Amazon Web Services SCS-C03 - AWS Certified Security – Specialty

Amazon WorkSpaces is a fully managed desktop-as-a-service solution designed to minimize infrastructure and operational overhead. According to AWS Certified Security – Specialty documentation, WorkSpaces supports device trust by using client certificates to restrict access to approved devices.

By deploying client certificates only to company-managed devices and enforcing restricted access at the directory level, the organization ensures that only trusted endpoints can authenticate. This approach avoids the cost and complexity of building and maintaining a custom VDI or managing individual EC2 instances.

Option A and B significantly increase management overhead. Option C is incorrect because IAM does not manage WorkSpaces authentication gateway policies or device trust.

AWS best practices highlight Amazon WorkSpaces with certificate-based device trust as the most efficient solution for secure, managed desktops.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon WorkSpaces Security Controls

Amazon WorkSpaces Device Trust

AWS Config provides managed rules that continuously evaluate resource configurations against compliance requirements. The AWS Certified Security – Specialty documentation highlights AWS Config managed rules as the preferred mechanism for enforcing configuration compliance at scale. The managed rule for encrypted RDS storage automatically detects DB instances and clusters that are created without encryption enabled.

By configuring automatic remediation, AWS Config can immediately invoke corrective actions without manual intervention. Integrating remediation with an Amazon SNS topic enables automated email notifications, while an AWS Lambda function can terminate the noncompliant resource. This creates a fully automated detect-alert-remediate workflow.

Option B requires manual remediation, which increases operational effort and delays enforcement. Options C and D rely on Amazon EventBridge, which evaluates events rather than configuration state and does not provide continuous compliance monitoring. AWS Config is explicitly designed for configuration compliance and governance use cases.

This solution aligns with AWS governance best practices by combining continuous monitoring, automated remediation, and centralized alerting with minimal operational overhead.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Config Managed Rules

AWS Config Automatic Remediation

AWS Shield Advanced is the AWS-native managed service specifically designed to provide detection, mitigation, and visibility for Distributed Denial of Service (DDoS) attacks at both the network and application layers. Shield Advanced integrates directly with Amazon CloudWatch by publishing DDoS-related metrics such as DDoSDetected, AttackVolume, and AttackVector, which can be monitored using CloudWatch alarms to trigger alerts in near real time. This makes option D the correct and fully supported solution.

Amazon Macie focuses on discovering and protecting sensitive data (such as PII) in Amazon S3 using machine learning and does not provide DDoS detection capabilities, making option A incorrect. Amazon Inspector is a vulnerability management service that assesses EC2 instances, container images, and Lambda functions for software vulnerabilities and unintended network exposure; it does not detect live DDoS attacks, so option B is incorrect. AWS Firewall Manager is a centralized management service for configuring AWS WAF, Shield Advanced, and security groups across accounts, but it does not emit native DDoS detection metrics for alerting, which eliminates option C.

According to AWS Security Specialty documentation, the recommended best practice for DDoS detection and alerting is to enable AWS Shield Advanced and configure Amazon CloudWatch alarms on Shield metrics, optionally integrating with Amazon SNS for notifications and AWS Incident Manager for response automation.

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

To let the Shield Response Team assist during DDoS events, the account must explicitly authorize SRT access. The associate-drt-log-bucket operation authorizes SRT access to an S3 bucket that contains log data, including third-party source logs. The SRT also needs an IAM role with the AWSShieldDRTAccessPolicy policy and a trust relationship for the Shield DRT service principal so it can inspect relevant protection and logging information during mitigation. Delegated administration and auto-enable can help manage Shield Advanced across accounts, but they do not by themselves share the specific third-party firewall log bucket with SRT. Security Hub CSPM is unrelated to SRT log-bucket access.

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To restrict activity to a single Region in an OU using an SCP, the standard pattern is an explicitDenyfor requests madeoutsidethe allowed Region, while carving out exceptions forglobal servicesthat do not use aws:RequestedRegion in the same way (or that must remain usable regardless of Region). This is done withEffect: Deny, aConditionusing StringNotEquals on aws:RequestedRegion for the allowed Region (here, eu-west-1), andNotActionlisting the global services that should remain available.

This works because SCPs act asguardrails: an explicit Deny in an SCP overrides IAM Allow in member accounts, ensuring the restriction applies consistently to all existing and future accounts placed in the OU. The StringNotEquals condition ensures the deny triggers for any Region other than eu-west-1. The NotAction exception list ensures that the specified global services are not blocked by this deny statement.

Option A is wrong because StringEquals would deny actionsineu-west-1 rather than outside it. Options B and D useAllowstatements, which do not enforce “only this Region” safely in SCPs unless combined with a comprehensive deny strategy; they would not reliably restrict all other services/regions. Therefore, option C is the correct SCP structure.

