Proactive controls - AWS Control Tower

Proactive controls

Proactive controls are optional controls implemented with AWS CloudFormation hooks. Proactive controls fall into four main Categories.

These controls are referred to as proactive because they check your resources – before the resources are deployed – to determine whether the new resources will comply with the controls that are activated in your environment.

In the AWS Control Tower console, you can view the controls in groups according to their assigned categories, which are:

  • Control objectives: Specific purposes for implementing controls in your environment.

  • Frameworks: Industry-standard compliance frameworks.

  • Services: The AWS services that the control may govern.

  • Groups: Groups of controls designed to help you meet a specific policy standard.

In this reference guide, the proactive controls are categorized according to their associated AWS services.


You must apply an elective, SCP-based control with the identifier CT.CLOUDFORMATION.PR.1 before you can activate proactive controls on an OU. See CT.CLOUDFORMATION.PR.1. If this SCP is not activated, you'll see an error message directing you to enable this control as a prerequisite, or showing it as a dependency for other proactive controls.

Behavior of proactive controls

Proactive controls check resources whenever those resources are created or updated by means of AWS CloudFormation stack operations. Specifically, these proactive controls are implemented as preCreate and preUpdate AWS CloudFormation hook handlers. As a consequence, these controls may not affect requests that are made directly to services through the AWS console, through AWS APIs, or through other means such as AWS SDKs, or other Infrastructure-as-Code (IaC) tools. For more information about when preCreate and preUpdate hooks operate, see AWS CloudFormation hooks.


Proactive controls evaluate strings passed into the AWS CloudFormation hook within the targetNames property. Secure strings and secrets are not resolved before they are sent to the hook, which prevents the proactive control from evaluating the string. For more information about how the targetNames are passed to hooks, see AWS CloudFormation Hooks structure overview.

When you follow an example template to set up a test for a proactive control in your environment, be aware that the template is created to test one specific control only. Other controls may not receive a PASS rating for that template. This behavior is expected. We recommend that you test proactive controls individually before you enable them in your environment.


It is important to know that some proactive controls in AWS Control Tower do not operate in certain AWS Regions where AWS Control Tower is available, because those Regions do not support the required underlying functionality for AWS CloudFormation hooks. As a result, when you deploy a proactive control through AWS Control Tower, the control may not be operating in all Regions that you govern with AWS Control Tower.

You can view the Regions for each proactive control in the AWS Control Tower console.