{
  "source": [
    "aws.sts"
  ],
   "detail-type": [
     "AWS API Call via CloudTrail"
   ],
   "detail": {
     "eventSource": ["sts.amazonaws.com"],
     "eventName": ["AssumeRole"],
     "requestParameters": {
       "roleArn": ["arn:aws:iam::1111111111:role/RoleName"]
     }
   }
}