How do I monitor IAM events and set up event notifications with AWS CloudFormation?

Last updated: 2020-11-18

I want to monitor AWS Identity and Access Management (IAM) activity with AWS CloudFormation. For example, I want to receive an email notification whenever a certain IAM event occurs.

Short description

You can use the AWS CloudFormation template in the following resolution to monitor IAM events and set up notifications with Amazon CloudWatch Events. 

Consider the following:

  • You must deploy the template in the US East (N. Virginia) - us-east-1 AWS Region.
  • You can modify the AWS::SNS::Topic resource to include additional email addresses.
  • You can edit the AWS::Events::Rule resource to add or remove additional API calls.

Resolution

The following template includes the AWS::Events::Rule resource that contains the EventPattern property. You can use the EventPattern property to give different event sources and API calls the ability to add or restrict specific events for your use case. Each API call has different parameters and information in the events. It isn't possible to create one-size-fits-all events rule. The following sample template provides only two rules that group together many different API calls. However, you can use as many rules as you need to create emails or notifications for different API calls. You can customize and define which API calls to monitor and define customized emails and information for each call.

1.    Copy the following JSON or YAML version of the template, and then update it with the values for your environment.

JSON:

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "Monitor IAM events with CloudWatch Events rules with AWS CloudFormation. This Stack must be deployed in 'us-east-1' (IAM).",
    "Parameters": {
        "EmailList": {
            "Type": "String",
            "Description": "Email to notify!",
            "AllowedPattern": "[a-zA-Z0-9]+@[a-zA-Z0-9]+\\.[a-zA-Z]+",
            "Default": "mail@company.com"
        },
        "SNSTopicName": {
            "Type": "String",
            "Description": "Name for the notification topic.",
            "AllowedPattern": "[a-zA-Z0-9_-]+",
            "Default": "iam-monitoring-topic"
        },
        "MonitorStatus": {
            "Type": "String",
            "Description": "Enable / Disable monitor.",
            "AllowedValues": [
                "ENABLED",
                "DISABLED"
            ],
            "Default": "ENABLED"
        }
    },
    "Resources": {
        "SNSMonitoringTopic": {
            "Type": "AWS::SNS::Topic",
            "Properties": {
                "Subscription": [
                    {
                        "Endpoint": {
                            "Ref": "EmailList"
                        },
                        "Protocol": "email"
                    }
                ],
                "TopicName": {
                    "Fn::Sub": "${AWS::StackName}-${SNSTopicName}"
                }
            }
        },
        "SNSMonitoringTopicTopicPolicy": {
            "Type": "AWS::SNS::TopicPolicy",
            "Properties": {
                "Topics": [
                    {
                        "Ref": "SNSMonitoringTopic"
                    }
                ],
                "PolicyDocument": {
                    "Version": "2012-10-17",
                    "Statement": [
                        {
                            "Sid": "SnsIAMTopicPolicy",
                            "Effect": "Allow",
                            "Principal": {
                                "Service": "events.amazonaws.com"
                            },
                            "Action": [
                                "sns:Publish"
                            ],
                            "Resource": {
                                "Ref": "SNSMonitoringTopic"
                            }
                        },
                        {
                            "Sid": "AllowAccessToTopicOwner",
                            "Effect": "Allow",
                            "Principal": {
                                "AWS": "*"
                            },
                            "Action": [
                                "sns:GetTopicAttributes",
                                "sns:SetTopicAttributes",
                                "sns:AddPermission",
                                "sns:RemovePermission",
                                "sns:DeleteTopic",
                                "sns:Subscribe",
                                "sns:ListSubscriptionsByTopic",
                                "sns:Publish",
                                "sns:Receive"
                            ],
                            "Resource": {
                                "Ref": "SNSMonitoringTopic"
                            },
                            "Condition": {
                                "StringEquals": {
                                    "AWS:SourceOwner": {
                                        "Ref": "AWS::AccountId"
                                    }
                                }
                            }
                        }
                    ]
                }
            }
        },
        "EventRulePolicyMonitor": {
            "Type": "AWS::Events::Rule",
            "Properties": {
                "Name": {
                    "Fn::Sub": "${AWS::StackName}-policy-monitor"
                },
