Encrypted administrator password retrieved for Windows EC2 instance

Goal

Detect a user attempting to retrieve the encrypted Administrator password for a Windows EC2 instance.

Strategy

This rule allows you to monitor CloudTrail and detect if an attacker has attempted to retrieve the encrypted Administrator password for a Windows EC2 instance using the GetPasswordData 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.
  1. If the API call was made by the user:
  • Determine if this user should be accessing this EC2 instance.
  • If Yes, advise the user to speak with the instance owner to resolve the error.
  • If No, see if other API calls were made by the user and determine if they warrant further investigation.