SCS-C02 Practice Exam 3 — 20 Questions

Question 1

A security engineer runs the command shown in the exhibit. What is the outcome?

Accepted Answer

Default encryption is enabled on the bucket using SSE-S3.. The command `aws s3api put-bucket-encryption --bucket my-bucket --server-side-encryption-configuration '{"Rules":[{"ApplyServerSideEncryptionByDefault":{"SSEAlgorithm":"AES256"}}]}'` enables default encryption on the bucket using SSE-S3, because `AES256` is the algorithm identifier for SSE-S3 (Amazon S3-managed keys). The command succeeds and sets the default encryption configuration to use server-side encryption with S3-managed keys, which is the standard SSE-S3 behavior.

Answer

The command fails because AES256 is not a valid algorithm.

Answer

Default encryption is enabled on the bucket using SSE-KMS.

Answer

The command removes default encryption from the bucket.

Question 2

A startup is building a serverless application using AWS Lambda to process user-uploaded images. The images are stored in an S3 bucket with server-side encryption (SSE-S3) enabled. The Lambda function reads the images, performs transformations, and writes the results to a different S3 bucket. The security engineer wants to ensure that data is encrypted at rest and in transit throughout the pipeline. The Lambda function is configured with an IAM role that has permissions to read from the source bucket and write to the destination bucket. Which additional configuration is REQUIRED to ensure end-to-end encryption?

Accepted Answer

No additional configuration is required; Lambda uses HTTPS by default to call S3.. Lambda uses HTTPS by default when calling S3 API operations, ensuring encryption in transit. SSE-S3 provides encryption at rest on S3, so no additional configuration is needed for end-to-end encryption. Option A is incorrect because while a bucket policy can enforce HTTPS, it is not required; Lambda's default HTTPS connection already provides encryption in transit. Option C is incorrect because SSE-S3 does not use KMS; Lambda can read SSE-S3 encrypted objects without additional KMS permissions. Option D is incorrect because VPC endpoints are not required for encryption in transit; Lambda's default HTTPS calls to S3 are already encrypted.

Answer

Add a bucket policy to the source bucket that denies requests not using aws:SecureTransport.

Answer

Grant the Lambda function's IAM role permission to call KMS Decrypt and Encrypt.

Answer

Enable VPC endpoints for S3 and configure Lambda to use them.

Question 3

A security engineer needs to monitor for unauthorized changes to security group rules in an AWS account. Which AWS service can evaluate security group rules against a desired configuration and alert on changes?

Accepted Answer

AWS Config. AWS Config is correct because it provides a managed rule called 'restricted-ssh' or custom rules using AWS Config managed rules or Lambda functions to evaluate security group rules against a desired configuration. When a security group rule is added, removed, or modified, AWS Config detects the configuration change, evaluates it against the defined rules, and can trigger an Amazon SNS notification to alert the security engineer. This makes AWS Config the appropriate service for continuous monitoring and alerting on unauthorized changes to security group rules.

Answer

AWS Security Hub

Answer

Amazon GuardDuty

Answer

AWS CloudTrail

Question 4

A security engineer is designing a multi-tier web application. The application uses an Application Load Balancer (ALB) to distribute traffic to EC2 instances in private subnets. The engineer needs to ensure that the EC2 instances only accept traffic from the ALB and not from any other source. Which security group configuration should the engineer use?

Accepted Answer

Allow inbound HTTP traffic from the ALB's security group on the EC2 instances' security group.. It uses a security group reference to allow inbound HTTP traffic from the ALB's security group. This ensures that only traffic originating from the ALB (which has that security group attached) can reach the EC2 instances, regardless of the ALB's IP addresses or changes in the VPC CIDR. This is the recommended AWS best practice for securing traffic between an ALB and backend instances.

Answer

Allow inbound HTTP traffic from the ALB's public IP address on the EC2 instances' security group.

Answer

Allow inbound HTTP traffic from the VPC CIDR range on the EC2 instances' security group.

Answer

Allow inbound HTTP traffic from 0.0.0.0/0 on the EC2 instances' security group.

Question 5

A company stores data in Amazon S3 and uses AWS KMS with Customer Master Keys (CMKs) for encryption. The security team wants to audit when the CMK is used to decrypt data. Which of the following will provide this information?

Accepted Answer

AWS CloudTrail. AWS CloudTrail logs all KMS Decrypt API calls, which is exactly what is needed to audit CMK decryption. Option A (AWS Config) records configuration changes, not API calls. Option B (Amazon CloudWatch Logs) can store logs but does not generate the KMS decrypt logs itself; CloudTrail generates them. Option D (S3 server access logs) record requests to S3 objects, not the KMS decryption calls that happen when accessing encrypted objects.