                "Description": "This CloudWatch Event Rule will capture IAM API Calls and events related to creation and deletion of policies.\n",
                "State": {
                    "Ref": "MonitorStatus"
                },
                "EventPattern": {
                    "source": [
                        "aws.iam"
                    ],
                    "detail-type": [
                        "AWS API Call via CloudTrail"
                    ],
                    "detail": {
                        "eventSource": [
                            "iam.amazonaws.com"
                        ],
                        "eventName": [
                            "CreatePolicy",
                            "DeletePolicy",
                            "PutGroupPolicy",
                            "DeleteGroupPolicy",
                            "PutRolePolicy",
                            "DeleteRolePolicy",
                            "PutUserPolicy",
                            "DeleteUserPolicy",
                            "CreatePolicyVersion",
                            "DeletePolicyVersion",
                            "AttachRolePolicy",
                            "DetachRolePolicy",
                            "AttachUserPolicy",
                            "DetachUserPolicy",
                            "AttachGroupPolicy",
                            "DetachGroupPolicy"
                        ]
                    }
                },
                "Targets": [
                    {
                        "Arn": {
                            "Ref": "SNSMonitoringTopic"
                        },
                        "Id": "iam-policy-monitor",
                        "InputTransformer": {
                            "InputPathsMap": {
                                "eventName": "$.detail.eventName",
                                "policyName": "$.detail.requestParameters.policyName",
                                "policyArn": "$.detail.requestParameters.policyArn",
                                "eventTime": "$.detail.eventTime",
                                "userIdentity": "$.detail.userIdentity.arn",
                                "sourceIPAddress": "$.detail.sourceIPAddress"
                            },
                            "InputTemplate": "\"API Call '<eventName>' was issued on policy '<policyName><policyArn>'. This occurred at '<eventTime>' and was initiated by '<userIdentity>' from IP '<sourceIPAddress>'. Please review the details here: https://console.aws.amazon.com/iam/home?region=us-east-1#/policies/<policyArn>$jsonEditor?section=attached_entities .\"\n"
                        }
                    }
                ]
            }
        },
        "EventRulePrincipalsMonitor": {
            "Type": "AWS::Events::Rule",
            "Properties": {
                "Name": {
                    "Fn::Sub": "${AWS::StackName}-principals-monitor"
                },
                "Description": "This CloudWatch Event Rule will capture IAM API Calls and events related to creation and deletion of users, groups and roles.",
                "State": {
                    "Ref": "MonitorStatus"
                },
                "EventPattern": {
                    "source": [
                        "aws.iam"
                    ],
                    "detail-type": [
                        "AWS API Call via CloudTrail"
                    ],
                    "detail": {
                        "eventSource": [
                            "iam.amazonaws.com"
                        ],
                        "eventName": [
                            "CreateUser",
                            "CreateGroup",
                            "CreateRole",
                            "UpdateUser",
                            "UpdateGroup",
                            "UpdateRole",
                            "DeleteUser",
                            "DeleteGroup",
                            "DeleteRole"
                        ]
                    }
                },
                "Targets": [
                    {
                        "Arn": {
                            "Ref": "SNSMonitoringTopic"
                        },
                        "Id": "iam-user-monitor",
                        "InputTransformer": {
                            "InputPathsMap": {
                                "eventName": "$.detail.eventName",
                                "userName": "$.detail.requestParameters.userName",
                                "roleName": "$.detail.requestParameters.roleName",
                                "groupName": "$.detail.requestParameters.groupName",
                                "eventTime": "$.detail.eventTime",
                                "userIdentity": "$.detail.userIdentity.arn",
                                "sourceIPAddress": "$.detail.sourceIPAddress"
                            },
                            "InputTemplate": "\"API Call '<eventName>' was issued on '<userName><roleName><groupName>'. This occurred at '<eventTime>' and was initiated by '<userIdentity>' from IP '<sourceIPAddress>'. \"\n"
                        }
                    }
                ]
            }
        }
    }
}

YAML:

AWSTemplateFormatVersion: 2010-09-09
Description: >
             - Monitor IAM events with CloudWatch Events rules with AWS CloudFormation.
             - This Stack must be deployed in 'us-east-1' (IAM).


