Amazon Web Services SCS-C03 AWS Certified Security – Specialty Exam Practice Test

AWS KMS keys are regional resources and cannot be used across Regions. According to AWS Certified Security – Specialty documentation, applications that are deployed in multiple Regions should use region-specific customer managed keys while referencing keys by alias instead of key ID.

By creating a new customer managed key in eu-north-1 and assigning it the same alias as the key in eu-west-1, the application code can continue to reference the alias without modification. Each Region resolves the alias to the correct local key, ensuring encryption continues to function correctly.

Option A is invalid because KMS keys are regional. Option B requires application changes. Option D introduces unsupported alias patterns.

AWS best practices recommend alias-based key references for multi-Region deployments.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS KMS Regional Keys and Aliases

AWS KMS Best Practices

AWS incident response best practices emphasize containment with minimal blast radius while preserving business continuity. According to the AWS Certified Security – Specialty Official Study Guide, isolating a compromised resource while allowing the application to continue operating is the recommended initial response.

By creating an Amazon EventBridge rule that reacts to GuardDuty anomalous traffic findings and invokes an AWS Lambda function, the security engineer can automatically remove the affected EC2 instance from the Auto Scaling group and attach a restricted security group. This immediately stops malicious activity while allowing Auto Scaling to replace the instance and keep the application available.

Option A is inappropriate because EC2 instance profiles do not use long-term access keys. Option C applies subnet-wide changes that could disrupt unrelated workloads. Option D provides notification only and does not meet the automated response requirement.

AWS documentation explicitly identifies instance isolation via security groups as a preferred containment technique that preserves application availability and forensic integrity.

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty User Guide

AWS Incident Response Best Practices

AWS Key Management Service (KMS) customer managed keys are regional resources. According to the AWS Certified Security – Specialty Official Study Guide and KMS documentation, a KMS key created in one AWS Region cannot 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 key that 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 to create a new customer managed KMS key in us-west-1 and 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 that cross-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

In a properly segmented VPC architecture, public subnets route internet-bound traffic to an internet gateway, while private subnets route outbound internet traffic through a NAT gateway that 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, a NAT gateway must be provisioned in each public subnet to 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 the private subnets must be updated so 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 identifies NAT gateways plus correct private subnet routing as 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

When Amazon CloudFront is used in front of an Application Load Balancer, CloudFront becomes the immediate source of incoming requests to the ALB. As a result, AWS WAF logs record the CloudFront edge location IP addresses as the client IPs, not the original viewer IP addresses. This behavior is explicitly documented in the AWS Certified Security – Specialty Study Guide and the AWS WAF and CloudFront integration documentation.

To preserve the original client IP address, CloudFront automatically adds the X-Forwarded-For HTTP header, which contains the IP address of the originating client followed by any proxy addresses involved in forwarding the request. AWS WAF logs include this header, making it the authoritative source for identifying true client IP addresses when CloudFront is used.

Option A is incorrect because VPC Flow Logs capture network-level metadata and will only show CloudFront IP addresses, not the original client IPs. Option C is incorrect because disabling connection reuse does not change how client IPs are logged in AWS WAF. Option D is unnecessary and unsupported as a requirement because CloudFront already provides the required information through standard headers.

AWS documentation consistently states that X-Forwarded-For is the correct and supported mechanism for tracing client IPs in CloudFront-protected applications.

AWS Certified Security – Specialty Official Study Guide

AWS WAF Developer Guide – Logging

Amazon CloudFront Developer Guide – Request Headers

AWS WAF rate-based rules are specifically designed to protect applications from traffic floods and distributed attacks that originate from large numbers of IP addresses. According to the AWS Certified Security – Specialty Official Study Guide, rate-based rules automatically track the number of requests coming from individual IP addresses and temporarily block IPs that exceed a defined threshold.

In this scenario, the malicious traffic originates from hundreds of IP addresses across two countries, mixed with legitimate user traffic. A rate-based rule allows the security engineer to limit excessive request rates without fully blocking access from entire geographic regions, ensuring that legitimate users can still access the application.

Option B is incorrect because geographic match rules block all traffic from selected countries, which would deny access to legitimate users and violate the stated requirement. Option C is invalid because security groups do not support geographic filtering. Option D is not scalable, as manually blocking hundreds of IP addresses is operationally inefficient and ineffective against rapidly changing attacker IPs.

AWS documentation emphasizes that rate-based rules are the recommended first-line mitigation for sudden traffic spikes and potential application-layer DDoS attacks when business continuity must be preserved.

