SCS-C02 Practice Test 2 — 25 Questions

Question 1

A company uses AWS Lambda functions to process data from an S3 bucket. The security team wants to detect any unauthorized attempts to invoke the Lambda function from outside the company's VPC. The Lambda function is configured to be VPC-enabled and is attached to a VPC with a security group. The team has enabled CloudTrail and VPC Flow Logs. However, they are not seeing any logs for the Lambda invocations in CloudTrail. The team has checked that CloudTrail is logging management events and that the Lambda function is being invoked. What is the most likely reason for the missing CloudTrail logs?

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

Accepted Answer

CloudTrail is not logging Lambda Invoke API calls because they are data events, not management events.. CloudTrail management events do not include Lambda Invoke API calls because these are data events, not management events. To log Lambda invocations, data events must be explicitly enabled in the CloudTrail trail configuration. Option B is incorrect because Lambda functions do not need to be configured to send logs to CloudTrail; CloudTrail automatically captures API calls if configured. Option C is incorrect as the issue is not about configuring data events; the question states data events are not enabled. Option D is incorrect because VPC Flow Logs capture network traffic, not Lambda invocations.

Answer

The Lambda function is not configured to send logs to CloudTrail.

Answer

The CloudTrail trail is not configured to log data events for Lambda.

Answer

VPC Flow Logs are not enabled for the Lambda function's VPC.

Question 2

A company is using Amazon GuardDuty to detect threats. The security team wants to receive alerts for specific findings. Which TWO AWS services can be used to forward GuardDuty findings to a custom application for analysis? (Choose two.)

Accepted Answer

Amazon CloudWatch Events (Amazon EventBridge). Amazon GuardDuty can publish findings to Amazon CloudWatch Events (now part of Amazon EventBridge) as events. These events can then be routed to a custom application via targets like AWS Lambda, SQS, or Kinesis, enabling real-time analysis and alerting. This is the primary, native integration for forwarding GuardDuty findings to downstream systems.

Answer

Amazon Kinesis Data Streams

Answer

Amazon Simple Queue Service (SQS)

Answer

AWS Lambda

Question 3

Refer to the exhibit. A security engineer creates the S3 bucket policy above to allow an IAM role to upload objects only from the corporate network IP range (10.0.0.0/16). However, users report that they can still upload objects from outside the range when assuming the role. What is the most likely cause?

Accepted Answer

The bucket policy uses Allow instead of Deny; an explicit Deny is needed to block requests that do not meet the condition.. An S3 bucket policy with an Allow effect grants access to anyone who meets the condition, but it does not explicitly deny requests that do not meet the condition. In IAM and resource-based policies, an Allow that includes a condition only applies when the condition is true; if the condition is false, the Allow is not evaluated, but other policies (like the IAM role's permissions) may still grant access. To block uploads from outside the corporate IP range, an explicit Deny with the same condition (or a NotIpAddress condition) is required to override any other Allow that might apply.

Answer

The condition key aws:SourceIp does not support the IP range 10.0.0.0/16 because it is a private IP range.

Answer

The IAM role's trust policy does not restrict who can assume the role.

Answer

The resource ARN should not include the trailing /*.

Question 4

Refer to the exhibit. A security engineer ran this AWS CLI command to find when a specific CreateKeyPair API call was made. The command returns no results, even though the engineer knows the call was made. What is the MOST likely reason?

Accepted Answer

The --lookup-attributes parameter has incorrect syntax.. The `--lookup-attributes` parameter requires a JSON structure with an `AttributeKey` and `AttributeValue`. The provided syntax `--lookup-attributes EventName=CreateKeyPair` is invalid; the correct format is `--lookup-attributes AttributeKey=EventName,AttributeValue=CreateKeyPair`. This malformed parameter causes the AWS CLI to fail silently or return no results, even though the API call exists.

Answer

The time range is too narrow.

Answer

The command did not specify a region, so it defaults to us-east-1, but the call was made in a different region.

Answer

The event name should be 'CreateKeypair' (lowercase p).

Question 5

A company uses AWS Organizations to manage multiple accounts. The security team wants to ensure that no resources can be created in a specific AWS Region except for the us-east-1 Region. Which policy type should the security team use?

