SCS-C01 : AWS Certified Security – Specialty : Part 05

SCS-C01 : AWS Certified Security – Specialty : Part 05

1. Due to new compliance requirements, a Security Engineer must enable encryption with customer-provided keys on corporate data that is stored in DynamoDB. The company wants to retain full control of the encryption keys.

   Which DynamoDB feature should the Engineer use to achieve compliance’?

   • Use AWS Certificate Manager to request a certificate. Use that certificate to encrypt data prior to uploading it to DynamoDB.
   • Enable S3 server-side encryption with the customer-provided keys. Upload the data to Amazon S3, and then use S3Copy to move all data to DynamoDB
   • Create a KMS master key. Generate per-record data keys and use them to encrypt data prior to uploading it to DynamoDS. Dispose of the cleartext and encrypted data keys after encryption without storing.
   • Use the DynamoDB Java encryption client to encrypt data prior to uploading it to DynamoDB.

2. A Security Engineer must design a system that can detect whether a file on an Amazon EC2 host has been modified. The system must then alert the Security Engineer of the modification.

   What is the MOST efficient way to meet these requirements?

   • Install antivirus software and ensure that signatures are up-to-date. Configure Amazon CloudWatch alarms to send alerts for security events.
   • Install host-based IDS software to check for file integrity. Export the logs to Amazon CloudWatch Logs for monitoring and alerting.
   • Export system log files to Amazon S3. Parse the log files using an AWS Lambda function that will send alerts of any unauthorized system login attempts through Amazon SNS.
   • Use Amazon CloudWatch Logs to detect file system changes. If a change is detected, automatically terminate and recreate the instance from the most recent AMI. Use Amazon SNS to send notification of the event.

3. A company has multiple VPCs in their account that are peered, as shown in the diagram. A Security Engineer wants to perform penetration tests of the Amazon EC2 instances in all three VPCs.
   How can this be accomplished? (Choose two.)

   

   • Deploy a pre-authorized scanning engine from the AWS Marketplace into VPC B, and use it to scan instances in all three VPCs. Do not complete the penetration test request form.
   • Deploy a pre-authorized scanning engine from the Marketplace into each VPC, and scan instances in each VPC from the scanning engine in that VPC. Do not complete the penetration test request form.
   • Create a VPN connection from the data center to VPC A. Use an on-premises scanning engine to scan the instances in all three VPCs. Complete the penetration test request form for all three VPCs.
   • Create a VPN connection from the data center to each of the three VPCs. Use an on-premises scanning engine to scan the instances in each VPC. Do not complete the penetration test request form.
   • Create a VPN connection from the data center to each of the three VPCs. Use an on-premises scanning engine to scan the instances in each VPC. Complete the penetration test request form for all three VPCs.

4. The Security Engineer is managing a traditional three-tier web application that is running on Amazon EC2 instances. The application has become the target of increasing numbers of malicious attacks from the Internet.

   What steps should the Security Engineer take to check for known vulnerabilities and limit the attack surface? (Choose two.)

   • Use AWS Certificate Manager to encrypt all traffic between the client and application servers.
   • Review the application security groups to ensure that only the necessary ports are open.
   • Use Elastic Load Balancing to offload Secure Sockets Layer encryption.
   • Use Amazon Inspector to periodically scan the backend instances.
   • Use AWS Key Management Services to encrypt all the traffic between the client and application servers.

5. For compliance reasons, an organization limits the use of resources to three specific AWS regions. It wants to be alerted when any resources are launched in unapproved regions.

   Which of the following approaches will provide alerts on any resources launched in an unapproved region?

   • Develop an alerting mechanism based on processing AWS CloudTrail logs.
   • Monitor Amazon S3 Event Notifications for objects stored in buckets in unapproved regions.
   • Analyze Amazon CloudWatch Logs for activities in unapproved regions.
   • Use AWS Trusted Advisor to alert on all resources being created.

6. A company runs an application on AWS that needs to be accessed only by employees. Most employees work from the office, but others work remotely or travel.

   How can the Security Engineer protect this workload so that only employees can access it?

   • Add each employee’s home IP address to the security group for the application so that only those users can access the workload.
   • Create a virtual gateway for VPN connectivity for each employee, and restrict access to the workload from within the VPC.
   • Use a VPN appliance from the AWS Marketplace for users to connect to, and restrict workload access to traffic from that appliance.
   • Route all traffic to the workload through AWS WAF. Add each employee’s home IP address into an AWS WAF rule, and block all other traffic.

7. A Systems Engineer is troubleshooting the connectivity of a test environment that includes a virtual security appliance deployed inline. In addition to using the virtual security appliance, the Development team wants to use security groups and network ACLs to accomplish various security requirements in the environment.

   What configuration is necessary to allow the virtual security appliance to route the traffic?

