IAM Policy Changes Alarm

AWSTemplateFormatVersion: '2010-09-09'
Description: ''
Resources:
  SnsTopic:
    Type: 'AWS::SNS::Topic'
    Properties:
      Subscription:
        - Endpoint: email@example.com
          Protocol: email
      TopicName: alarm-action
  CloudWatchAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: iam_policy_changes
      AlarmDescription: >-
        A CloudWatch Alarm that triggers when changes are made to IAM policies.
        Events include IAM policy creation/deletion/update operations as well as
        attaching/detaching policies from IAM users, roles or groups.
      MetricName: IAMPolicyEventCount
      Namespace: CloudTrailMetrics
      Statistic: Sum
      Period: '300'
      EvaluationPeriods: '1'
      Threshold: '1'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      AlarmActions:
        - Ref: SnsTopic
      TreatMissingData: notBreaching
  MetricFilter:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      LogGroupName: ''
      FilterPattern: >-
        {($.eventName=DeleteGroupPolicy)||($.eventName=DeleteRolePolicy)||($.eventName=DeleteUserPolicy)||($.eventName=PutGroupPolicy)||($.eventName=PutRolePolicy)||($.eventName=PutUserPolicy)||($.eventName=CreatePolicy)||($.eventName=DeletePolicy)||($.eventName=CreatePolicyVersion)||($.eventName=DeletePolicyVersion)||($.eventName=AttachRolePolicy)||($.eventName=DetachRolePolicy)||($.eventName=AttachUserPolicy)||($.eventName=DetachUserPolicy)||($.eventName=AttachGroupPolicy)||($.eventName=DetachGroupPolicy)}
      MetricTransformations:
        - MetricValue: '1'
          MetricNamespace: CloudTrailMetrics
          MetricName: IAMPolicyEventCount
Parameters: {}
Metadata: {}
Conditions: {}