CloudWatch Logs Insights is a managed, on-demand query capability designed to search and analyze log data stored in CloudWatch Logs without moving the data elsewhere. AWS Certified Security – Specialty documentation highlights Logs Insights as the lowest-effort method for rapid investigations, because it supports filtering, parsing, aggregation, and time-range queries directly over existing log groups. In this scenario, the logs already exist in CloudWatch Logs with sufficient retention. The engineer can write a query that filters for the suspicious IP address, counts occurrences over the last 7 days, and extracts requested URLs using parsing functions. This satisfies both requirements (count and URLs) immediately, without building pipelines or exporting data. Option B adds operational overhead by provisioning and maintaining OpenSearch ingestion and indexing. Options A and D require exporting data and additional services that are not necessary for a one-week forensic query. Therefore, Logs Insights is the most efficient and cost-effective approach.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon CloudWatch Logs Insights Querying and Investigation Workflows

Continuous monitoring requires an always-on compliance service that evaluates resources over time. AWS Config provides managed rules that assess configuration state and compliance continuously. AWS Certified Security – Specialty guidance highlights AWS Config for continuous compliance across accounts and regions when used with AWS Organizations. The ec2-managedinstance-applications-required managed rule evaluates whether specified software is installed on managed instances, leveraging Systems Manager inventory/managed instance status. By enabling AWS Config organization-wide and deploying this managed rule across all accounts, the company can continuously evaluate both existing and newly launched instances for required application presence. This provides a consistent compliance dashboard and history of compliance changes. Option D can provide inventory lists, but it is not a compliance rule engine that flags noncompliance with the same governance reporting and remediation pathways. Options B and C are operational approaches but do not provide continuous compliance state across the organization.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Config Managed Rules for EC2 and SSM Managed Instances

AWS Organizations Integration with AWS Config

To ensure traffic from a VPC to AWS KMS stays on the AWS network and does not use public endpoints, you should use aninterface VPC endpoint (AWS PrivateLink) for KMS. Creating aVPC endpoint for KMS with private DNS enabled(Option C) causes standard KMS DNS names (for example, kms. < region > .amazonaws.com) to resolve to theprivateendpoint IPs inside the VPC, routing requests over the AWS private network rather than through the internet. This is the core networking control that satisfies “no public service endpoints.”

To enforce that only calls that come through the intended VPC endpoint can use the key, add an authorization guardrail in theKMS key policyusing the aws:sourceVpce condition (Option A). This ensures that even if a principal has credentials, KMS will deny usage unless the request is made via the specified VPC endpoint, preventing accidental or malicious use over public paths.

Option B is neither necessary nor sufficient: removing an internet gateway does not prevent all public endpoint use (NAT, other egress paths, or other VPCs could still be involved) and can break workloads. Option D is unrelated to runtime KMS API traffic. Option E is weaker because SourceIp checks can be bypassed via other AWS network paths and does not guarantee PrivateLink usage the way sourceVpce does.

The company uses two different identity systems, and password policy must be enforcedat the system that actually stores and manages the passwords. For users authenticating throughIAM federation with on-premises Active Directory, IAM is not storing the users’ passwords; the password policy is enforced byActive Directory. Therefore, the minimum password length must be configured in theon-premises AD password policyso federated users are subject to the requirement during password creation/changes.

For the cloud application that usesAmazon Cognito user poolsas its user database, Cognitodoesstore and manage user passwords for those users. Cognito user pools include a configurable password policy (minimum length and complexity requirements). Updating the Cognito user pool password policy enforces the required minimum length for the application’s users going forward.

Options D and E are not applicable. Service control policies (SCPs) restrict AWS API actions; they cannot enforce end-user password-length rules inside AD or Cognito. Similarly, IAM policies control authorization to AWS resources and APIs, not password complexity/length requirements across external IdPs or Cognito user databases. Updating IAM password policy (Option A) would apply only toIAM users(local users in AWS), which is not the authentication model described for the federated workforce.

Network ACLs arestatelessand are evaluated in order based on rule number, with lower rule numbers taking precedence. According to AWS Certified Security – Specialty incident response guidance, network ACLs can be used toimmediately block traffic at the subnet levelwithout restarting instances or modifying their runtime state.

By adding a deny rule with alower priority number (10)that explicitly denies TCP traffic on port 22 from the offending IP address (10.0.1.5), the unauthorized SSH session is immediately interrupted. This approach satisfies the requirement to keep the instance running and to preserve memory for forensic analysis.

Option A violates the requirement because restarting the instance clears memory. Option C would disrupt all legitimate SSH access, not just the unauthorized session. Option D would block all internet access and could cause widespread service disruption.

AWS documentation emphasizes usingnetwork ACL deny rules for rapid, targeted containmentwhen immediate interruption is required without altering instance state.

AWS Certified Security – Specialty Official Study Guide

Amazon VPC Network ACL Documentation

AWS Incident Response Best Practices