   • Disable network ACLs.
   • Configure the security appliance’s elastic network interface for promiscuous mode.
   • Disable the Network Source/Destination check on the security appliance’s elastic network interface
   • Place the security appliance in the public subnet with the internet gateway

8. A Security Architect is evaluating managed solutions for storage of encryption keys. The requirements are:

   -Storage is accessible by using only VPCs.
   -Service has tamper-evident controls.
   -Access logging is enabled.
   -Storage has high availability.

   Which of the following services meets these requirements?

   • Amazon S3 with default encryption
   • AWS CloudHSM
   • Amazon DynamoDB with server-side encryption
   • AWS Systems Manager Parameter Store

9. An AWS account includes two S3 buckets: bucket1 and bucket2. The bucket2 does not have a policy defined, but bucket1 has the following bucket policy:

   

   In addition, the same account has an IAM User named “alice”, with the following IAM policy.

   

   Which buckets can user “alice” access?

   • Bucket1 only
   • Bucket2 only
   • Both bucket1 and bucket2
   • Neither bucket1 nor bucket2

10. An organization has three applications running on AWS, each accessing the same data on Amazon S3. The data on Amazon S3 is server-side encrypted by using an AWS KMS Customer Master Key (CMK).

    What is the recommended method to ensure that each application has its own programmatic access control permissions on the KMS CMK?

    • Change the key policy permissions associated with the KMS CMK for each application when it must access the data in Amazon S3.
    • Have each application assume an IAM role that provides permissions to use the AWS Certificate Manager CMK.
    • Have each application use a grant on the KMS CMK to add or remove specific access controls on the KMS CMK.
    • Have each application use an IAM policy in a user context to have specific access permissions on the KMS CMK.

11. The Security Engineer is given the following requirements for an application that is running on Amazon EC2 and managed by using AWS CloudFormation templates with EC2 Auto Scaling groups:

    -Have the EC2 instances bootstrapped to connect to a backend database.
    -Ensure that the database credentials are handled securely.
    -Ensure that retrievals of database credentials are logged.

    Which of the following is the MOST efficient way to meet these requirements?

    • Pass databases credentials to EC2 by using CloudFormation stack parameters with the property set to true. Ensure that the instance is configured to log to Amazon CloudWatch Logs.
    • Store database passwords in AWS Systems Manager Parameter Store by using SecureString parameters. Set the IAM role for the EC2 instance profile to allow access to the parameters.
    • Create an AWS Lambda that ingests the database password and persists it to Amazon S3 with server-side encryption. Have the EC2 instances retrieve the S3 object on startup, and log all script invocations to syslog.
    • Write a script that is passed in as UserData so that it is executed upon launch of the EC2 instance. Ensure that the instance is configured to log to Amazon CloudWatch Logs.

12. A company has two AWS accounts, each containing one VPC. The first VPC has a VPN connection with its corporate network. The second VPC, without a VPN, hosts an Amazon Aurora database cluster in private subnets. Developers manage the Aurora database from a bastion host in a public subnet as shown in the image.

    

    A security review has flagged this architecture as vulnerable, and a Security Engineer has been asked to make this design more secure. The company has a short deadline and a second VPN connection to the Aurora account is not possible.
    How can the Security Engineer securely set up the bastion host?

    • Move the bastion host to the VPC with VPN connectivity. Create a VPC peering relationship between the bastion host VPC and Aurora VPC.
    • Create an SSH port forwarding tunnel on the Developer’s workstation to the bastion host to ensure that only authorized SSH clients can access the bastion host.
    • Move the bastion host to the VPC with VPN connectivity. Create a cross-account trust relationship between the bastion VPC and Aurora VPC, and update the Aurora security group for the relationship.
    • Create an AWS Direct Connect connection between the corporate network and the Aurora account, and adjust the Aurora security group for this connection.

13. An organization operates a web application that serves users globally. The application runs on Amazon EC2 instances behind an Application Load Balancer. There is an Amazon CloudFront distribution in front of the load balancer, and the organization uses AWS WAF. The application is currently experiencing a volumetric attack whereby the attacker is exploiting a bug in a popular mobile game.

    The application is being flooded with HTTP requests from all over the world with the User-Agent set to the following string: Mozilla/5.0 (compatible; ExampleCorp; ExampleGame/1.22; Mobile/1.0)

    What mitigation can be applied to block attacks resulting from this bug while continuing to service legitimate requests?

    • Create a rule in AWS WAF rules with conditions that block requests based on the presence of ExampleGame/1.22 in the User-Agent header
    • Create a geographic restriction on the CloudFront distribution to prevent access to the application from most geographic regions
    • Create a rate-based rule in AWS WAF to limit the total number of requests that the web application services.
    • Create an IP-based blacklist in AWS WAF to block the IP addresses that are originating from requests that contain ExampleGame/1.22 in the User-Agent header.

