Information
This policy setting configures Common Log File System (CLFS) logfile authentication. Logfile authentication provides the ability for the CLFS driver to detect malicious modifications made to logfiles.
The recommended state for this setting is: Enabled.
CLFS is a security feature which hardens logfile parsing. If modifications to logfiles are detected, CLFS will consider the logfile unsafe for parsing and return an error to the caller. It is also able to detect modifications by writing authentication codes to logfiles which combines file data with a system-unique cryptographic key.
Solution
To establish the recommended configuration via GP, set the following UI path to Enabled :
Computer Configuration\Policies\Administrative Templates\System\Filesystem\Enable / disable CLFS logfile authentication
Note: This Group Policy path is provided by the Group Policy template FileSys.admx/adml that is included with the Microsoft Windows 11 Release 25H2 Administrative Templates (or newer).
Impact:
None - this is the default behavior.
Warning: Logfiles that were created on other systems will fail to open as these contain authentication codes created using a system-unique cryptographic key. To open a logfile that was created on another system an administrator must first use the fsutil.exe clfs authenticate command to correct the authentication codes.