS-related detections depend on GuardDuty being able to observeDNS query behaviorthrough AWS-provided DNS resolution paths in the VPC. If a VPC is configured to use acustom DNS resolvervia DHCP options (for example, an OpenDNS resolver) instead of the AmazonProvidedDNS resolver, DNS queries may bypass the visibility path GuardDuty relies on for DNS analysis and pattern detection. In that case, the test traffic (queries to example.com) might not be evaluated by GuardDuty’s DNS finding logic, so no DNS finding is generated—and therefore nothing is forwarded into Security Hub.

Option A is incorrect because VPC flow logs are not a prerequisite for GuardDuty to produce DNS findings; GuardDuty uses native telemetry sources and does not require customer-managed flow logs to be enabled. Option D is irrelevant because the company operates in a single Region, and cross-Region aggregation would not be required for the delegated administrator to see findings from the same Region. Option C is less likely given the setup explicitly states GuardDuty and Security Hub are automatically enabled across accounts; also, even if enabled, the specific lack of a DNS finding points to DNS visibility/configuration rather than a downstream integration toggle.

AWS Config requires permissions at two levels to deliver configuration data: the AWS Config service role and the S3 bucket policy. The AWS Certified Security – Specialty Study Guide states that the S3 bucket policy must explicitly allow the config.amazonaws.com service principal to write objects. Additionally, the IAM role used by AWS Config must allow s3:GetBucketAcl and s3:PutObject.

If either permission is missing, AWS Config cannot deliver snapshots and will log delivery errors in CloudTrail. This dual-permission model ensures least privilege while maintaining secure delivery of compliance data.

Other options reference incorrect principals or irrelevant permissions.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Config Prerequisites