AWS Certified Security – Specialty Official Study Guide

AWS WAF Developer Guide – Rate-Based Rules

AWS DDoS Resiliency Best Practices

Password policies are enforced at the identity provider where authentication occurs. According to the AWS Certified Security – Specialty Study Guide, when IAM is federated with an external identity provider such as on-premises Active Directory, IAM does not manage or enforce password policies. Instead, password requirements such as minimum length must be enforced directly in Active Directory Group Policy Objects.

Amazon Cognito user pools maintain their own user directory and authentication logic. Cognito provides configurable password policies, including minimum length, complexity, and expiration. To enforce a minimum password length for application users, the Cognito user pool password policy must be updated.

IAM password policies apply only to IAM users that authenticate directly with IAM and do not affect federated users or Cognito users. SCPs and IAM policies cannot enforce password length requirements.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS IAM Federation and Password Policies

Amazon Cognito User Pool Security Settings

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 CloudTrail is the authoritative source for identity-related activity across an AWS Organization. According to the AWS Certified Security – Specialty Official Study Guide, CloudTrail records all AWS API calls and authentication events, including federated sign-ins that occur through AWS IAM Identity Center with an external SAML identity provider.

When IAM Identity Center is used, successful federated login events are logged in CloudTrail as ConsoleLogin and AssumeRoleWithSAML events. These events are recorded in the organization’s management account when CloudTrail is configured as an organization trail. This allows security teams to centrally search and correlate authentication activity across all member accounts.

Option A is incorrect because CloudWatch Logs do not natively aggregate authentication events across an organization unless custom pipelines are built. Option B is not scalable and does not provide historical, organization-wide visibility. Option C is invalid because AWS does not ingest external IdP logs into EventBridge automatically, and IdP logs do not reflect AWS-side role assumptions.

AWS documentation explicitly states that CloudTrail organization trails provide centralized visibility into user authentication and access activity across all accounts, making this the fastest and most reliable way to identify when a user logged in during a specific time window.

AWS Certified Security – Specialty Official Study Guide

AWS CloudTrail User Guide

AWS IAM Identity Center Documentation

AWS Organizations Best Practices

AWS CloudFormation supports the use of a service role, which allows CloudFormation to assume a dedicated IAM role to create and manage resources on behalf of users. According to the AWS Certified Security – Specialty Study Guide, using a service role is the most secure and consistent way to ensure predictable stack deployments when users have varying permission sets.

By creating a service role with cloudformation.amazonaws.com as the trusted service principal (Option B), CloudFormation—not individual users—assumes responsibility for resource creation. Updating each stack to explicitly use this service role (Option E) ensures that all deployments use the same permission set, eliminating inconsistencies.

Granting the team members permission to pass the service role via iam:PassRole (Option F) is required so that CloudFormation can assume the role during stack operations. This approach adheres to the principle of least privilege and prevents users from gaining direct access to elevated permissions.

Composite principals (Option A) are unnecessary and insecure. Referencing stack ARNs (Option C) does not solve the root cause. While Option D reflects good policy design, it is implicit in creating the service role and is not a required standalone step.

AWS documentation clearly identifies CloudFormation service roles combined with iam:PassRole as best practice for secure, consistent infrastructure deployments.

AWS Certified Security – Specialty Official Study Guide

AWS CloudFormation Service Role Documentation

AWS IAM Best Practices

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

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 the recommended service for centralized log aggregation and near-real-time analysis of application and system logs.

By configuring all EC2 instances to send logs to a single 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 a powerful 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 that CloudWatch Logs combined with CloudWatch Logs Insights is 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

AWS IAM supports identity federation by allowing external identity providers that use OpenID Connect (OIDC) to authenticate and assume IAM roles. According to the AWS Certified Security – Specialty documentation, IAM OIDC identity providers are the recommended approach for enabling third-party systems, such as external CI/CD pipelines or Git-based repositories, to securely obtain temporary AWS credentials without using long-term access keys.

By creating an OIDC identity provider in IAM and configuring the IAM role trust policy to trust the external IdP, the company enables secure, token-based authentication. The trust policy can include conditions that restrict which repositories, branches, or workflows are allowed to assume the role, enforcing least privilege. AWS Security Specialty guidance emphasizes that this method eliminates static credentials and relies on short-lived tokens issued by the OIDC provider.

