Using service-linked roles for Amazon GuardDuty

Amazon GuardDuty uses AWS Identity and Access Management (IAM) service-linked roles. A service-linked role is a unique type of IAM role that is linked directly to GuardDuty. Service-linked roles are predefined by GuardDuty and include all the permissions that GuardDuty requires to call other AWS services on your behalf.

A service-linked role makes setting up GuardDuty easier because you don't have to manually add the necessary permissions. GuardDuty defines the permissions of its service-linked role, and unless the permissions are defined otherwise, only GuardDuty can assume the role. The defined permissions include the trust policy and the permissions policy, and that permissions policy can't be attached to any other IAM entity.

GuardDuty supports using service-linked roles in all of the Regions where GuardDuty is available. For more information, see Regions and endpoints.

You can delete the GuardDuty service-linked role only after first disabling GuardDuty in all Regions where it is enabled. This protects your GuardDuty resources because you can't inadvertently remove permission to access them.

For information about other services that support service-linked roles, see AWS services that work with IAM in the IAM User Guide and look for the services that have Yes in the Service-Linked Role column. Choose a Yes with a link to view the service-linked role documentation for that service.

Service-linked role permissions for GuardDuty

GuardDuty uses the service-linked role named AWSServiceRoleForAmazonGuardDuty. This service-linked role allows GuardDuty to retrieve metadata for the EC2 instances in your AWS environment that are involved in potentially suspicious activity. It also allows GuardDuty to include the retrieved EC2 instance metadata in the findings that GuardDuty generates about potentially suspicious activity. The AWSServiceRoleForAmazonGuardDuty service-linked role trusts the guardduty.amazonaws.com service to assume the role.

The permissions policy for the role allows GuardDuty to perform tasks such as:

• Use Amazon EC2 actions to retrieve information about your EC2 instances and images.

• Use Amazon EC2 actions to retrieve information about your EC2 networking components such as VPCs, subnets, and transit gateways.

• Use Amazon S3 actions to retrieve information about S3 buckets and objects.

• Use AWS Organizations actions to describe associated accounts.

The role is configured with the following AWS managed policy, named AWSServiceRoleForAmazonGuardDuty.

        {
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "ec2:DescribeInstances",
        "ec2:DescribeImages",
        "ec2:DescribeVpcEndpoints",
        "ec2:DescribeSubnets",
        "ec2:DescribeVpcPeeringConnections",
        "ec2:DescribeTransitGatewayAttachments"
        "organizations:ListAccounts",
        "organizations:DescribeAccount",
        "s3:GetBucketPublicAccessBlock",
        "s3:GetEncryptionConfiguration",
        "s3:GetBucketTagging",
        "s3:GetAccountPublicAccessBlock",
        "s3:ListAllMyBuckets",
        "s3:GetBucketAcl",
        "s3:GetBucketPolicy",
        "s3:GetBucketPolicyStatus",
      ],
      "Resource": "*"
    }
  ]
}
        
      

The following is the trust policy that is attached to the AWSServiceRoleForAmazonGuardDuty service-linked role:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "guardduty.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

Creating a service-linked role for GuardDuty

The AWSServiceRoleForAmazonGuardDuty service-linked role is automatically created when you enable GuardDuty for the first time or enable GuardDuty in a supported Region where you previously didn't have it enabled. You can also create the AWSServiceRoleForAmazonGuardDuty service-linked role manually using the IAM console, the IAM CLI, or the IAM API.

Important

The service-linked role that is created for the GuardDuty delegated administrator account doesn't apply to the member GuardDuty accounts.

You must configure permissions to allow an IAM entity (such as a user, group, or role) to create, edit, or delete a service-linked role. For the AWSServiceRoleForAmazonGuardDuty service-linked role to be successfully created, the IAM identity that you use GuardDuty with must have the required permissions. To grant the required permissions, attach the following policy to this IAM user, group, or role:

Note

Replace the sample account ID in the example below with your actual AWS account ID.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "guardduty:*"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "iam:CreateServiceLinkedRole"
            ],
            "Resource": "arn:aws:iam::123456789012:role/aws-service-role/guardduty.amazonaws.com/AWSServiceRoleForAmazonGuardDuty",
            "Condition": {
                "StringLike": {
                    "iam:AWSServiceName": "guardduty.amazonaws.com"
                }
            }
        },
        {
            "Effect": "Allow",
            "Action": [
                "iam:PutRolePolicy",
                "iam:DeleteRolePolicy"
            ],
            "Resource": "arn:aws:iam::123456789012:role/aws-service-role/guardduty.amazonaws.com/AWSServiceRoleForAmazonGuardDuty"
        }
    ]
}    
        

For more information about creating the role manually, see Creating a service-linked role in the IAM User Guide.

Editing a service-linked role for GuardDuty

GuardDuty doesn't allow you to edit the AWSServiceRoleForAmazonGuardDuty service-linked role. After you create a service-linked role, you can't change the name of the role because various entities might reference the role. However, you can edit the description of the role using IAM. For more information, see Editing a service-linked role in the IAM User Guide.

Deleting a service-linked role for GuardDuty

If you no longer need to use a feature or service that requires a service-linked role, we recommend that you delete that role. That way you don't have an unused entity that isn't actively monitored or maintained.

Important

You must first disable GuardDuty in all Regions where it is enabled in order to delete the AWSServiceRoleForAmazonGuardDuty.

If the GuardDuty service isn't disabled when you try to delete the service-linked role, the deletion fails. For more information, see Suspending or stopping GuardDuty.

When you disable GuardDuty, the AWSServiceRoleForAmazonGuardDuty is NOT automatically deleted. If you then enable GuardDuty again, it'll start using the existing AWSServiceRoleForAmazonGuardDuty.

To manually delete the service-linked role using IAM

Use the IAM console, the IAM CLI, or the IAM API to delete the AWSServiceRoleForAmazonGuardDuty service-linked role. For more information, see Deleting a service-linked role in the IAM User Guide.