event.dataset: "aws.cloudtrail"
and event.provider: "sts.amazonaws.com"
and event.action: "GetCallerIdentity"
and event.outcome: "success"
and not aws.cloudtrail.user_identity.type: "AssumedRole"
Install detection rules in Elastic Security
Detect AWS STS GetCallerIdentity API Called for the First Time in the Elastic Security detection engine by installing this rule into your Elastic Stack.
To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).