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Microsoft Defender Antivirus exclusions on Windows Server

  • Article

Applies to:

Platforms

  • Windows Server

This article describes types of exclusions that you don't have to define for Microsoft Defender Antivirus:

For a more detailed overview of exclusions, see Manage exclusions for Microsoft Defender for Endpoint and Microsoft Defender Antivirus.

A few important points about exclusions on Windows Server

  • Custom exclusions take precedence over automatic exclusions.
  • Automatic exclusions only apply to real-time protection (RTP) scanning.
  • Automatic exclusions aren't honored during a quick scan, full scan, and custom scan.
  • Custom and duplicate exclusions don't conflict with automatic exclusions.
  • Microsoft Defender Antivirus uses the Deployment Image Servicing and Management (DISM) tools to determine which roles are installed on your computer.
  • Appropriate exclusions must be set for software that isn't included with the operating system.
  • Windows Server 2012 R2 doesn't have Microsoft Defender Antivirus as an installable feature. When you onboard those servers to Defender for Endpoint, you'll install Microsoft Defender Antivirus, and default exclusions for operating system files are applied. However, exclusions for server roles (as specified below) don't apply automatically, and you should configure these exclusions as appropriate. To learn more, see Onboard Windows servers to the Microsoft Defender for Endpoint service.
  • Built-in exclusions and automatic server role exclusions don't appear in the standard exclusion lists that are shown in the Windows Security app.
  • The list of built-in exclusions in Windows is kept up to date as the threat landscape changes. This article lists some, but not all, of the built-in and automatic exclusions.

Automatic server role exclusions

On Windows Server 2016 or later, you shouldn't need to define exclusions for server roles. When you install a role on Windows Server 2016 or later, Microsoft Defender Antivirus includes automatic exclusions for the server role and any files that are added while installing the role.

Windows Server 2012 R2 does not support the automatic exclusions feature. You'll need to define explicit exclusions for any server role and any software that's added after installing the operating system.

Important

  • Default locations could be different than the locations that are described in this article.
  • To set exclusions for software that isn't included as a Windows feature or server role, refer to the software manufacturer's documentation.

Automatic exclusions include:

Hyper-V exclusions

The following table lists the file type exclusions, folder exclusions, and process exclusions that are delivered automatically when you install the Hyper-V role.

Exclusion type Specifics
File types *.vhd
*.vhdx
*.avhd
*.avhdx
*.vsv
*.iso
*.rct
*.vmcx
*.vmrs
Folders %ProgramData%\Microsoft\Windows\Hyper-V
%ProgramFiles%\Hyper-V
%SystemDrive%\ProgramData\Microsoft\Windows\Hyper-V\Snapshots
%Public%\Documents\Hyper-V\Virtual Hard Disks
Processes %systemroot%\System32\Vmms.exe
%systemroot%\System32\Vmwp.exe

SYSVOL files

  • %systemroot%\Sysvol\Domain\*.adm
  • %systemroot%\Sysvol\Domain\*.admx
  • %systemroot%\Sysvol\Domain\*.adml
  • %systemroot%\Sysvol\Domain\Registry.pol
  • %systemroot%\Sysvol\Domain\*.aas
  • %systemroot%\Sysvol\Domain\*.inf
  • %systemroot%\Sysvol\Domain\*Scripts.ini
  • %systemroot%\Sysvol\Domain\*.ins
  • %systemroot%\Sysvol\Domain\Oscfilter.ini

Active Directory exclusions

This section lists the exclusions that are delivered automatically when you install Active Directory Domain Services (AD DS).

NTDS database files

The database files are specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters\DSA Database File

  • %windir%\Ntds\ntds.dit
  • %windir%\Ntds\ntds.pat

The AD DS transaction log files

The transaction log files are specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters\Database Log Files Path

  • %windir%\Ntds\EDB*.log
  • %windir%\Ntds\Res*.log
  • %windir%\Ntds\Edb*.jrs
  • %windir%\Ntds\Ntds*.pat
  • %windir%\Ntds\TEMP.edb

The NTDS working folder

This folder is specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NTDS\Parameters\DSA Working Directory

  • %windir%\Ntds\Temp.edb
  • %windir%\Ntds\Edb.chk
  • %systemroot%\System32\ntfrs.exe
  • %systemroot%\System32\lsass.exe

DHCP Server exclusions

This section lists the exclusions that are delivered automatically when you install the DHCP Server role. The DHCP Server file locations are specified by the DatabasePath, DhcpLogFilePath, and BackupDatabasePath parameters in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DHCPServer\Parameters

  • %systemroot%\System32\DHCP\*\*.mdb
  • %systemroot%\System32\DHCP\*\*.pat
  • %systemroot%\System32\DHCP\*\*.log
  • %systemroot%\System32\DHCP\*\*.chk
  • %systemroot%\System32\DHCP\*\*.edb

DNS Server exclusions

This section lists the file and folder exclusions and the process exclusions that are delivered automatically when you install the DNS Server role.

File and folder exclusions for the DNS Server role

  • %systemroot%\System32\Dns\*\*.log
  • %systemroot%\System32\Dns\*\*.dns
  • %systemroot%\System32\Dns\*\*.scc
  • %systemroot%\System32\Dns\*\BOOT

Process exclusions for the DNS Server role

  • %systemroot%\System32\dns.exe

File and Storage Services exclusions

This section lists the file and folder exclusions that are delivered automatically when you install the File and Storage Services role. The exclusions listed below don't include exclusions for the Clustering role.

