Introduction

What is Windows Defender Application Control?

Application control is a crucial line of defense for protecting computer systems given today's threat landscape, and it has an inherent advantage over traditional antivirus solutions. Specifically, application control moves away from an application trust model where all applications are assumed trustworthy to one where applications must earn trust in order to run.

Devices where Windows Defender Application control (WDAC) policies are deployed on can either be centrally managed via MDM, Intune etc. or they can be home devices, devices that are private and don't belong to any organization, the computer of someone that you want to keep very much safe and secure so that even the device's owner can't willingly or forcefully compromise themselves, the possibilities are endless.

Important

The WDACConfig module is a one-stop shop for all your Application Control (WDAC) needs. It is scalable, easy to use, enterprise-ready, Azure VM ready and more importantly, it is free and always will be. Check it out here

Windows Defender Application Control (WDAC) wiki posts

• Introduction
• WDAC for Lightly managed device
• WDAC for Fully managed device - Variant 1
• WDAC for Fully managed device - Variant 2
• WDAC for Fully managed device - Variant 3
• WDAC for Fully managed device - Variant 4
• WDAC Notes
• How to Create and Deploy a Signed WDAC Policy
• Fast and Automatic Microsoft Recommended Driver Block Rules updates
• WDAC policy for BYOVD Kernel mode only protection
• EKUs in WDAC, App Control for Business, Policies
• WDAC Rule Levels Comparison and Guide
• Script Enforcement and PowerShell Constrained Language Mode in WDAC App Control Policies
• How to Use Microsoft Defender for Endpoint Advanced Hunting With WDAC App Control

WDACConfig Module

WDACConfig is an advanced PowerShell module designed with the aim of automating Application and File whitelisting in Windows using Windows Defender Application Control. It is available in PowerShell gallery.

Application Control Usage Levels

There are many ways you can utilize Application Control features and here they are sorted by the level of restriction and protection they provide; From top (having the least restriction and protection) to bottom (having the most restriction and protection).

1. Use Microsoft recommended driver block rules.

   • No user action required; The vulnerable driver blocklist is enabled by default for all devices using HVCI or Memory Integrity.
   • The built-in driver blocklist is updated with each new major release of Windows, typically 1-2 times per year.

2. Update Microsoft recommended driver block rules outside of the twice a year schedule.

   • The drivers block list itself is updated more frequently than twice a year schedule, use the WDACConfig Module to setup a scheduled task that keeps the list up-to-date.
3. Use Microsoft recommended block rules + Recommended driver block rules
   • Use the WDACConfig Module to easily deploy the User-Mode Microsoft recommended block rules on your system.
4. Create WDAC policy for Lightly managed devices
   • Microsoft's guide: Create a WDAC policy for lightly managed devices
   • My guide: WDAC for Lightly Managed Devices
5. Use Smart App Control
   • It's just a toggle in Windows Security under App & Browser control. It uses a special kind of WDAC policy that provides more protection than a lightly managed workstation but less protection than a fully managed workstation.
   • It uses both of Microsoft's recommended block rules.
6. Use Smart App Control + Strict Kernel-Mode WDAC Policy
7. Create WDAC policy for Fully managed devices
   • The following scenarios provide the highest protection against any threats from any sources when cryptographically signed and deployed and properly configured.
   • WDAC for Fully managed device - Variant 1
   • WDAC for Fully managed device - Variant 2
   • WDAC for Fully managed device - Variant 3
   • WDAC for Fully managed device - Variant 4
   • Microsoft's guide: Create a WDAC policy for fully managed devices
   • Microsoft's guide: Create a WDAC policy for fixed-workload devices (reference computer)
   • Microsoft's guide: Use audit events to create WDAC policy rules

Methods we can use to create an Application Control policy (WDAC)

• Using PowerShell cmdlets
• Using WDACConfig PowerShell module - Recommended
• Using WDAC Policy Wizard

Plan for Windows Defender Application Control lifecycle policy management

Microsoft provides the following official document to understand the decisions you need to make to establish the processes for managing and maintaining Windows Defender Application Control (WDAC) policies. The rest of them are mentioned below at the Resources section.

Resources

There are a lot more WDAC resources and cmdlets available on Microsoft's websites.

Cmdlets

• New-CIPolicy
• New-CIPolicyRule
• Merge-CIPolicy
• Set-RuleOption
• Set-CIPolicyIdInfo

Documents

• Application Control for Windows
• Understand Windows Defender Application Control policy design decisions
• Deploying Windows Defender Application Control (WDAC) policies
• Use multiple Windows Defender Application Control Policies
• Use audit events to create WDAC policy rules
• Merge Windows Defender Application Control (WDAC) policies
• Understand Windows Defender Application Control (WDAC) policy rules and file rules
• Testing and Debugging AppId Tagging Policies
• Editing existing base and supplemental WDAC policies with the Wizard
• Creating a new Supplemental Policy with the Wizard
• Generate Windows Defender Application Control (WDAC) policies Online
• Windows Defender Application Control (WDAC) example base policies
• Configure the Application Identity service
• Microsoft recommended driver block rules
• Microsoft recommended block rules
• Create a WDAC policy using a reference computer (for fixed-workload devices)
• Create a WDAC policy for fully managed devices
• Create a WDAC policy for lightly managed devices
• Guidance on Creating WDAC Deny Policies
• Hypervisor-protected Code Integrity enablement