14. Some highly sensitive analytics workloads are to be moved to Amazon EC2 hosts. Threat modeling has found that a risk exists where a subnet could be maliciously or accidentally exposed to the internet.

    Which of the following mitigations should be recommended?

    • Use AWS Config to detect whether an Internet Gateway is added and use an AWS Lambda function to provide auto-remediation.
    • Within the Amazon VPC configuration, mark the VPC as private and disable Elastic IP addresses.
    • Use IPv6 addressing exclusively on the EC2 hosts, as this prevents the hosts from being accessed from the internet.
    • Move the workload to a Dedicated Host, as this provides additional network security controls and monitoring.

15. A Developer who is following AWS best practices for secure code development requires an application to encrypt sensitive data to be stored at rest, locally in the application, using AWS KMS. What is the simplest and MOST secure way to decrypt this data when required?

    • Request KMS to provide the stored unencrypted data key and then use the retrieved data key to decrypt the data.
    • Keep the plaintext data key stored in Amazon DynamoDB protected with IAM policies. Query DynamoDB to retrieve the data key to decrypt the data
    • Use the Encrypt API to store an encrypted version of the data key with another customer managed key. Decrypt the data key and use it to decrypt the data when required.
    • Store the encrypted data key alongside the encrypted data. Use the Decrypt API to retrieve the data key to decrypt the data when required.

16. A Security Administrator at a university is configuring a fleet of Amazon EC2 instances. The EC2 instances are shared among students, and non-root SSH access is allowed. The Administrator is concerned about students attacking other AWS account resources by using the EC2 instance metadata service.

    What can the Administrator do to protect against this potential attack?

    • Disable the EC2 instance metadata service.
    • Log all student SSH interactive session activity.
    • Implement iptables-based restrictions on the instances.
    • Install the Amazon Inspector agent on the instances.

17. An organization receives an alert that indicates that an EC2 instance behind an ELB Classic Load Balancer has been compromised.

    What techniques will limit lateral movement and allow evidence gathering?

    • Remove the instance from the load balancer and terminate it.
    • Remove the instance from the load balancer, and shut down access to the instance by tightening the security group.
    • Reboot the instance and check for any Amazon CloudWatch alarms.
    • Stop the instance and make a snapshot of the root EBS volume.

18. A Development team has asked for help configuring the IAM roles and policies in a new AWS account. The team using the account expects to have hundreds of master keys and therefore does not want to manage access control for customer master keys (CMKs).

    Which of the following will allow the team to manage AWS KMS permissions in IAM without the complexity of editing individual key policies?

    • The account’s CMK key policy must allow the account’s IAM roles to perform KMS EnableKey.
    • Newly created CMKs must have a key policy that allows the root principal to perform all actions.
    • Newly created CMKs must allow the root principal to perform the kms CreateGrant API operation.
    • Newly created CMKs must mirror the IAM policy of the KMS key administrator.

19. An Amazon EC2 instance is part of an EC2 Auto Scaling group that is behind an Application Load Balancer (ALB). It is suspected that the EC2 instance has been compromised.

    Which steps should be taken to investigate the suspected compromise? (Choose three.)

    • Detach the elastic network interface from the EC2 instance.
    • Initiate an Amazon Elastic Block Store volume snapshot of all volumes on the EC2 instance.
    • Disable any Amazon Route 53 health checks associated with the EC2 instance.
    • De-register the EC2 instance from the ALB and detach it from the Auto Scaling group.
    • Attach a security group that has restrictive ingress and egress rules to the EC2 instance.
    • Add a rule to an AWS WAF to block access to the EC2 instance.

20. A company has five AWS accounts and wants to use AWS CloudTrail to log API calls. The log files must be stored in an Amazon S3 bucket that resides in a new account specifically built for centralized services with a unique top-level prefix for each trail. The configuration must also enable detection of any modification to the logs.

    Which of the following steps will implement these requirements? (Choose three.)

    • Create a new S3 bucket in a separate AWS account for centralized storage of CloudTrail logs, and enable “Log File Validation” on all trails.
    • Use an existing S3 bucket in one of the accounts, apply a bucket policy to the new centralized S3 bucket that permits the CloudTrail service to use the “s3: PutObject” action and the “s3 GetBucketACL” action, and specify the appropriate resource ARNs for the CloudTrail trails.
    • Apply a bucket policy to the new centralized S3 bucket that permits the CloudTrail service to use the “s3 PutObject” action and the “s3 GelBucketACL” action, and specify the appropriate resource ARNs for the CloudTrail trails.
    • Use unique log file prefixes for trails in each AWS account.
    • Configure CloudTrail in the centralized account to log all accounts to the new centralized S3 bucket.
    • Enable encryption of the log files by using AWS Key Management Service