SCS-C02 Practice Test 3 — 30 Questions

Question 1

During an incident response, a security engineer needs to preserve the state of an EC2 instance for forensic analysis. The instance is running a production workload that cannot be interrupted. Which of the following actions should the engineer take FIRST to ensure data integrity?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use AWS Systems Manager Run Command to create a memory dump and store it in S3.. During an incident response, preserving volatile data (such as memory contents) is critical before any other action that might alter the system state. AWS Systems Manager Run Command can execute a command (e.g., using `dd` or `LiME`) to capture a memory dump and store it in Amazon S3 without interrupting the production workload. This ensures that forensic artifacts like running processes, network connections, and encryption keys are preserved before any disk-level operations that could overwrite or modify evidence.

Answer

Run the dd command to clone the root volume to another EBS volume.

Answer

Create an AMI from the instance while it is running.

Answer

Take a snapshot of the attached EBS volumes while the instance is running.

Question 2

A security engineer is reviewing a CloudTrail log entry (exhibit). What is the most immediate security concern indicated by this event?

Accepted Answer

A security group rule was added allowing SSH access from any IP address.. The CloudTrail log shows an AuthorizeSecurityGroupIngress API call that added a security group rule with the CIDR 0.0.0.0/0 for port 22 (SSH). This effectively opens SSH access to the entire internet, creating a severe exposure that could allow any attacker to attempt brute-force or credential-stuffing attacks against any EC2 instance associated with that security group. This is the most immediate security concern because it directly introduces a wide-open attack surface.

Answer

The source IP address 203.0.113.5 is from a known malicious IP range.

Answer

The API call was made from the AWS CLI, which may indicate a compromised access key.

Answer

The user JohnDoe did not use multi-factor authentication (MFA) for this API call.

Question 3

A security engineer needs to detect and alert on suspicious API calls made from a compromised EC2 instance. The instance is associated with an IAM role that has permissions to call various AWS APIs. Which AWS service should the engineer use to monitor API calls and trigger alerts?

Accepted Answer

AWS CloudTrail combined with Amazon CloudWatch Events. AWS CloudTrail records all API calls made by or on behalf of the EC2 instance's IAM role. By sending these logs to Amazon CloudWatch Events (now Amazon EventBridge), you can create rules that match specific API actions (e.g., 'ec2:TerminateInstances') and trigger alerts via SNS, Lambda, or other targets. This combination provides real-time monitoring and alerting for suspicious API activity from a compromised instance.

Answer

Amazon GuardDuty

Answer

AWS Config

Answer

VPC Flow Logs

Question 4

A company uses Amazon Detective to investigate security findings. The security team is analyzing a GuardDuty finding of type 'Backdoor:EC2/C&CActivity.B!DNS' for an EC2 instance. The team wants to use Detective to understand the full scope of the incident, including which other resources the instance communicated with and any IAM roles used. However, when the team opens the finding in Detective, they see no network activity data for the instance. The instance is in a VPC with VPC Flow Logs enabled, and Flow Logs are being published to CloudWatch Logs. What should the team do to enable Detective to display the network activity?

Accepted Answer

Ensure that VPC Flow Logs are enabled for the VPC and are being published to Amazon CloudWatch Logs in the same account and Region as Detective.. Amazon Detective ingests VPC Flow Logs from CloudWatch Logs to generate network activity visualizations for EC2 instances. Even though VPC Flow Logs are enabled and published to CloudWatch Logs, Detective requires that the logs are in the same AWS account and Region as the Detective behavior graph. If the logs are in a different account or Region, Detective cannot access them, resulting in no network activity data being displayed for the instance.

Answer

Re-enable the GuardDuty finding in Amazon Detective.

Answer

Enable GuardDuty EKS Audit Logs monitoring.

Answer

Install the Amazon Detective agent on the EC2 instance.

Question 5

A company is using Amazon CloudWatch Logs to store application logs. The security team needs to retain logs for 7 years to comply with regulatory requirements. The logs are accessed infrequently after the first 90 days. What is the MOST cost-effective way to meet these retention and access requirements?

Accepted Answer

Export logs from CloudWatch Logs to an S3 bucket, then use S3 Lifecycle policies to transition logs to S3 Glacier Deep Archive after 90 days.. Exporting logs from CloudWatch Logs to Amazon S3 and using S3 Lifecycle policies to transition them to S3 Glacier Deep Archive after 90 days is the most cost-effective solution. CloudWatch Logs storage costs are higher than S3, and Glacier Deep Archive offers the lowest storage cost for infrequently accessed data that must be retained for 7 years. This approach meets the retention requirement while minimizing costs for logs that are rarely accessed after the initial 90-day period.