Parameters:

  EmailList:
    Type: String
    Description: "Email to notify!"
    AllowedPattern: '[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-zA-Z]+'
    Default: "mail@company.com"

  SNSTopicName:
    Type: String
    Description: "Name for the notification topic."
    AllowedPattern: '[a-zA-Z0-9_-]+'
    Default: "iam-monitoring-topic"

  MonitorStatus:
    Type: String
    Description: "Enable / Disable monitor."
    AllowedValues:
      - ENABLED
      - DISABLED
    Default: ENABLED


Resources:

  SNSMonitoringTopic:
    Type: AWS::SNS::Topic
    Properties:
      Subscription:
        - Endpoint: !Ref EmailList
          Protocol: email
      TopicName: !Sub ${AWS::StackName}-${SNSTopicName}

  SNSMonitoringTopicTopicPolicy:
    Type: AWS::SNS::TopicPolicy
    Properties:
      Topics:
        - !Ref SNSMonitoringTopic
      PolicyDocument:
          Version: '2012-10-17'
          Statement:
          - Sid: SnsIAMTopicPolicy
            Effect: Allow
            Principal:
              Service: events.amazonaws.com
            Action: [  'sns:Publish' ]
            Resource: !Ref SNSMonitoringTopic
          - Sid: AllowAccessToTopicOwner
            Effect: Allow
            Principal:
              AWS: '*'
            Action: [  'sns:GetTopicAttributes',
                       'sns:SetTopicAttributes',
                       'sns:AddPermission',
                       'sns:RemovePermission',
                       'sns:DeleteTopic',
                       'sns:Subscribe',
                       'sns:ListSubscriptionsByTopic',
                       'sns:Publish',
                       'sns:Receive' ]
            Resource: !Ref SNSMonitoringTopic
            Condition:
              StringEquals:
                'AWS:SourceOwner': !Ref 'AWS::AccountId'

  EventRulePolicyMonitor:
    Type: AWS::Events::Rule
    Properties:
      Name: !Sub ${AWS::StackName}-policy-monitor
      Description: >
        This CloudWatch Event Rule will capture IAM API Calls and
        events related to creation and deletion of policies.
      State: !Ref MonitorStatus
      EventPattern:
        source:
           - aws.iam
        detail-type:
          - AWS API Call via CloudTrail
        detail:
          eventSource:
            - iam.amazonaws.com
          eventName:
            - CreatePolicy
            - DeletePolicy
            - PutGroupPolicy
            - DeleteGroupPolicy
            - PutRolePolicy
            - DeleteRolePolicy
            - PutUserPolicy
            - DeleteUserPolicy
            - CreatePolicyVersion
            - DeletePolicyVersion
            - AttachRolePolicy
            - DetachRolePolicy
            - AttachUserPolicy
            - DetachUserPolicy
            - AttachGroupPolicy
            - DetachGroupPolicy
      Targets:
        - Arn:
            Ref: SNSMonitoringTopic
          Id: iam-policy-monitor
          InputTransformer:
            InputPathsMap:
              eventName: $.detail.eventName
              policyName: $.detail.requestParameters.policyName
              policyArn: $.detail.requestParameters.policyArn
              eventTime: $.detail.eventTime
              userIdentity: $.detail.userIdentity.arn
              sourceIPAddress: $.detail.sourceIPAddress
            InputTemplate: >
                "API Call '<eventName>' was issued on policy '<policyName><policyArn>'. This occurred at '<eventTime>' and was initiated by '<userIdentity>' from IP '<sourceIPAddress>'. Please review the details here: https://console.aws.amazon.com/iam/home?region=us-east-1#/policies/<policyArn>$jsonEditor?section=attached_entities ."