Option B is incorrect because IAM Roles Anywhere is designed for workloads running outside AWS that use X.509 certificates, not OIDC. Option C is intended for workforce identity federation, not machine-to-machine authentication. Option D is invalid because AWS RAM does not provide identity federation or authentication capabilities.

This solution aligns with AWS best practices for secure, scalable, and low-overhead authentication for external workloads.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS IAM OIDC Identity Providers

AWS IAM Role Trust Policies

Amazon CloudFront includes a native geo restriction (geoblocking) capability that allows content owners to control access to their distributions based on the geographic location of the viewer. The viewer’s country is determined using the IP address from which the request originates. According to the AWS Certified Security – Specialty Official Study Guide and the Amazon CloudFront Developer Guide, geo restriction is specifically designed for scenarios where organizations must comply with regional regulations, licensing requirements, or data sovereignty policies.

From a cost perspective, CloudFront geo restriction is the most cost-effective solution because it is configured directly within the CloudFront distribution and does not require AWS WAF. AWS WAF introduces additional costs for web ACLs, rules, and request processing, which is unnecessary when the requirement is limited strictly to blocking or allowing access based on country.

Option A is incorrect because maintaining IP ranges for entire countries is operationally complex, error-prone, and not scalable. Country-level IP ranges frequently change, making this approach unsuitable and inefficient. Option B, although technically valid, is not the most cost-effective choice because AWS WAF geo match rules incur additional charges and are intended for advanced Layer 7 security controls such as application-layer attacks. Option D is incorrect because geolocation headers provided by CloudFront are informational only and cannot independently enforce access control decisions.

AWS documentation explicitly recommends CloudFront geo restriction when the sole requirement is country-based access control, reserving AWS WAF for advanced security inspection and threat mitigation use cases.

AWS Certified Security – Specialty Official Study Guide

Amazon CloudFront Developer Guide – Geo Restriction

AWS Well-Architected Framework – Security Pillar

AWS Security Best Practices Documentation

Amazon Macie is the AWS service designed to discover and classify sensitive data in S3. Delegated administration enables centralized visibility across an organization. Security Hub aggregates Macie findings for a single-pane-of-glass view.

Inspector does not scan S3 data. Trusted Advisor is not a sensitive data discovery tool.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon Macie Multi-Account Architecture

Amazon GuardDuty provides fully managed threat detection across accounts when configured with delegated administration. EKS and RDS protections enable workload-aware detection with minimal setup.

Other solutions require custom pipelines and higher operational overhead.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty Multi-Account Architecture

Amazon Cognito identity pools are designed to provide temporary AWS credentials for applications by exchanging an authenticated identity token for AWS Security Token Service (STS) credentials. AWS Certified Security – Specialty guidance distinguishes between Cognito user pools (authentication) and identity pools (authorization to AWS resources). A user pool can authenticate a user and issue tokens, but an identity pool is required to obtain AWS credentials that can be used to sign AWS API requests, such as S3 API calls. The correct mechanism is for the application to use AssumeRoleWithWebIdentity through STS (which is the underlying federation method used by identity pools) to receive temporary credentials for an IAM role that grants S3 permissions. GetId alone does not provide credentials; it returns an identity identifier that is used as part of the credential exchange flow. Options C and D are incorrect because user pool tokens are not AWS credentials and cannot directly sign S3 requests. The solution therefore must use identity pools to map users to IAM roles and retrieve temporary credentials, satisfying the requirement for authenticated API calls using short-lived credentials.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon Cognito Identity Pools and STS Federation

AWS STS AssumeRoleWithWebIdentity

AWS CloudTrail organization trails are specifically designed to provide centralized, organization-wide logging with minimal operational effort. According to the AWS Certified Security – Specialty Official Study Guide, an organization trail records all management events for all member accounts and delivers them to a single Amazon S3 bucket.

To ensure that logs cannot be altered or deleted, Amazon S3 Object Lock in compliance mode must be used. Compliance mode enforces write-once-read-many (WORM) protection, meaning no user, including the root user, can delete or modify objects before the retention period expires. This directly satisfies the requirement that no changes or deletions are allowed for 2 years.

The S3 bucket must reside in the dedicated security account to provide isolation and strong security boundaries. Granting write permissions to the organization’s management account (Option A) aligns with AWS best practices, because the management account owns and manages the organization trail and centrally delivers logs on behalf of all member accounts.

Option B increases attack surface by allowing all member accounts to write directly. Option C does not meet immutability requirements because lifecycle policies do not prevent deletion. Option E introduces unnecessary services and operational complexity.