Answer

AWS Config

Answer

Amazon CloudWatch Logs

Answer

S3 server access logs

Question 6

A company has enabled Amazon GuardDuty in multiple AWS accounts. The security team wants to centralize GuardDuty findings into a single account for analysis. Which THREE steps are required to achieve this? (Choose THREE.)

Accepted Answer

Invite member accounts to join the GuardDuty master account.. In Amazon GuardDuty, to centralize findings from multiple accounts, you must designate a master account and then invite member accounts to join. The invitation process establishes a trusted relationship where the master account can aggregate and analyze findings from all member accounts. Without this step, the master account cannot receive findings from other accounts.

Answer

Configure CloudWatch Logs cross-account subscription to aggregate findings.

Answer

Create an EventBridge rule to forward findings to the master account.

Question 7

A company has multiple AWS accounts and wants to centrally aggregate VPC Flow Logs from all accounts into a single S3 bucket in the logging account. What is the MOST secure way to configure cross-account delivery?

Accepted Answer

Create VPC Flow Logs in each account, specifying the central S3 bucket ARN as the destination, and configure the bucket policy to allow the flow logs service principal to write.. VPC Flow Logs can be published directly to an S3 bucket in another account by specifying the bucket ARN as the destination. The logging account's bucket policy must grant the `s3:PutObject` permission to the VPC Flow Logs service principal (`delivery.logs.amazonaws.com`) for the cross-account write to succeed. This approach avoids sharing credentials or introducing additional services, maintaining a secure and direct delivery path.

Answer

Use AWS CloudTrail to log flow logs and deliver to the central bucket.

Answer

Share the central bucket's access key with each account to write directly.

Answer

Use Amazon Kinesis Data Firehose to stream flow logs from each account to the central S3 bucket.

Question 8

A security engineer is configuring an S3 bucket policy to restrict access to only requests that originate from a specific VPC endpoint. Which condition key should be used?

Accepted Answer

aws:SourceVpce. The correct condition key is 'aws:SourceVpce' because it allows you to restrict access to an S3 bucket based on the VPC endpoint ID. Option A ('aws:VpcSourceIp') is not a valid AWS condition key. Option B ('aws:SourceVpc') restricts access by VPC ID, not the specific VPC endpoint. Option C ('aws:SourceIp') restricts by client IP address, which is not specific to VPC endpoints. Option D ('aws:SourceVpce') is the correct key to use for restricting access to a specific VPC endpoint.

Answer

aws:VpcSourceIp

Answer

aws:SourceVpc

Answer

aws:SourceIp

Question 9

A security engineer needs to enable VPC Flow Logs to capture traffic metadata. Which THREE components are required to create a VPC Flow Log?

Accepted Answer

A CloudWatch Logs log group to publish the flow logs.. A CloudWatch Logs log group is required because VPC Flow Logs publish traffic metadata to CloudWatch Logs as the default destination. The flow logs are stored as log streams within the specified log group, enabling querying and monitoring via CloudWatch Logs Insights. Without a log group, there is no destination for the flow log records to be sent to.

Answer

An S3 bucket to store the flow logs.

Answer

An Amazon Kinesis Data Firehose delivery stream.

Question 10

A security engineer is investigating a potential data exfiltration incident. The engineer suspects that an attacker is using an Amazon S3 bucket to exfiltrate data. Which AWS service can be used to analyze S3 access logs and detect anomalous patterns?

Accepted Answer

Amazon Athena. Amazon Athena is the correct choice because it allows you to run SQL queries directly against Amazon S3 access logs stored in S3, enabling you to analyze large volumes of log data for anomalous patterns such as unusual data transfer volumes, repeated access from unfamiliar IP ranges, or unexpected object reads. This serverless query service is purpose-built for ad-hoc analysis of structured and semi-structured data in S3 without needing to load data into a separate database, making it ideal for incident response investigations.

Answer

Amazon CloudFront

Answer

AWS Shield

Answer

AWS WAF

Question 11

A security engineer is configuring AWS Config to track changes to security groups in a VPC. The engineer wants to be notified when a security group is modified. Which TWO steps are required to achieve this?

Accepted Answer

Configure an SNS topic and subscribe to it to receive notifications when the Config rule triggers.. Options A and D are correct. To monitor security group changes with AWS Config, you need to create an AWS Config rule (option D) that tracks changes to security groups. To receive notifications when the rule triggers, you configure an SNS topic and subscribe to it (option A). Option B is incorrect because AWS CloudTrail logs API calls to security groups, but Config itself monitors resource configuration changes without requiring CloudTrail. Option C is incorrect because Amazon GuardDuty is a threat detection service, not a configuration change monitor. Option E is incorrect because VPC Flow Logs capture network traffic, not configuration changes. The common pitfall is assuming CloudTrail or GuardDuty is necessary, but Config's built-in change tracking suffices.