Answer

Stream logs to an S3 bucket using Kinesis, then use S3 Lifecycle policies to transition logs to S3 Standard-IA after 90 days.

Answer

Set a retention policy on the CloudWatch Logs log group to 7 years and use CloudWatch Logs Insights for queries.

Answer

Set a retention policy on the CloudWatch Logs log group to 7 years and use CloudWatch Logs lifecycle policies to transition to Amazon S3 Glacier.

Question 6

A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks. The security team wants to inspect all traffic between VPCs using a third-party firewall appliance. Which architecture should be used?

Accepted Answer

Use Transit Gateway with appliance mode and route tables to direct traffic through a firewall appliance in a central VPC.. Transit Gateway with appliance mode enables the firewall appliance in a central VPC to receive traffic from all attached VPCs with symmetric routing, ensuring that both forward and return traffic flows through the same appliance. By configuring route tables to direct inter-VPC traffic to the firewall appliance's elastic network interface (ENI), the security team can inspect all traffic without requiring complex peering or on-premises backhauling.

Answer

Set up AWS Direct Connect and route all traffic through the on-premises firewall.

Answer

Create VPC peering connections between each VPC and the firewall VPC.

Answer

Configure network ACLs in each VPC to block traffic unless it comes from the firewall.

Question 7

During a security review, a security engineer notices that an S3 bucket contains sensitive data but has a bucket policy that allows access from any principal in the account. The engineer needs to identify any unintended cross-account access to this bucket. Which AWS service should be used?

Accepted Answer

AWS IAM Access Analyzer. AWS IAM Access Analyzer helps identify resources that are shared with external principals by analyzing resource-based policies (like S3 bucket policies). In this scenario, the bucket policy allows access from any principal in the account, but IAM Access Analyzer can detect if the policy also grants access to principals outside the AWS account (cross-account access). It generates findings for any policy that allows access from an external entity, making it the correct service to identify unintended cross-account access.

Answer

AWS Config

Answer

AWS Trusted Advisor

Answer

Amazon Macie

Question 8

A security analyst needs to receive an alert when an IAM user attempts to perform an action they are not authorized to perform. Which AWS service can be used to monitor and alert on such authorization failures?

Accepted Answer

AWS CloudTrail with CloudWatch metric filter and alarm. AWS CloudTrail logs all API calls made by IAM users, including authorization failures (e.g., AccessDenied errors). By creating a CloudWatch metric filter on CloudTrail logs for specific error codes like 'AccessDenied' or 'UnauthorizedOperation', you can trigger a CloudWatch alarm to send notifications via SNS. This is the standard AWS approach for monitoring and alerting on unauthorized actions.

Answer

AWS Organizations SCPs

Answer

AWS IAM Access Analyzer

Answer

AWS Config

Question 9

A company uses Amazon S3 to store sensitive data. The security team needs to be alerted when an S3 bucket policy is changed to allow public access. Which combination of services should be used to meet this requirement?

Accepted Answer

AWS Config with AWS Lambda and Amazon Simple Notification Service (SNS). AWS Config can monitor S3 bucket policies for changes that grant public access using a managed rule like 's3-bucket-public-read-prohibited' or a custom Lambda function. When a noncompliant change is detected, AWS Config can invoke an AWS Lambda function to evaluate the policy and publish a notification to Amazon SNS, alerting the security team. This combination provides real-time, policy-driven monitoring and alerting for public access changes.

Answer

AWS CloudTrail and Amazon Simple Notification Service (SNS)

Answer

S3 server access logs and Amazon Athena

Answer

AWS Trusted Advisor and Amazon Simple Notification Service (SNS)

Question 10

An organization uses AWS Organizations and wants to centrally manage Amazon GuardDuty across multiple accounts. What is the correct architecture?

Accepted Answer

Designate a delegated administrator account in Organizations and enable GuardDuty in that account.. AWS Organizations allows you to designate a delegated administrator account for Amazon GuardDuty, which can then centrally manage GuardDuty across all member accounts in the organization. This architecture simplifies enabling GuardDuty and managing findings without needing to configure each account individually, as the delegated administrator can enable GuardDuty for all accounts in the organization from a single point.

Answer

Enable GuardDuty only in the master account; it will automatically monitor all member accounts.

Answer

Use AWS CloudFormation StackSets to deploy GuardDuty in all accounts and regions.

Answer

Enable GuardDuty in each region separately and use cross-region aggregation.

