Pass the Amazon Web Services AWS Certified Specialty SCS-C03 Questions and answers with ExamsMirror

For encrypted RDS snapshots that must be shared across accounts and still bedecryptablein the target accounts, you should use acustomer managed KMS keyand explicitly grant cross-account use of that key. AWS-managed default keys (Option A/C) generally cannot be shared for cross-account decryption in the same flexible way as customer managed keys, and you cannot “copy” an AWS-managed key to another account. Likewise, you cannot “import” an existing KMS key into another account via Lambda as described in Option B; KMS keys are account-scoped resources and are not copied between accounts like that.

With acustomer managed key (CMK), the key policy (and/or grants) can allow principals in the DR accounts to use the key for the required cryptographic operations (for example, kms:Decrypt, kms:CreateGrant, and relevant describe permissions). Then, when the snapshot is shared and copied/used in the destination account during a DR event, the destination account can decrypt it because it has been granted permission to use the same CMK. This approach is the standard AWS pattern for cross-account encrypted snapshot sharing and meets both encryption and recoverability requirements with strong governance and auditability through CloudTrail.

Amazon GuardDuty provides continuous threat detection for compromised instances by analyzing VPC Flow Logs, DNS logs, and CloudTrail events. According to AWS Certified Security – Specialty guidance, GuardDuty is the fastest service to enable for detecting malware and compromised EC2 instances.

To notify the security team, Amazon SNS provides a native email notification mechanism with minimal setup. Amazon EventBridge integrates directly with GuardDuty findings and can filter based on severity. Creating an EventBridge rule that matches high severity GuardDuty findings and publishes to SNS ensures immediate notification.

Security Hub is not required for this use case and adds additional setup time. Amazon SQS does not support email subscriptions.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty Findings and Severity

Amazon EventBridge Integration with GuardDuty

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

The AWS Config managed rule access-keys-rotated is purpose-built for this requirement. It checks whether active IAM access keys have been rotated within the configured maxAccessKeyAge, with 90 days as the default value. When the rule evaluates an IAM user as NON_COMPLIANT, EventBridge can match the AWS Config compliance change event and publish a notification to Amazon SNS. This uses managed services and avoids custom scripts, credential report parsing, Athena tables, or Lambda code. Trusted Advisor and custom IAM API polling can work, but they introduce more operational effort and more custom logic. The least-effort and most direct solution is AWS Config managed rule plus EventBridge plus SNS.

================

Toenforcerequired tagging and approved values at scale, the strongest guardrail is anSCPbecause SCPs can prevent API calls across accounts/OUs before resources are created or tags are changed. By using the aws:RequestTag/CostCenter condition key and checking that the value is one of the approved values, an SCP candeny Create (and TagResource/UntagResource where supported)* when the request attempts to set a non-approved value. This prevents “bad” CostCenter values from being introduced.

AWS Config (including custom policy rules with CloudFormation Guard) is excellent fordetectingnoncompliance and reporting, but on its own it is not a hard preventative control. Pairing Config rule evaluation with an SCP guardrail gives both visibility and prevention. Option A is the only option that explicitly combines an enforceable preventive control (SCP deny based on aws:RequestTag/CostCenter) with compliance evaluation logic.

Option B cannot “block creation” reliably because EventBridge/Lambda isafter-the-fact; by the time the function runs, the resource is already created. Option C relies on tag policies enforcement semantics; tag policies primarilystandardize and reporttag usage, and the provided SCP in C only checks for null/missing values, not for non-approved values or for preventing later changes. Option D is also reactive and not a guaranteed preventative control.

To achieve true separation of duties, the company needs a design whereS3 access alone is not sufficientto read plaintext data.SSE-KMS with a customer managed KMS keyprovides that separation because successful object reads require both: (1) S3 permissions to read the object and (2) permission to use the KMS key to decrypt it. This enables the operations team to manage bucket and object permissions while the security team independently controls key usage through theKMS key policy(and grants). If either team misconfigures only their part, the data is still protected: an overly permissive bucket policy won’t expose plaintext unless KMS decrypt is also allowed; similarly, KMS permissions alone are not sufficient without S3 read access.

