From csoonline.com
Microsoft added a cool, new feature to Microsoft Windows client and server products. Controlled Folder Access gives you another way to mitigate the impact of ransomware. Of course, you should enable with careful testing and custom configuration because it will likely block legitimate programs, some of which could be critical to your computer or organization.
Added with the Windows 10 Fall Creators Update in 2017 now in Windows Server 2019, Controlled Folder Access is another welcomed, built-in (but not-enabled-by-default) Windows security feature to help prevent ransomware from damaging your files and folders. It even prevents unauthorized writes to disk sectors and files stored in memory. In a nutshell, Controlled Folder Access will try to prevent “unsafe” applications from modifying protected files, folders and files stored in memory. The default protected folders include Windows system files and the built-in, common default document and content folders.