Answer

Enable AWS CloudTrail to log security group changes.

Answer

Enable Amazon GuardDuty to detect security group modifications.

Answer

Enable VPC Flow Logs to capture security group activity.

Question 12

A company uses AWS CloudTrail to log management events in all regions. The security team notices that some API calls made by an IAM user are not appearing in the CloudTrail event history. What is the most likely reason?

Accepted Answer

CloudTrail event history only retains events for 90 days; older events are not visible. D is correct because CloudTrail event history only retains the last 90 days of events. If the API calls were made more than 90 days ago, they would no longer appear in the event history, even though the trail itself may still be delivering log files to an S3 bucket for longer-term storage. The security team is likely looking at the event history rather than querying the S3 bucket or using Athena for older events.

Answer

The user used the AWS Management Console, not the CLI

Answer

The trail is configured for a single region only

Answer

The API calls were read-only and excluded by default

Question 13

A company uses AWS Organizations with multiple accounts. The security team wants to centralize the collection of VPC Flow Logs and AWS CloudTrail logs from all accounts into a single Amazon S3 bucket in the management account. The S3 bucket policy must allow cross-account log delivery. Which condition in the bucket policy should be used to restrict log delivery to only the organization's accounts?

Accepted Answer

aws:PrincipalOrgID. The correct condition key is `aws:PrincipalOrgID`, which restricts access to principals (accounts, IAM roles, or users) that are members of the specified AWS Organization. When used in a bucket policy, it ensures that only accounts within the company's organization can deliver logs to the S3 bucket, even if the source account ID changes. Note that `aws:SourceOrgId` is not a valid AWS condition key; `aws:PrincipalOrgID` is the appropriate key for this purpose.

Answer

aws:SourceArn

Answer

aws:SourceOrgId

Answer

aws:SourceAccount

Question 14

A company is using AWS Organizations to manage multiple accounts. The security team wants to ensure that all accounts have AWS CloudTrail enabled in all regions. Which approach should be used?

Accepted Answer

Enable AWS CloudTrail from the master account as an organization trail.. AWS Organizations allows you to create an organization trail from the management account that automatically applies to all member accounts and all regions. This ensures CloudTrail is enabled across the entire organization without requiring per-account configuration, and it centralizes log delivery to a single Amazon S3 bucket for auditing.

Answer

Create an SCP that requires CloudTrail to be enabled.

Answer

Enable CloudTrail in each account using a cross-account IAM role.

Answer

Use AWS Config rules to detect non-compliant accounts and automatically enable CloudTrail.

Question 15

A company is using AWS KMS to encrypt data at rest. The security team needs to ensure that keys cannot be deleted before a retention period. Which THREE steps should be taken? (Choose three.)

Accepted Answer

Enable AWS CloudTrail to log key deletion events.. Options A, B, and E are correct. Enabling CloudTrail to log key deletion events helps audit attempts. Setting CloudWatch alarms on kms:ScheduleKeyDeletion events provides notification. Scheduling key deletion with a waiting period (e.g., 7 days) implements a retention period. Option C is incorrect because IAM policies can prevent deletion but do not enforce a retention period; the question asks to ensure keys cannot be deleted before a retention period, which requires a waiting period, not just denial. Option D is incorrect because automatic rotation does not prevent deletion.

Answer

Create an IAM policy that denies kms:ScheduleKeyDeletion.

Answer

Enable automatic key rotation.

Question 16

A company uses AWS KMS to encrypt objects in an S3 bucket. The security team wants to ensure that only users with the appropriate KMS key permissions can decrypt objects. Which TWO conditions should be included in the S3 bucket policy to enforce this? (Choose TWO.)

Accepted Answer

"Condition": {"StringEquals": {"kms:ViaService": "s3.us-east-1.amazonaws.com"}}. Options A and E are the only distinct conditions that can be used in an S3 bucket policy to enforce that only users with appropriate KMS key permissions can decrypt objects. kms:ViaService restricts the use of the KMS key to requests coming via the S3 service, and kms:EncryptionContext restricts decryption to requests that include the specific S3 bucket ARN. Option C is identical to A and thus does not provide an additional constraint, making it redundant. Options B and D are not valid condition keys for S3 bucket policies.