  EventRulePrincipalsMonitor:
    Type: AWS::Events::Rule
    Properties:
      Name: !Sub ${AWS::StackName}-principals-monitor
      Description: >
        This CloudWatch Event Rule will capture IAM API Calls and
        events related to creation and deletion of users, groups
        and roles.
      State: !Ref MonitorStatus
      EventPattern:
        source:
           - aws.iam
        detail-type:
          - AWS API Call via CloudTrail
        detail:
          eventSource:
            - iam.amazonaws.com
          eventName:
            - CreateUser
            - CreateGroup
            - CreateRole
            - UpdateUser
            - UpdateGroup
            - UpdateRole
            - DeleteUser
            - DeleteGroup
            - DeleteRole
      Targets:
        - Arn:
            Ref: SNSMonitoringTopic
          Id: iam-user-monitor
          InputTransformer:
            InputPathsMap:
              eventName: $.detail.eventName
              userName: $.detail.requestParameters.userName
              roleName: $.detail.requestParameters.roleName
              groupName: $.detail.requestParameters.groupName
              eventTime: $.detail.eventTime
              userIdentity: $.detail.userIdentity.arn
              sourceIPAddress: $.detail.sourceIPAddress
            InputTemplate: >
                "API Call '<eventName>' was issued on '<userName><roleName><groupName>'. This occurred at '<eventTime>' and was initiated by '<userIdentity>' from IP '<sourceIPAddress>'. "

2.    Deploy your template using either the AWS CloudFormation console or the AWS Command Line Interface (AWS CLI):

AWS CloudFormation console

1.    Download the template.

2.    Open the AWS CloudFormation console.

3.    From the AWS Region selector in the navigation bar, choose us-east-1.

4.    Choose Create stack, and then choose With new resources (standard).

5.    In the Specify template section, choose Upload a template file.

6.    Choose Choose file, select the template that you downloaded in step 1, and then choose Next.

7.    In the Stack name section, for Stack name, enter a name for your stack.

8.    In the Parameters section, for EmailList, enter the email address where you want to receive notifications.

9.    For MonitorStatus, choose ENABLED.

10.    For SNSTopicName, leave the default name, or choose your own name for an Amazon Simple Notification Service (Amazon SNS) topic.

11.    Complete the rest of the steps in the setup wizard, and then choose Create stack.

12.    Check your inbox (using the email address that you entered in step 8) for a confirmation email, and then follow the email instructions to confirm your subscription.

AWS CLI

Note: If you receive errors when running AWS CLI commands, make sure that you’re using the most recent AWS CLI version.

1.    Download the template, and then name the template sample-event-rule-iam-sns.yaml.

2.    Set up the AWS CLI.

3.    Open a command line in your operating system, and go to the folder where your template is located.

4.    Run the following command:

aws cloudformation --region=us-east-1 \
                   create-stack \
                   --stack-name iam-sample-monitor \
                   --template-body file://sample-event-rule-iam-sns.yaml \
                   --parameters \
                   ParameterKey=EmailList,ParameterValue="mail@company.com"

Note: Replace mail@company.com with the email that you want to receive notifications.

5.    Check your inbox (using the email address that you entered in step 4) for a confirmation email, and then follow the email instructions to confirm your subscription.

Test the monitoring notification

1.    Open the IAM console.

2.    Create a testing policy.

3.    Check your email for a notification about the event. You will receive an email similar to the following:

API Call 'CreatePolicy' was issued on policy 'test-policy'. 
This occurred at '2020-11-13T00:00:00Z' and was initiated by 'arn:aws:sts::123456789012:assumed-role/your-role' from IP 'X.Y.Z.T'. 
Please review the details here: https://console.aws.amazon.com/iam/home?region=us-east-1#/policies/$jsonEditor?section=attached_entities.

Did this article help?


Do you need billing or technical support?