Windows 10 Controlled Folder Access Step by Step Guide

Windows 10 Build 16232 and newer builds include a new security feature that can help prevent ransomware, malware, or malicious processes from making changes to files inside folders that you can choose to protect. It is called Windows Defender Controlled Folder Access, and I have been using it for two weeks now, and this article will describe how to set it up, and configure it so that it protects your important files and folders. I strongly recommend anyone using Windows 10 to enable this very helpful feature once they install the Fall Creators Update in a couple of months.

First of all, you are going to have to open up the Windows Defender Security Center, which you can find by going to the tray down at the bottom right of the taskbar and right clicking on the Windows Defender logo and choosing open. You can also click the search icon or the cortana circle and search for defender which will allow you to choose the Windows Defender Security Center. Once you open up the Security Center, you are going to want to find the Virus and Threat protection settings, by clicking the hamburger button on the top left to open up the settings choices and choosing the second item down, which is a shield, (right below the home symbol). This will open up the Antivirus settings, where you will then go to the right down a little and once again click on the Virus and Threat Protection Settings. You need to scroll down until you see Controlled Folder Access.

We are focusing on the Controlled Folder access settings which you can find as you scroll down right after the Automatic Sample Submission On/Off Switch. The first thing you are going to want to do is to change Controlled Folder Access to ON. Next you are going to want to click where it says Protected Folders. This will open Windows Explorer and allow you to choose the folders that you want to be protected. Microsoft has stated that the Windows directory and the libraries are automatically protected, however, just to be sure, I chose Documents, Downloads, my Applications folder, Music, Pictures, and Videos, as well as any external hard drives that are connected to the Windows 10 computer. At first I chose desktop, however I noticed that every time I install an application, the new application is not able to piut shortcuts on the desktop because of the controlled folder access designation, so I eventually removed Desktop from the Protected Folders. The nice thing about this feature is that if an application tries and fails to access a file in a protected folder, you will receive a notification that tells you the location of the executable and where it tries to access. These notifications then stay in the action center, so that if you miss the notification, you will see it later when the Action Center shows up on the right side of the desktop.

For example, I use a program called Internet Download Manager, and it was blocked from accessing the downloads directory. I received a notification that says:
DATA Protection
Unauthorized Changes Blocked C:\Users\james\Downloads\wordpress-com-2-6-0-setup.exe from making changes to the folder C:\Users\james\Desktop

Next step, if the application is safe and you want to allow the application to be able to changed files in the controlled folders, you go down to the next option which says Allow an App through Controlled Folder Access, which brings up Windows Explorer file picker again, where you will find the executable that was blocked and choose it, then accept the UAC prompt. You can go through this as many times as you want, adding any programs that need access to these protected folders.

In summary, Microsoft has finally added a security feature to Windows 10 Fall Creators Update (and any insider preview builds since 16232) that can help prevent ransomware from encryption the files that are inside these controlled folders. The great thing about this feature is that it is brand new, but it works great already, and is configurable enough so that you can whitelist the applications that you need to use to access these folders safely, while any application that Microsoft does not recognize as being safe will be blocked from encrypting any files in these folders. You are not going to want to add every folder, because this will likely cause too many false positives, but you should go through your computer’s hard drives, and move all of your important files into folders that you choose to be Protected Folders. This is a very exciting feature for Security professionals and enterprise I.T., but I am pretty sure that you will need to be running Windows 10 enterprise or Education in order to use this new feature for now.

It is rather simple, and if you are using Windows 10 education or enterprise version I recommend that you immediately turn this on, and set up your controlled folders. I am sure that this feature will be coming to windows server 2016 in the coming insider preview updates, and it is good to see that Microsoft is taking security seriously in Windows 10.

After installing the newest Windows Insider Preview Build 16241, I noticed that when I tried to add new controlled folders or allowed programs with the Windows Defender Security Center, the UI would crash, so I immediately went to PowerShell to check if there were new cmdlets to configure Controlled Folder Access, and there were.

You are now able to use PowerShell to add Controlled Folders, and Applications that are allowed to access and edit files in those folders.