Question 11

During an incident response, a security engineer needs to preserve the state of an EC2 instance for forensic analysis. The instance is running a production workload that cannot be interrupted. Which of the following actions should the engineer take FIRST to ensure data integrity?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Create a snapshot of the root volume.. Creating a snapshot of the root volume is the correct action because it captures a point-in-time, crash-consistent copy of the volume's data without requiring the instance to be stopped or the volume to be detached. This preserves the current state of the running instance for forensic analysis while ensuring the data is not altered by the snapshot process itself, as AWS snapshots are read-only and do not modify the source volume.

Answer

Stop the instance and then create an AMI.

Answer

Use dd if=/dev/xvda over SSH to copy the volume.

Answer

Detach the root volume and attach it to a forensics instance.

Question 12

A company uses Amazon GuardDuty and wants to automatically isolate a compromised EC2 instance by removing it from the security group. Which approach should be used?

Accepted Answer

Create an Amazon EventBridge rule that triggers an AWS Lambda function to remove the instance from the security group.. Amazon GuardDuty publishes findings to Amazon EventBridge, which can be used to trigger an AWS Lambda function. The Lambda function can then call the EC2 API to modify the security group and remove the compromised instance, achieving automated isolation without requiring direct GuardDuty integration with security groups.

Answer

Set up an AWS Config rule to detect the finding and remediate.

Answer

Configure GuardDuty to directly modify the security group.

Answer

Use AWS Systems Manager Automation to automatically modify the security group based on GuardDuty findings.

Question 13

A company is designing a data protection strategy for its Amazon RDS for PostgreSQL database. The database contains sensitive customer data. Compliance requirements mandate that all backups be encrypted at rest and that the encryption keys be rotated annually. Which solution meets these requirements?

Accepted Answer

Enable encryption at rest on the RDS instance using a customer managed KMS key. Enable automatic key rotation in KMS.. Enabling encryption at rest on the RDS instance with a customer managed KMS key gives the company control over the key, and enabling automatic key rotation in KMS satisfies the annual rotation requirement. Customer managed keys support automatic rotation (default 365 days), unlike AWS managed keys, which cannot be rotated on a customer-defined schedule.

Answer

Create an encrypted read replica of the RDS instance and use the replica for backups.

Answer

Use S3 server-side encryption with a customer managed key for automated backups. Configure lifecycle policies to rotate the key.

Answer

Enable encryption at rest on the RDS instance using an AWS managed KMS key. The key will be rotated automatically every year.

Question 14

A security team wants to automatically revoke public access to an S3 bucket when Amazon GuardDuty detects a suspicious API call from a known malicious IP address. Which AWS service should be used to orchestrate this automated response?

Accepted Answer

AWS Systems Manager Automation. AWS Systems Manager Automation is the correct service because it provides a runbook-based orchestration framework that can be triggered by Amazon EventBridge events from GuardDuty findings. It can execute predefined automation documents (e.g., AWS-DisableS3BucketPublicReadWrite) to modify S3 bucket policies and revoke public access without requiring custom code, making it ideal for automated incident response workflows.

Answer

AWS Config

Answer

AWS Lambda

Answer

AWS CloudTrail

Question 15

Which TWO steps should a security engineer take when responding to a confirmed security incident involving a compromised EC2 instance? (Choose 2.)

Accepted Answer

Isolate the instance by changing its security group to deny all traffic. Option C is correct because isolating the compromised EC2 instance by replacing its security group with one that denies all inbound and outbound traffic is the standard containment step that stops lateral movement and command-and-control communication while preserving the instance's volatile state for investigation. Option D is correct because taking EBS snapshots of the instance's volumes captures a point-in-time, read-only copy of the disk that can be mounted on a separate forensic workstation for evidence preservation and analysis without altering the original data. Option A is not appropriate as a first response because reimaging destroys volatile evidence and should only occur after containment and forensic capture are complete. Option B is wrong because deleting CloudTrail logs is log tampering that destroys the audit trail needed for the investigation. Option E is wrong because terminating the instance shuts it down and can destroy volatile memory and instance-store data before evidence is collected.

Answer

Reimage the instance from a clean AMI immediately

Answer

Delete all CloudTrail logs related to the instance

Answer

Immediately terminate the instance to stop the attack

Question 16

A security engineer needs to protect an S3 bucket that contains sensitive data. Which two methods should the engineer use?