Accepted Answer

Service control policy (SCP). Service control policies (SCPs) are the correct choice because they allow you to centrally control the maximum available permissions for all accounts in an AWS Organization. By applying an SCP that denies all actions in a specific region (except us-east-1), the security team can enforce a region restriction across all member accounts, regardless of any IAM policies attached to users or roles. SCPs do not grant permissions themselves but act as a guardrail that limits what IAM policies can allow.

Answer

IAM permissions boundary

Answer

IAM policy applied to the root user

Answer

Resource-based policy

Question 6

A company uses Amazon GuardDuty for threat detection. The security team wants to automatically isolate an EC2 instance that is communicating with a known malicious IP address. Which combination of services should be used?

Accepted Answer

GuardDuty -> EventBridge -> Lambda -> modify security group. Amazon GuardDuty generates findings that can be sent to Amazon EventBridge as events. EventBridge can then trigger an AWS Lambda function that modifies the security group associated with the EC2 instance to deny traffic to/from the malicious IP address. This architecture provides a serverless, event-driven response mechanism without polling or additional services.

Answer

GuardDuty -> AWS Config -> Lambda -> modify security group

Answer

GuardDuty -> CloudWatch Alarm -> Lambda -> modify security group

Answer

GuardDuty -> AWS Shield -> modify security group

Answer

GuardDuty -> AWS Systems Manager -> modify security group

Question 7

A company is designing a disaster recovery plan for encrypted Amazon EBS volumes. Which THREE steps are required to ensure that encrypted EBS snapshots can be restored in a different AWS Region?

Accepted Answer

Copy the encrypted snapshot to the target AWS Region. To restore encrypted EBS snapshots in a different AWS Region, you must copy the encrypted snapshot to the target region (B) and ensure the customer managed key (CMK) used for encryption is available in the target region (D). Re-encrypting the snapshot with a CMK in the target region (A) is optional if you want to use a different key, but it is not a required step. Options C and E are incorrect because AWS CloudHSM is not used for EBS encryption and sharing snapshots via AWS RAM does not guarantee key availability.

Answer

Re-encrypt the snapshot with a customer managed key (CMK) in the target region

Answer

Store the encryption key in AWS CloudHSM in the target region

Answer

Share the snapshot with the target region using AWS RAM

Question 8

A company uses S3 to store sensitive customer data. The security team requires that all objects uploaded to S3 be encrypted at rest using server-side encryption with AWS KMS managed keys (SSE-KMS). A developer reports that some objects are being stored unencrypted. What is the MOST effective way to enforce this requirement?

Accepted Answer

Use a bucket policy to deny s3:PutObject if encryption is not set to aws:kms. A bucket policy with a Deny effect on s3:PutObject when the condition `s3:x-amz-server-side-encryption` is not equal to `aws:kms` enforces SSE-KMS for all uploads. Option A is incorrect because default encryption using SSE-S3 can be overridden by the PUT request, and it does not enforce KMS. Option C is incorrect because SCPs apply at the account or organizational unit level, not to individual buckets, and are less direct than bucket policies. Option D is incorrect because requiring the `x-amz-server-side-encryption` header alone does not mandate the value `aws:kms`; a requester could set it to `AES256` (SSE-S3).

Answer

Enable default encryption on the bucket using SSE-S3

Answer

Use an SCP to deny s3:PutObject without encryption

Answer

Set a bucket policy to require the x-amz-server-side-encryption header

Question 9

Refer to the exhibit. A security engineer reviews this CloudFormation template. The bucket is intended to be private. What is the security issue in the configuration?

Accepted Answer

The PublicAccessBlock configuration is missing the BlockPublicPolicy setting.. The PublicAccessBlock configuration in the template is missing the BlockPublicPolicy setting. Without BlockPublicPolicy enabled, a bucket policy that grants public read access (Effect: Allow, Principal: *, Action: s3:GetObject) can be applied to the bucket, overriding the intended private configuration. The other PublicAccessBlock settings (BlockPublicAcls, IgnorePublicAcls, RestrictPublicBuckets) do not block bucket policies; only BlockPublicPolicy does. The security issue is that the bucket policy, though present, would be blocked if BlockPublicPolicy were enabled, but since it is missing, the bucket becomes publicly accessible.