AWS documentation explicitly identifies the combination of CloudTrail organization trails + S3 Object Lock (compliance mode) as the recommended, lowest-overhead solution for long-term, immutable audit log retention.

AWS Certified Security – Specialty Official Study Guide

AWS CloudTrail Organization Trail Documentation

Amazon S3 Object Lock Documentation

AWS Well-Architected Framework – Security Pillar

SSE-S3 uses AWS-managed keys and does not provide customer control. AWS Certified Security – Specialty documentation states that SSE-KMS with customer managed keys allows full control, auditing, and key rotation. The security engineer must first create a customer managed KMS key, then update the bucket to use SSE-KMS. Existing objects must be re-encrypted to ensure compliance.

SSE-C requires the application to manage keys, increasing complexity and risk. AWS managed keys do not meet the requirement for customer-controlled encryption.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Encryption Options

AWS KMS Customer Managed Keys

Amazon S3 Object Lock in compliance mode provides write-once-read-many (WORM) protection, which prevents objects from being modified or deleted for a specified retention period. According to the AWS Certified Security – Specialty Study Guide, compliance mode enforces immutability even for the root user and cannot be overridden.

Enabling S3 Object Lock requires S3 bucket versioning and ensures that once an object is written, it cannot be changed or removed until the retention period expires. This is the strongest protection against data modification and is commonly used for regulatory and legal retention requirements.

Option A can be bypassed by administrators. Option D only protects against deletions, not overwrites. Option C changes encryption but does not prevent modification.

AWS documentation explicitly identifies S3 Object Lock in compliance mode as the correct solution for immutable data storage.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon S3 Object Lock

Amazon S3 Data Protection and Compliance

Amazon GuardDuty is a fully managed, organization-aware threat detection service that continuously analyzes AWS logs such as CloudTrail events, VPC Flow Logs, DNS logs, EKS audit logs, and RDS activity. According to the AWS Certified Security – Specialty Official Study Guide, GuardDuty is designed to operate at scale across AWS Organizations with minimal operational overhead.

By designating a GuardDuty administrator account in the organization’s management account and enabling GuardDuty organization-wide, the company can automatically enable threat detection across hundreds of AWS accounts. Enabling EKS Protection allows GuardDuty to analyze Kubernetes audit logs for suspicious activity, while RDS Protection provides anomaly detection for Amazon Aurora databases.

Options B, C, and D require custom log aggregation, processing, and analytics pipelines, which significantly increase operational effort and maintenance complexity. Amazon Inspector does not analyze logs, Athena-based analysis is manual, and Kinesis plus Lambda requires custom detection logic.

AWS documentation explicitly identifies GuardDuty with AWS Organizations integration as the recommended solution for centralized, automated threat detection across multi-account environments with minimal operational effort.

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty User Guide

GuardDuty Organization Administration Documentation

AWS WAF string match rule statements allow inspection of HTTP headers, including the User-Agent header. According to AWS Certified Security – Specialty guidance, when malicious traffic can be uniquely identified by a consistent request attribute, such as a device-specific user agent, a string match rule provides precise mitigation with minimal false positives.

IP-based blocking is ineffective for globally distributed botnets. Geographic blocking risks denying access to legitimate users. Rate-based rules limit request volume but do not prevent low-and-slow attacks.

By matching the unique IoT device brand in the User-Agent header, the security engineer can block only malicious requests while preserving customer access.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS WAF Rule Statements

AWS DDoS Mitigation Best Practices

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

AWS Config is a fully managed service that provides continuous monitoring and evaluation of AWS resource configurations against desired configuration baselines. According to the AWS Certified Security – Specialty Official Study Guide, AWS Config is the primary service used to track configuration changes, evaluate compliance in near real time, and display compliance states for individual AWS resources.

AWS Config provides managed rules that directly map to the listed Aurora MySQL security requirements, including encryption at rest, public accessibility, deletion protection, and log exports to CloudWatch Logs. These managed rules continuously evaluate resources and mark them as compliant or noncompliant whenever a configuration change occurs.

The AWS Config dashboard enables security engineers to view per-resource and per-rule compliance states at any point in time, satisfying the requirement to display compliance status for each part of the policy.

AWS Audit Manager (Option A) is designed for audit evidence collection and reporting, not continuous monitoring. AWS Security Hub (Option C) aggregates findings from other services but relies on AWS Config for configuration compliance data. Option D introduces unnecessary custom logic and does not provide a native compliance dashboard.

AWS documentation explicitly identifies AWS Config as the authoritative service for continuous compliance monitoring and visibility.

