AWS Certified Security – Specialty (SCS-C02) — Question 131

A company uses an external identity provider to allow federation into different AWS accounts. A security engineer for the company needs to identify the federated user that terminated a production Amazon EC2 instance a week ago.

What is the FASTEST way for the security engineer to identify the federated user?

Answer options

• A. Review the AWS CloudTrail event history logs in an Amazon S3 bucket and look for the TerminateInstances event to identify the federated user from the role session name.
• B. Filter the AWS CloudTrail event history for the TerminateInstances event and identify the assumed IAM role. Review the AssumeRoleWithSAML event call in CloudTrail to identify the corresponding username.
• C. Search the AWS CloudTrail logs for the TerminateInstances event and note the event time. Review the IAM Access Advisor tab for all federated roles. The last accessed time should match the time when the instance was terminated.
• D. Use Amazon Athena to run a SQL query on the AWS CloudTrail logs stored in an Amazon S3 bucket and filter on the TerminateInstances event. Identify the corresponding role and run another query to filter the AssumeRoleWithWebIdentity event for the user name.

Correct answer: B

Explanation

The fastest way to identify the federated user who terminated the instance is to filter for the TerminateInstances event and check the AssumeRoleWithSAML event to find the username directly related to the role. Option A does not provide the username directly, option C requires cross-referencing times which could be inefficient, and option D involves multiple queries which may take longer.