Answer

The bucket does not have versioning enabled.

Answer

The bucket policy grants public read access to the bucket, which overrides the PublicAccessBlock configuration.

Answer

The bucket policy uses an incorrect resource ARN.

Question 10

A security engineer is configuring a VPC for a highly sensitive application. The VPC must not have a route to the internet, but the application needs to periodically download security patches from a specific domain (patches.example.com). Which solution meets these requirements with minimal operational overhead?

Accepted Answer

Use a VPC endpoint for Amazon S3 and DynamoDB to download patches.. It uses VPC endpoints for Amazon S3 (and optionally DynamoDB) to provide private connectivity to AWS services without requiring an internet gateway. By storing the security patches in an S3 bucket with a custom domain alias (e.g., patches.example.com), the application can download patches through the VPC endpoint, meeting the requirement of no internet route and minimizing operational overhead. Options A and D require an internet gateway, which creates a route to the internet. Option C does not provide access to an external domain like patches.example.com.

Answer

Launch a proxy server in a public subnet and configure the application to use the proxy.

Answer

Create a VPC interface endpoint for AWS Systems Manager and use Systems Manager Patch Manager to apply patches.

Answer

Deploy a NAT gateway in a public subnet and add a route to the NAT gateway for the private subnet.

Question 11

A company has a requirement to retain CloudTrail logs for 7 years for compliance. The logs are stored in an S3 bucket. The security team needs to ensure that logs are not deleted before the retention period ends, even by users with full S3 permissions. Which action should be taken?

Accepted Answer

Enable S3 Object Lock in Compliance mode on the bucket with a retention period of 7 years.. S3 Object Lock in Compliance mode prevents any user, including the root user, from overwriting or deleting objects until the retention period expires. This meets the requirement to retain CloudTrail logs for 7 years, even against users with full S3 permissions, because Compliance mode cannot be bypassed or removed by any user.

Answer

Enable MFA Delete on the bucket and require MFA for all delete operations.

Answer

Enable S3 Versioning and set a lifecycle policy to expire noncurrent versions after 7 years.

Answer

Create a bucket policy that denies s3:DeleteObject for all users.

Question 12

A company runs a critical web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application processes sensitive customer data. The Security team has enabled VPC Flow Logs, CloudTrail, and GuardDuty. Recently, the team received a GuardDuty finding indicating a potential SSH brute force attack originating from an external IP address 203.0.113.50 targeting one of the EC2 instances. The Security Engineer needs to automatically isolate the affected instance and capture forensic evidence for analysis. The company has strict requirements: the instance must be isolated immediately, and a snapshot of the EBS volume must be taken before any remediation actions are taken. The instance is part of an Auto Scaling group, and the Security Engineer wants to minimize manual intervention. The Security Engineer has access to AWS Systems Manager and AWS Lambda. Which combination of steps should the Security Engineer implement to meet the requirements?

Accepted Answer

Configure Amazon EventBridge to detect the GuardDuty finding and invoke an AWS Lambda function. The Lambda function first calls the EC2 CreateSnapshot API to capture a forensic snapshot of the instance's EBS volume. Then, it uses AWS Systems Manager Automation to run a pre-defined automation document that isolates the instance by modifying the instance's security group to only allow traffic from a trusted management IP, and then stops the instance.. It uses EventBridge to directly detect the GuardDuty finding, which triggers a Lambda function that first takes an EBS snapshot (forensic capture) via the CreateSnapshot API before any remediation. Then it uses Systems Manager Automation to isolate the instance by modifying the security group to allow only a trusted management IP and stops the instance, ensuring isolation without destroying the instance. This sequence satisfies the strict requirement that a snapshot must be taken before any remediation actions, and it minimizes manual intervention by automating the entire response.

Answer

Use AWS Systems Manager to automatically connect to the instance via EC2 Instance Connect, run commands to capture forensic data, and then modify the security group to deny all inbound traffic.