AWS Certified Security – Specialty Official Study Guide

AWS Config Developer Guide

Amazon Aurora Security Best Practices

AWS Well-Architected Framework – Security Pillar

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

Amazon EC2 security groups are stateful, 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 using stateless network controls. Amazon VPC network ACLs (NACLs) are stateless, 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 that all 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

Network ACLs are stateless and 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 to immediately block traffic at the subnet level without restarting instances or modifying their runtime state.

By adding a deny rule with a lower 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 using network ACL deny rules for rapid, targeted containment when 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

AWS KMS provides condition keys that can be used to tightly scope how and where a customer managed key can be used. According to the AWS Certified Security – Specialty Study Guide, the kms:ViaService condition key is specifically designed to restrict key usage to requests that originate from a particular AWS service in a specific Region.

By configuring the key policy to allow KMS cryptographic operations only when kms:ViaService equals s3..amazonaws.com, the security engineer ensures that the key can be used exclusively by Amazon S3. Even if other IAM principals have permissions to use the key, the key cannot be used by other services such as Amazon EC2, Amazon RDS, or AWS Lambda.

Option A is incorrect because AWS services do not assume identities in key policies. Options C and D modify IAM role policies, which do not control how a KMS key is used by AWS services. AWS documentation clearly states that service-level restrictions must be enforced at the KMS key policy level using condition keys.

This approach enforces strong separation of duties and limits blast radius, which aligns with AWS security best practices.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS KMS Key Policy Condition Keys

AWS KMS Best Practices

AWS abuse notifications are delivered as AWS Health events. According to the AWS Certified Security – Specialty Study Guide, Amazon EventBridge integrates natively with AWS Health and can be used to detect specific event types such as AWS_ABUSE_DOS_REPORT in near real time.

By creating an EventBridge rule that filters for the abuse report event type and publishes directly to Amazon SNS, the solution remains fully managed, low latency, and cost effective.

Polling APIs introduces delay and complexity. CloudTrail does not log abuse notifications. EventBridge with AWS Health is the recommended mechanism for reacting to AWS service events.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS Health and EventBridge Integration

AWS Abuse Notification Handling

AWS CloudFormation supports dynamic references to AWS Secrets Manager, which allow sensitive values to be retrieved securely at stack runtime. According to AWS Certified Security – Specialty guidance, dynamic references prevent secrets from being stored in plaintext in templates, stack metadata, or logs.

Using dynamic references ensures that secrets remain encrypted at rest and are accessed only when required. CloudFormation does not support SecureString parameters for Secrets Manager references, and encrypting templates does not prevent exposure during execution.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS CloudFormation Dynamic References

AWS Secrets Manager Best Practices

AWS CloudTrail data event logging is the correct solution because it is specifically designed to capture detailed, structured, and near–real-time API activity for Amazon S3 object-level operations. When S3 data events are enabled, CloudTrail records actions such as GetObject, PutObject, and DeleteObject, along with critical context including the IAM principal, source IP address, event time, request parameters, and response elements. These logs are delivered in JSON format, making them highly structured and suitable for security analysis, SIEM integration, and automated detection workflows.

Amazon S3 server access logging (option A) provides basic request-level information but does not include full IAM identity context and is delivered with a significant delay, which does not meet the near–real-time requirement. AWS Config (option C) focuses on resource configuration changes and compliance evaluation; it does not log object-level access events. Amazon Macie (option D) is a data security service that uses machine learning to discover and classify sensitive data in S3 and generate findings for anomalous access patterns, but it is not a comprehensive access logging solution.

AWS Security Specialty documentation clearly states that CloudTrail data events are the authoritative mechanism for auditing S3 object-level access with identity attribution and precise timestamps, making option B the correct and best-practice answer

AWS KMS enforces a mandatory minimum waiting period of 7 days before a customer managed key can be deleted. According to AWS Certified Security – Specialty incident response guidance, no method exists to immediately delete a KMS key. The fastest possible deletion is achieved by scheduling deletion with the minimum 7-day waiting period.

In this scenario, although deletion was previously scheduled, the key remains enabled and usable. The most authoritative and reliable method to regain control and reissue deletion immediately is to use the AWS account root user, which has implicit permissions to manage KMS keys regardless of compromised IAM principals.

Option B is incorrect because KMS keys are regional resources; multi-Region keys require coordinated deletion but do not shorten the waiting period. Option C is unnecessary because the key policy already allows kms:*. Option D increases the deletion waiting period to 30 days, which violates the requirement to delete the key as quickly as possible.