Option B also adds a bucket policy requirement enforcingSSE-KMSso objects are consistently protected with the customer managed key. SSE-S3 options (A and C) do not provide the same separation because S3 manages the keys and decryption is not independently controlled by a separate team via KMS policies. Option D is invalid because SSE-C uses customer-provided keys that are supplied with each request and are not stored/managed in KMS as described. Therefore, SSE-KMS with customer managed keys plus restrictive key policy is the correct solution.

AWS incident response best practices emphasize rapid containment to prevent further data exposure. According to the AWS Certified Security – Specialty Study Guide, the fastest and least disruptive containment method for compromised compute resources is to immediately revoke credentials and permissions rather than modifying data or infrastructure.

Revoking the IAM role’s active sessions prevents the EC2 instance from continuing to access AWS services. Updating the S3 bucket policy to explicitly deny access to the IAM role ensures immediate enforcement, even if temporary credentials remain cached. Removing the IAM role from the instance profile further prevents new credentials from being issued.

Option A and D involve large-scale data movement or re-encryption, which is time-consuming and operationally expensive. Option B relies on network-level controls that do not prevent access through private AWS endpoints.

AWS guidance explicitly recommends credential revocation and policy-based denial as the fastest containment step during active incidents.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Incident Response Best Practices

AWS IAM Role Session Management

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

Amazon EC2 security groups arestateful, meaning that once a connection is established, return traffic is automatically allowed, even if the inbound rule that originally permitted the connection is later removed. According to the AWS Certified Security – Specialty Official Study Guide and Amazon EC2 security documentation,existing connections are not terminated when security group rules change. This explains why the SSH session remains active even after the security group rules were modified, while new traffic such as ICMP ping is blocked.

To immediately and fully isolate an EC2 instance during an incident response scenario, AWS recommends usingstateless network controls. Amazon VPC network ACLs (NACLs) arestateless, which means that every packet is evaluated against the ACL rules regardless of whether the traffic is part of an existing connection. When a deny rule is added,all traffic is immediately blocked, including active sessions.

By creating a network ACL and associating it with the subnet that contains the target instance, and by adding explicit deny rules with the lowest rule numbers for both inbound and outbound traffic, the security engineer ensures thatall network communication to and from the instance is immediately interrupted. This approach satisfies the requirement to isolate the instance while preserving its runtime state and memory for forensic analysis.

Other options fail to meet the requirement because security group modifications do not terminate existing sessions, Systems Manager does not enforce network isolation, and host-level firewall changes require instance-level access and do not provide immediate, network-enforced isolation.

AWS Certified Security – Specialty Official Study Guide

Amazon EC2 Security Groups Documentation

Amazon VPC Network ACL Documentation

AWS Incident Response Best Practices

An RPO of1 hourmeans the company must be able to restore data with at most60 minutes of loss. Option A directly meets this by usingAWS Backupto takehourly backupsof both the compute layer (EC2) and the data layer (S3). AWS Backup provides centralized policy-based scheduling, retention, and (when configured) immutable protections such as Backup Vault Lock to help defend backups from tampering—important in ransomware recovery scenarios. Backing up the S3 buckets hourly also addresses recovery of critical objects such as images and music that users rely on.

In addition, recovery to “normal operations” is not only about data restoration; it also requires rapidly re-creating infrastructure reliably. UsingAWS CloudFormation templatesstored in aversion-controlled Git repositorysupports consistent, repeatable rebuilds of the ALB, EC2 fleet configuration, IAM roles, security groups, and related components. This infrastructure-as-code approach reduces human error under incident pressure and accelerates disaster recovery execution.

Option B fails the RPO because daily backups can lose up to 24 hours of data. Option C focuses on logging/governance rather than backups and does not establish a 1-hour recovery point. Option D also fails the RPO (4-hour snapshots) and is reactive to a specific finding type rather than a comprehensive DR plan for EC2 and S3.

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