Answer

Create a CloudWatch Logs metric filter on the VPC Flow Logs for the attacker IP. When the metric breaches a threshold, trigger an SNS topic that runs an AWS Systems Manager Automation document to isolate the instance and take an EBS snapshot.

Answer

Configure a CloudWatch Events rule to detect the GuardDuty finding and invoke an AWS Lambda function. The Lambda function terminates the EC2 instance and then takes a snapshot of the EBS volume for forensic analysis.

Question 13

A company is designing a VPC with public and private subnets. The web servers in the public subnets must be accessible from the internet on port 443, but the database servers in the private subnets should only be accessible from the web servers on port 3306. Which combination of security group rules and network ACL rules should be used to meet these requirements with the least administrative overhead?

Accepted Answer

Use security groups for all tiers; add an inbound rule to the database security group allowing traffic from the web security group on port 3306.. Security groups are stateful and support referencing other security groups as a source, which allows you to permit traffic from the web security group to the database security group on port 3306 without needing to specify IP addresses. This approach minimizes administrative overhead as security group rules are automatically applied to all instances associated with the group, and changes propagate without updating network ACLs or CIDR ranges. The web security group can have an inbound rule allowing HTTPS (port 443) from the internet (0.0.0.0/0), while the database security group only allows inbound MySQL/Aurora (port 3306) from the web security group, meeting the access requirements precisely.

Answer

Use security groups for all tiers; add an inbound rule to the web security group allowing internet traffic on port 443, and add an outbound rule to the web security group allowing traffic to the database security group on port 3306.

Answer

Use security groups for the web tier and network ACLs for the database tier; add an inbound rule to the database network ACL allowing traffic from the web subnet CIDR on port 3306.

Answer

Use security groups for the web tier and network ACLs for the database tier; add an inbound rule to the database network ACL allowing all traffic from the web security group.

Question 14

Refer to the exhibit. A security engineer created this S3 bucket policy to allow CloudTrail to deliver logs. However, log delivery is failing. What is the most likely cause?

Accepted Answer

The bucket policy does not allow s3:GetBucketAcl. CloudTrail requires the S3 bucket policy to grant the `s3:GetBucketAcl` permission to the CloudTrail service principal (`cloudtrail.amazonaws.com`) so that it can verify the bucket's ACL before delivering logs. Without this permission, CloudTrail cannot confirm it has write access, causing log delivery to fail. The missing `s3:GetBucketAcl` action is the most likely cause because the policy must explicitly allow both `s3:PutObject` and `s3:GetBucketAcl` for the service to function.

Answer

The bucket is not in the same region as the trail

Answer

The bucket policy does not specify a condition

Answer

The bucket is encrypted with SSE-KMS

Question 15

A security engineer is troubleshooting why CloudTrail is not delivering logs to an S3 bucket. The bucket policy allows CloudTrail to write objects, and the trail is configured with the correct bucket name. However, no log files appear. What is the most likely cause?

Accepted Answer

The S3 bucket uses AWS KMS server-side encryption (SSE-KMS) and the KMS key policy does not grant CloudTrail permission to use the key.. When CloudTrail is configured to deliver logs to an S3 bucket that uses SSE-KMS, CloudTrail must have explicit permission to use the KMS key for encrypting the log files. Even if the bucket policy allows CloudTrail to write objects, the KMS key policy must grant the `kms:GenerateDataKey` and `kms:Decrypt` actions to the CloudTrail service principal. Without these permissions, CloudTrail cannot encrypt the logs, and delivery fails silently—no log files appear.

Answer

The S3 bucket has an S3 Object Lock configuration that prevents writes.

Answer

The S3 bucket is in a different AWS Region from the trail.

Answer

CloudTrail is not enabled in the AWS Region where the S3 bucket resides.

Question 16

A company is using Amazon EC2 instances in a VPC with a security group that allows inbound SSH from 0.0.0.0/0. A security engineer needs to restrict SSH access to only the company's public IP range (203.0.113.0/24) while maintaining all other existing rules. What is the MOST efficient way to accomplish this?

