SCS-C02 Security Logging and Monitoring Practice Question

A security engineer is reviewing CloudTrail logs and notices an event with the key 'eventType' set to 'AwsServiceEvent'. What does this indicate?

⚠ Common exam trap

Many candidates confuse 'AwsServiceEvent' with API calls made by a user or assume it indicates an error, when in fact it specifically denotes actions initiated by AWS services themselves, not by human users or errors.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

The event was initiated by an AWS service.

In AWS CloudTrail, the 'eventType' field indicates the source of the event. When set to 'AwsServiceEvent', it means the event was generated by an AWS service on behalf of the customer, such as automatic backups, scaling actions, or health checks. This is distinct from events initiated by a user or federated identity, which would have 'eventType' set to 'AwsApiCall' or 'AwsConsoleSignIn'.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
The event was initiated by an IAM user via the AWS Management Console.
Why it's wrong here
If the event had been initiated by an IAM user through the AWS Management Console, the eventType would be AwsConsoleAction (for actions taken directly in the console) or AwsApiCall (for API calls made via the console), and the userIdentity element would show the IAM user's ARN, accessKeyId, and sessionContext with webId federation details. AwsServiceEvent specifically indicates that the action was performed by an AWS service, not by a human user, so this option is incorrect.
✓
The event was initiated by an AWS service.
Why this is correct
When the eventType is AwsServiceEvent, it means the event was generated by an AWS service performing an action on a resource, often on behalf of a customer or as part of automatic operations. The userIdentity is typically null or represents a service role, and the eventSource field identifies the service (e.g., ec2.amazonaws.com, s3.amazonaws.com). This is the correct explanation because AwsServiceEvent is the only eventType that directly maps to an action initiated by an AWS service, not by a user or a console sign-in.
✗
The event was a sign-in event from the AWS Management Console.
Why it's wrong here
A CloudTrail sign-in event is recorded with the eventType AwsConsoleSignin and includes details like the user's IAM entity, source IP, and MFA status in the userIdentity and responseElements fields. These sign-in events are entirely distinct from AwsServiceEvent, which represents an AWS service performing an API operation, not a user authenticating to the console. Therefore, this option is incorrect because the eventType in question does not correspond to any sign-in action.
✗
The event type is an error in the log.
Why it's wrong here
AwsServiceEvent is a standard, valid eventType defined by CloudTrail; it is not an error indicator. CloudTrail does not use eventType to signal errors — instead, errors are captured in fields like errorCode and errorMessage on the event, while the eventType simply categorizes whether the event was an API call, a console action, a sign-in, or a service event. The presence of AwsServiceEvent means the event was successful (or at least recorded) as a service-initiated action, not that the log contains an error.

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SCS-C02 Security Logging and Monitoring Practice Question

Why each option matters

Option-by-option breakdown

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