Resources:
  # CIS 3.1 a log metric filter and alarm exist for unauthorized API calls 
  CloudWatchLogsMetricFilterCloudTrailUnauthorizedAPICalls:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.errorCode="*UnauthorizedOperation") || ($.errorCode="AccessDenied*")}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: UnauthorizedAPICalls 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailUnauthorizedAPICalls:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *不正なAPIコールを検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-Unauthorized-API-Calls'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      DatapointsToAlarm: 6
      EvaluationPeriods: 60
      MetricName: UnauthorizedAPICalls
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.2 a log metric filter and alarm exist for AWS Management Console sign-in without MFA
  CloudWatchLogsMetricFilterCloudTrailLoginWithoutMFA:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.eventName="ConsoleLogin") && ($.additionalEventData.MFAUsed !="Yes")}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: LoginWithoutMFA 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailLoginWithoutMFA:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *MFAなしのログインを検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-Login-Without-MFA'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: LoginWithoutMFA
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.3 a log metric filter and alarm exist for usage of "root" account 
  CloudWatchLogsMetricFilterCloudTrailForRootAcount:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{$.userIdentity.type="Root" && $.userIdentity.invokedBy NOT EXISTS && $.eventType !="AwsServiceEvent"}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: ForRootAcount 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailForRootAcount:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *ルートアカウントに対する変更を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-For-RootAcount'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: ForRootAcount
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.4 a log metric filter and alarm exist for IAM policy changes 
  CloudWatchLogsMetricFilterCloudTrailIamPolicyChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      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)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: IamPolicyChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailIamPolicyChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *IAMポリシーの変更を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-IamPolicy-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: IamPolicyChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.5 a log metric filter and alarm exist for CloudTrail configuration changes 
  CloudWatchLogsMetricFilterCloudTrailCloudTrailConfigurationChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.eventName=CreateTrail) || ($.eventName=UpdateTrail) || ($.eventName=DeleteTrail) || ($.eventName=StartLogging) || ($.eventName=StopLogging)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: CloudTrailConfigurationChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailCloudTrailConfigurationChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *CloudTrailの設定変更を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-CloudTrailConfiguration-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: CloudTrailConfigurationChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.6 a log metric filter and alarm exist for AWS Management Console authentication failures
  CloudWatchLogsMetricFilterCloudTrailAuthenticationFailuresDetected:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.eventName=ConsoleLogin) && ($.errorMessage="Failed authentication")}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: AuthenticationFailuresDetected 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailAuthenticationFailuresDetected:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *ログイン認証失敗を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-AuthenticationFailures-Detected'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: AuthenticationFailuresDetected
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.7 a log metric filter and alarm exist for disabling or scheduled deletion of customer created CMKs 
  CloudWatchLogsMetricFilterCloudTrailCustomerCreatedCMKsChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.eventSource=kms.amazonaws.com) && (($.eventName=DisableKey) || ($.eventName=ScheduleKeyDeletion))}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: CustomerCreatedCMKsChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailCustomerCreatedCMKsChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *カスタマー作成CMKの無効化もしくは削除を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-CustomerCreatedCMKs-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: CustomerCreatedCMKsChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.8 a log metric filter and alarm exist for S3 bucket policy changes 
  CloudWatchLogsMetricFilterCloudTrailS3BucketPolicyChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties:
      FilterPattern: '{($.eventSource=s3.amazonaws.com) && (($.eventName=PutBucketAcl) || ($.eventName=PutBucketPolicy) || ($.eventName=PutBucketCors) || ($.eventName=PutBucketLifecycle) || ($.eventName=PutBucketReplication) || ($.eventName=DeleteBucketPolicy) || ($.eventName=DeleteBucketCors) || ($.eventName=DeleteBucketLifecycle) || ($.eventName=DeleteBucketReplication))}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: S3BucketPolicyChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailS3BucketPolicyChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *S3のバケットポリシーの変更を検知* しました。'
      AlarmName: !Sub 'Notice-${AWS::StackName}-CloudTrail-S3BucketPolicy-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: S3BucketPolicyChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.9 a log metric filter and alarm exist for AWS Config configuration changes 