Answer

"Condition": {"StringEquals": {"kms:KeySpec": "SYMMETRIC_DEFAULT"}}

Answer

"Condition": {"StringEquals": {"kms:ViaService": "s3.us-east-1.amazonaws.com"}}

Answer

"Condition": {"StringEquals": {"kms:GranteePrincipal": "arn:aws:iam::123456789012:role/Admin"}}

Question 17

A company has a requirement to block traffic from specific IP addresses known to be malicious. The company has an Application Load Balancer (ALB) that fronts a web application. The security engineer needs to implement a solution that can block these IP addresses at the edge before they reach the ALB. Which AWS service should be used?

Accepted Answer

Use AWS WAF with an IP set rule to block the malicious IP addresses.. AWS WAF can be associated with an Application Load Balancer and allows you to block traffic based on IP addresses using IP set rules. This enables blocking at the edge before traffic reaches the ALB. Option A is incorrect because security groups are instance-level firewalls and cannot be attached to an ALB. Option B is incorrect as AWS Shield Advanced provides DDoS protection but does not support IP-based blocking by itself. Option C is incorrect because network ACLs operate at the subnet level, not at the ALB level, and cannot block traffic specifically destined for the ALB.

Answer

Configure security groups on the ALB to deny traffic from those IP addresses.

Answer

Enable AWS Shield Advanced and configure rate-based rules.

Answer

Add a network ACL rule to the ALB's subnet to deny the IP addresses.

Question 18

A company requires that all IAM users in the Security team must use multi-factor authentication (MFA) to access the AWS Management Console. The company has enabled MFA for all users, but the Security team administrator reports that some users can still sign in without MFA. Which action should the administrator take to enforce MFA for all sign-ins?

Accepted Answer

Attach an IAM policy that denies all actions if 'aws:MultiFactorAuthPresent' is false.. Attaching an IAM policy that explicitly denies access unless MFA is present will enforce MFA for all actions, including console sign-in. Option A is wrong because the default condition key 'aws:MultiFactorAuthPresent' is not set to 'true' for console sign-in; it is only set for API calls. Option B is wrong because requiring MFA for programmatic access does not affect console sign-in. Option C is wrong because password policy cannot enforce MFA at sign-in.

Answer

Create a new IAM policy that requires MFA for programmatic access only.

Answer

Enable the 'aws:MultiFactorAuthPresent' condition in the IAM password policy.

Answer

Update the password policy to require MFA for all IAM users.

Question 19

A security engineer needs to grant an EC2 instance access to an S3 bucket without storing long-term credentials on the instance. Which approach should the engineer use?

Accepted Answer

Create an IAM role with the required permissions and attach it to the EC2 instance as an instance profile.. An IAM role with an instance profile allows the EC2 instance to obtain temporary credentials from the instance metadata service, avoiding long-term credential storage. Option A is wrong because it stores long-term access keys on the instance. Option B is wrong because SCPs are organization-wide policies, not for individual instances. Option C is wrong because storing credentials in the AMI is insecure and also long-term.

Answer

Generate an access key and secret key for an IAM user and store them in the EC2 instance.

Answer

Use an SCP to allow the EC2 instance to access the S3 bucket.

Answer

Store the credentials in the AMI used to launch the instance.

Question 20

A company is storing sensitive data in Amazon S3 buckets. They want to ensure that all uploaded objects are encrypted at rest using server-side encryption with AWS KMS (SSE-KMS). Which bucket policy statement will enforce this?

Accepted Answer

{"Effect": "Deny", "Principal": "*", "Action": "s3:PutObject", "Resource": "arn:aws:s3:::bucket/*", "Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption": "aws:kms"}}}. It uses a Deny effect with a StringNotEquals condition on the s3:x-amz-server-side-encryption header set to 'aws:kms'. This ensures that any PutObject request that does not include the header specifying SSE-KMS is denied, effectively enforcing that all uploaded objects must be encrypted with AWS KMS. The Deny effect overrides any Allow, making this policy robust against accidental or malicious uploads without the required encryption.

Answer

{"Effect": "Deny", "Principal": "*", "Action": "s3:PutObject", "Resource": "arn:aws:s3:::bucket/*", "Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption": "AES256"}}}

Answer

{"Effect": "Allow", "Principal": "*", "Action": "s3:PutObject", "Resource": "arn:aws:s3:::bucket/*", "Condition": {"StringEquals": {"s3:x-amz-server-side-encryption": "aws:kms"}}}

Answer

{"Effect": "Deny", "Principal": "*", "Action": "s3:PutObject", "Resource": "arn:aws:s3:::bucket/*", "Condition": {"StringNotEquals": {"s3:x-amz-server-side-encryption": "AES256"}}}