AWS IAM AdministratorAccess policy was applied to a group

Goal

Detect when the AdministratorAccess policy is attached to an AWS IAM group.

Strategy

This rule allows you to monitor CloudTrail and detect if an attacker has attached the AWS managed policy AdministratorAccess to an AWS IAM group using the AttachGroupPolicy API call.

Triage and response

  1. Determine if {{@userIdentity.session_name}} should have made a {{@evt.name}} API call.
  2. If the API call was not made by the user:
  • Rotate user credentials.
  • Determine what other API calls were made by the user.
  • Remove the AdministratorAccess policy from the {{@requestParameters.groupName}} group using the aws-cli command detach-group-policy.
  1. If the API call was made legitimately by the user:
  • Determine if the group {{@requestParameters.groupName}} requires the AdministratorAccess policy to perform the intended function.
  • Advise the user to find the least privileged policy that allows the group to operate as intended.