  CloudWatchLogsMetricFilterCloudTrailConfigConfigurationChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventSource=config.amazonaws.com) && (($.eventName=StopConfigurationRecorder) || ($.eventName=DeleteDeliveryChannel) || ($.eventName=PutDeliveryChannel) || ($.eventName=PutConfigurationRecorder))}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: ConfigConfigurationChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailConfigConfigurationChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *Configの設定変更を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-ConfigConfiguration-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: ConfigConfigurationChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.10 a log metric filter and alarm exist for changes to Security Group 
  CloudWatchLogsMetricFilterCloudTrailSecurityGroupChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventName=AuthorizeSecurityGroupIngress) || ($.eventName=AuthorizeSecurityGroupEgress) || ($.eventName=RevokeSecurityGroupIngress) || ($.eventName=RevokeSecurityGroupEgress) || ($.eventName=CreateSecurityGroup) || ($.eventName=DeleteSecurityGroup)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: SecurityGroupChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailSecurityGroupChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *セキュリティグループの変更を検知* しました。'
      AlarmName: !Sub 'Warning-${AWS::StackName}-CloudTrail-SecurityGroup-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: SecurityGroupChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.11 a log metric filter and alarm exist for changes to Network Access Control Lists (NACL) 
  CloudWatchLogsMetricFilterCloudTrailNACLChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventName=CreateNetworkAcl) || ($.eventName=CreateNetworkAclEntry) || ($.eventName=DeleteNetworkAcl) || ($.eventName=DeleteNetworkAclEntry) || ($.eventName=ReplaceNetworkAclEntry) || ($.eventName=ReplaceNetworkAclAssociation)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: NACLChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailNACLChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *NACLの変更を検知* しました。'
      AlarmName: !Sub 'Notice-${AWS::StackName}-CloudTrail-NACL-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: NACLChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.12 a log metric filter and alarm exist for changes to network gateways
  CloudWatchLogsMetricFilterCloudTrailNetworkGatewayChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventName=CreateCustomerGateway) || ($.eventName=DeleteCustomerGateway) || ($.eventName=AttachInternetGateway) || ($.eventName=CreateInternetGateway) || ($.eventName=DeleteInternetGateway) || ($.eventName=DetachInternetGateway)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: NetworkGatewayChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailNetworkGatewayChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *ネットワークゲートウェイの変更を検知* しました。'
      AlarmName: !Sub 'Notice-${AWS::StackName}-CloudTrail-NetworkGateway-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: NetworkGatewayChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.13 a log metric filter and alarm exist for route table changes
  CloudWatchLogsMetricFilterCloudTrailRouteTableChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventName=CreateRoute) || ($.eventName=CreateRouteTable) || ($.eventName=ReplaceRoute) || ($.eventName=ReplaceRouteTableAssociation) || ($.eventName=DeleteRouteTable) || ($.eventName=DeleteRoute) || ($.eventName=DisassociateRouteTable)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: RouteTableChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailRouteTableChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *ルートテーブルの変更を検知* しました。'
      AlarmName: !Sub 'Notice-${AWS::StackName}-CloudTrail-RouteTable-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: RouteTableChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching
  # CIS 3.14 a log metric filter and alarm exist for VPC changes 
  CloudWatchLogsMetricFilterCloudTrailVpcChanges:
    Type: 'AWS::Logs::MetricFilter'
    Properties: 
      FilterPattern: '{($.eventName=CreateVpc) || ($.eventName=DeleteVpc) || ($.eventName=ModifyVpcAttribute) || ($.eventName=AcceptVpcPeeringConnection) || ($.eventName=CreateVpcPeeringConnection) || ($.eventName=DeleteVpcPeeringConnection) || ($.eventName=RejectVpcPeeringConnection) || ($.eventName=AttachClassicLinkVpc) || ($.eventName=DetachClassicLinkVpc) || ($.eventName=DisableVpcClassicLink) || ($.eventName=EnableVpcClassicLink)}'
      LogGroupName: !Ref CloudWatchLogsGroupForCloudTrail
      MetricTransformations:
        - MetricName: VpcChanges 
          MetricNamespace: LogMetrics
          MetricValue: '1'
  CloudWatchAlarmMetricFilterCloudTrailVpcChanges:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref SnsTopicARN
      AlarmDescription: '*CloudTrail* が *VPCの変更を検知* しました。'
      AlarmName: !Sub 'Notice-${AWS::StackName}-CloudTrail-Vpc-Changes'
      ComparisonOperator: GreaterThanOrEqualToThreshold
      EvaluationPeriods: 1
      MetricName: VpcChanges
      Namespace: LogMetrics
      OKActions:
        - !Ref SnsTopicARN
      Period: 60
      Statistic: Maximum
      Threshold: 1
      TreatMissingData: notBreaching

Resources:
  SNSAlert:
    Type: 'AWS::SNS::Topic'
    Properties:
      DisplayName: !Sub 'System Notifications from ${AWS::StackName}'
      TopicName: !Sub '${AWS::StackName}-system-notifications'
  SNSAlertTopicPolicy:
    Type: 'AWS::SNS::TopicPolicy'
    Properties:
      Topics: 
        - !Ref SNSAlert
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            # All AWS Services
            Principal:
              AWS: '*'
            Resource: '*'
            Action: 'SNS:Publish'