AWS documentation clearly states that root user access is the ultimate authority for KMS key management and that 7 days is the minimum deletion window, making this the fastest valid option.

AWS Certified Security – Specialty Official Study Guide

AWS Key Management Service Developer Guide

AWS Incident Response Best Practices

AWS CloudTrail is a foundational security service that records API activity and account events. According to the AWS Certified Security – Specialty Official Study Guide, the only way to centrally and reliably prevent CloudTrail from being disabled across multiple AWS accounts is by using AWS Organizations service control policies (SCPs).

SCPs define the maximum available permissions for all accounts in an organization or organizational unit. By creating an SCP with an explicit Deny for the cloudtrail:StopLogging and cloudtrail:DeleteTrail actions and attaching it to the root OU, the security engineer ensures that no principal in any member account—including administrators—can stop or delete CloudTrail trails. Explicit denies in SCPs cannot be overridden by IAM permissions.

Option A is incorrect because log file integrity validation only detects tampering after logs are delivered and does not prevent CloudTrail from being disabled. Option B protects log data at rest but does not prevent trail deletion or logging suspension. Option D removes read-only permissions and does not affect the ability to stop or delete CloudTrail.

AWS documentation explicitly states that SCPs are the recommended mechanism to enforce mandatory security controls such as CloudTrail logging across an organization, making this the correct and most secure solution.

AWS Certified Security – Specialty Official Study Guide

AWS Organizations SCP Documentation

AWS CloudTrail Security Best Practices

Amazon OpenSearch Service is designed for near real-time log ingestion, indexing, and search across large volumes of data. According to the AWS Certified Security – Specialty Study Guide, OpenSearch supports advanced log analytics use cases and integrates with OpenSearch Security Analytics, which provides prebuilt and custom detection rules.

Security Analytics can continuously evaluate incoming logs from multiple AWS services and generate alerts when detection rules are matched. These alerts can be forwarded to Amazon SNS with minimal configuration. OpenSearch also provides powerful search and query capabilities through APIs and dashboards.

Option C supports detection but lacks advanced correlation and scalable search capabilities. Option B is not a log analytics service. Option D is a visualization service and does not support real-time detection.

AWS guidance recommends OpenSearch Service for centralized, near real-time log analysis and alerting.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon OpenSearch Service Security Analytics

AWS Logging and Monitoring Architecture

Amazon GuardDuty findings provide high-level detection of suspicious activity but are not designed for deep investigation on their own. The AWS Certified Security – Specialty documentation explains that Amazon Detective is purpose-built to support rapid investigations by automatically collecting, correlating, and visualizing data from GuardDuty, AWS CloudTrail, and VPC Flow Logs. Detective enables security engineers to analyze API calls, user behavior, and resource interactions in context without making any changes to the environment.

Using read-only credentials ensures that the investigation does not impact the production application. Amazon Detective allows investigators to pivot directly from a GuardDuty finding into a detailed activity graph, showing which IAM user made anomalous calls, what resources were accessed, and how behavior deviated from the baseline. This significantly accelerates incident investigation.

Options A and C involve applying DenyAll policies, which are containment actions and could affect application availability. Option D requires manual analysis and setup and is slower than using Amazon Detective, which is designed for immediate investigative workflows.

AWS incident response guidance recommends using Detective for rapid, non-intrusive analysis after GuardDuty findings.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty and Amazon Detective Integration

AWS Incident Response Investigation Best Practices

EventBridge natively consumes CloudTrail management events and provides near-real-time notifications.

AWS incident response best practices emphasize rapid containment with minimal blast radius. According to the AWS Certified Security – Specialty Official Study Guide, isolating a compromised resource while allowing the application to continue running is the preferred initial response.

By using Amazon EventBridge to detect GuardDuty findings related to anomalous traffic and invoking a Lambda function, the security engineer can automatically remove the affected EC2 instance from the Auto Scaling group and attach a restricted security group. This immediately isolates the instance while allowing Auto Scaling to launch a replacement instance, ensuring application availability.

Option A is invalid because EC2 instance profiles do not use long-term access keys. Option C affects the entire subnet and could disrupt unrelated workloads. Option D provides notification only and does not meet the requirement for automated response.

AWS documentation explicitly recommends instance-level isolation using security groups as a best practice for initial incident containment.

AWS Certified Security – Specialty Official Study Guide

Amazon GuardDuty User Guide

AWS Incident Response Best Practices