Accepted Answer

Modify the existing security group rule to change the source from 0.0.0.0/0 to 203.0.113.0/24.. Modifying the existing security group rule's source from 0.0.0.0/0 to 203.0.113.0/24 directly restricts inbound SSH to the company's public IP range without affecting any other rules. Security groups are stateful and rule changes apply immediately, making this the most efficient approach as it requires only a single edit to the existing rule.

Answer

Disable SSH and use AWS Systems Manager Session Manager to connect to instances.

Answer

Create a network ACL with an inbound rule allowing SSH from 203.0.113.0/24 and deny all other traffic.

Answer

Create a new security group rule allowing SSH from 203.0.113.0/24 and keep the existing rule.

Question 17

A security engineer needs to protect data in transit between an EC2 instance and an RDS database. The RDS database uses SSL/TLS certificates. What is the MOST secure way to ensure that the connection is encrypted?

Accepted Answer

Download the RDS CA certificate to the EC2 instance and configure the database client to use SSL and verify the certificate.. Downloading the RDS CA certificate to the EC2 instance and configuring the database client to use SSL with certificate verification ensures that the data in transit is encrypted and that the server's identity is verified, preventing man-in-the-middle attacks. Option A is incorrect because a self-signed certificate without proper verification does not provide a trusted chain of identity. Option B is incorrect because encryption at rest protects data stored on disk, not data in transit. Option D is incorrect because IAM policies can require SSL but cannot enforce the actual encryption of the connection; the client must still be configured to use SSL.

Answer

Configure the EC2 instance to use a self-signed certificate for SSL connections.

Answer

Enable encryption at rest on the RDS instance to automatically encrypt in-transit traffic.

Answer

Create an IAM policy that requires SSL connections to the RDS endpoint.

Question 18

A security engineer discovers an Amazon GuardDuty finding of type 'UnauthorizedAccess:EC2/SSHBruteForce' for an EC2 instance. The instance is part of an Auto Scaling group and has a public IP address. What is the MOST effective immediate step to mitigate the threat?

Accepted Answer

Detach the instance from the Auto Scaling group and terminate it.. The instance is compromised and part of an Auto Scaling group. Detaching it first prevents the Auto Scaling group from immediately replacing it with a new instance that might inherit the same vulnerability, allowing for forensic analysis. Terminating it after detachment stops the SSH brute force attack at its source without risking automatic re-provisioning of a similarly exposed instance.

Answer

Modify the network ACL to block SSH traffic from the attacker's IP.

Answer

Terminate the instance without detaching it from the Auto Scaling group.

Answer

Update the security group to restrict SSH access to known IP addresses.

Question 19

A company wants to restrict access to an Amazon S3 bucket so that only users from a specific AWS account can upload objects. Which policy mechanism should be used?

Accepted Answer

Create a bucket policy with a condition that checks the aws:SourceAccount condition key.. A bucket policy with the `aws:SourceAccount` condition key allows you to restrict access to a specific AWS account. When users from the allowed account upload objects, the condition evaluates the source account ID, ensuring only requests originating from that account are permitted. This is the recommended approach for cross-account access control in S3, as it directly enforces the account-level restriction at the bucket policy level.

Answer

Attach an IAM policy to the bucket that denies access to all users except those from the allowed account.

Answer

Generate a pre-signed URL for each upload request.

Answer

Configure the bucket ACL to grant access only to the allowed account's canonical user ID.

Question 20

An organization uses AWS Organizations with hundreds of accounts. The security team wants to automatically respond to a specific GuardDuty finding by isolating the affected EC2 instance. What is the recommended architecture?

Accepted Answer

Use EventBridge to trigger a Lambda function in the delegated administrator account, which assumes an IAM role in the affected account to isolate the instance.. It follows the recommended architecture for cross-account automated response to GuardDuty findings. EventBridge in the delegated administrator account captures the finding and triggers a Lambda function, which then assumes an IAM role (using STS AssumeRole) in the affected member account to perform the isolation. This pattern centralizes management while respecting the security boundary between accounts.

Answer

Configure GuardDuty to invoke a Lambda function in the affected account directly.

Answer

Use EventBridge to send the finding to a Step Functions workflow that isolates the instance.

Answer

Use AWS Systems Manager Automation to isolate the instance across accounts.