Accepted Answer

Apply an S3 bucket policy that restricts access to specific IAM users or roles.. Option C is correct because an S3 bucket policy is a resource-based policy attached directly to the bucket that can explicitly allow or deny access based on principals (specific IAM users, roles, or accounts), conditions such as source VPC endpoint or IP range, and actions, making it the primary tool for restricting who can reach sensitive objects. Option D is correct because IAM policies are identity-based policies attached to users, groups, or roles that define which S3 actions (for example s3:GetObject, s3:PutObject) those identities may perform on the bucket and its objects; combined with the bucket policy, they enforce least-privilege access. Option A is not correct because CloudFront is a content-delivery service that can front an S3 bucket for performance or OAC-based access, but it does not by itself protect the bucket's data or restrict direct S3 access. Option B is not correct because VPC Flow Logs capture IP traffic metadata for network interfaces in a VPC and have no relationship to S3 bucket access control. Option E is not correct because S3 object ACLs are legacy access-control lists that grant only coarse read/write permissions to individual objects and are not the recommended mechanism for restricting sensitive bucket data to specific IAM principals.

Answer

Use Amazon CloudFront to serve the content.

Answer

Enable VPC Flow Logs on the bucket.

Answer

Enable S3 object ACLs.

Question 17

A company uses AWS Organizations with multiple accounts. The security team wants to prevent all users in the production account from disabling AWS CloudTrail or modifying its configuration. What is the MOST effective way to achieve this?

Accepted Answer

Create an SCP in AWS Organizations that denies cloudtrail:StopLogging, cloudtrail:DeleteTrail, cloudtrail:UpdateTrail, and similar actions.. Service Control Policies (SCPs) in AWS Organizations provide centralized, preventive control over the maximum permissions for all accounts in an organization or OU. By creating an SCP that denies CloudTrail actions such as StopLogging, DeleteTrail, and UpdateTrail, the security team can ensure that no user or role in the production account can disable or modify CloudTrail, even if they have IAM permissions. This is the most effective and scalable way to enforce this restriction across the account.

Answer

Use IAM policies to deny only cloudtrail:DeleteTrail for all users.

Answer

Enable CloudTrail log file validation and use AWS Config to detect changes.

Answer

Attach an IAM permissions boundary to all IAM roles in the production account that denies CloudTrail modifications.

Question 18

Refer to the exhibit. A security engineer runs this AWS CLI command to investigate root user logins. The output shows a successful ConsoleLogin event. What should the engineer do next to improve security?

Accepted Answer

Enable multi-factor authentication (MFA) for the root user.. Enabling multi-factor authentication (MFA) for the root user adds an extra layer of security, making it much harder for an attacker to compromise the root account even if the password is known. While AWS recommends avoiding routine use of the root user, the root account cannot be deleted; instead, securing it with MFA is a best practice. Options A and B are incorrect because root user cannot be deleted, and disabling the password alone does not prevent root user login via password recovery or other methods. Option C is incorrect because IAM Access Analyzer analyzes resource-based policies for unintended access, not root user activity; it does not generate findings for ConsoleLogin events.

Answer

Delete the root user account.

Answer

Disable the root user password and require all logins via IAM users.

Answer

Enable IAM Access Analyzer to detect and alert on root user activity.

Question 19

A security engineer wants to capture all DNS queries made by EC2 instances to detect potential data exfiltration. Which AWS service should be used to log the DNS requests?

Accepted Answer

Use Route 53 Resolver DNS Firewall with query logging. Route 53 Resolver DNS Firewall with query logging is the correct choice because it is specifically designed to log all DNS queries made by EC2 instances that use the Route 53 Resolver. This service captures the domain names being queried, the source IP, and the response, enabling detection of DNS-based data exfiltration (e.g., DNS tunneling). It integrates directly with the VPC's DNS resolver, ensuring all outbound DNS traffic from EC2 instances is logged without additional agents.

Answer

Use Amazon GuardDuty

Answer

Enable VPC Flow Logs

Answer

Enable AWS CloudTrail

Question 20

A company uses AWS Organizations with multiple accounts. The security team wants to centralize security logs (CloudTrail, VPC Flow Logs, AWS Config) from all accounts into a single S3 bucket for analysis. What is the MOST secure way to set up this centralized logging?

Accepted Answer

Create a dedicated S3 bucket in the security account with a bucket policy that grants write access to the logging services of all accounts and enforces encryption in transit and at rest.. It uses a dedicated S3 bucket in a security account (not the management account) with a bucket policy that explicitly grants write access to the logging services (CloudTrail, VPC Flow Logs, AWS Config) from all accounts, while enforcing encryption in transit (aws:SecureTransport) and at rest (default SSE-S3 or SSE-KMS). This follows the security best practice of isolating logs in a separate account and using resource-based policies to restrict access, preventing accidental deletion or modification by other accounts.

Answer

Create a dedicated S3 bucket in the management account, enable S3 default encryption, and configure service delivery for each account.

Answer

Configure each account to deliver logs to the same S3 bucket used for other data.

Answer

Create an S3 bucket in each account and use S3 replication to copy logs to a central bucket.