  • %SystemDrive%\ClusterStorage
  • %clusterserviceaccount%\Local Settings\Temp
  • %SystemDrive%\mscs

This section lists the file type exclusions, folder exclusions, and the process exclusions that are delivered automatically when you install the Print Server role.

File type exclusions

  • *.shd
  • *.spl

Folder exclusions

This folder is specified in the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Printers\DefaultSpoolDirectory

  • %system32%\spool\printers\*

Process exclusions for the Print Server role

  • spoolsv.exe

Web Server exclusions

This section lists the folder exclusions and the process exclusions that are delivered automatically when you install the Web Server role.

Folder exclusions

  • %SystemRoot%\IIS Temporary Compressed Files
  • %SystemDrive%\inetpub\temp\IIS Temporary Compressed Files
  • %SystemDrive%\inetpub\temp\ASP Compiled Templates
  • %systemDrive%\inetpub\logs
  • %systemDrive%\inetpub\wwwroot

Process exclusions for the Web Server role

  • %SystemRoot%\system32\inetsrv\w3wp.exe
  • %SystemRoot%\SysWOW64\inetsrv\w3wp.exe
  • %SystemDrive%\PHP5433\php-cgi.exe

Turning off scanning of files in the Sysvol\Sysvol folder or the SYSVOL_DFSR\Sysvol folder

The current location of the Sysvol\Sysvol or SYSVOL_DFSR\Sysvol folder and all the subfolders is the file system reparse target of the replica set root. The Sysvol\Sysvol and SYSVOL_DFSR\Sysvol folders use the following locations by default:

  • %systemroot%\Sysvol\Domain
  • %systemroot%\Sysvol_DFSR\Domain

The path to the currently active SYSVOL is referenced by the NETLOGON share and can be determined by the SysVol value name in the following subkey: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Netlogon\Parameters

Exclude the following files from this folder and all its subfolders:

  • *.adm
  • *.admx
  • *.adml
  • Registry.pol
  • Registry.tmp
  • *.aas
  • *.inf
  • Scripts.ini
  • *.ins
  • Oscfilter.ini

Windows Server Update Services exclusions

This section lists the folder exclusions that are delivered automatically when you install the Windows Server Update Services (WSUS) role. The WSUS folder is specified in the registry key HKEY_LOCAL_MACHINE\Software\Microsoft\Update Services\Server\Setup

  • %systemroot%\WSUS\WSUSContent
  • %systemroot%\WSUS\UpdateServicesDBFiles
  • %systemroot%\SoftwareDistribution\Datastore
  • %systemroot%\SoftwareDistribution\Download

Built-in exclusions

Because Microsoft Defender Antivirus is built into Windows, it doesn't require exclusions for operating system files on any version of Windows.

Built-in exclusions include:

The list of built-in exclusions in Windows is kept up to date as the threat landscape changes.

Windows "temp.edb" files

  • %windir%\SoftwareDistribution\Datastore\*\tmp.edb
  • %ProgramData%\Microsoft\Search\Data\Applications\Windows\windows.edb

Windows Update files or Automatic Update files

  • %windir%\SoftwareDistribution\Datastore\*\Datastore.edb
  • %windir%\SoftwareDistribution\Datastore\*\edb.chk
  • %windir%\SoftwareDistribution\Datastore\*\edb\*.log
  • %windir%\SoftwareDistribution\Datastore\*\Edb\*.jrs
  • %windir%\SoftwareDistribution\Datastore\*\Res\*.log

Windows Security files

  • %windir%\Security\database\*.chk
  • %windir%\Security\database\*.edb
  • %windir%\Security\database\*.jrs
  • %windir%\Security\database\*.log
  • %windir%\Security\database\*.sdb

Group Policy files

  • %allusersprofile%\NTUser.pol
  • %SystemRoot%\System32\GroupPolicy\Machine\registry.pol
  • %SystemRoot%\System32\GroupPolicy\User\registry.pol

WINS files

  • %systemroot%\System32\Wins\*\*.chk
  • %systemroot%\System32\Wins\*\*.log
  • %systemroot%\System32\Wins\*\*.mdb
  • %systemroot%\System32\LogFiles\
  • %systemroot%\SysWow64\LogFiles\

File Replication Service (FRS) exclusions

  • Files in the File Replication Service (FRS) working folder. The FRS working folder is specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NtFrs\Parameters\Working Directory

    • %windir%\Ntfrs\jet\sys\*\edb.chk
    • %windir%\Ntfrs\jet\*\Ntfrs.jdb
    • %windir%\Ntfrs\jet\log\*\*.log

  • FRS Database log files. The FRS Database log file folder is specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Ntfrs\Parameters\DB Log File Directory

    • %windir%\Ntfrs\*\Edb\*.log

  • The FRS staging folder. The staging folder is specified in the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NtFrs\Parameters\Replica Sets\GUID\Replica Set Stage

    • %systemroot%\Sysvol\*\Ntfrs_cmp*\

  • The FRS preinstall folder. This folder is specified by the folder Replica_root\DO_NOT_REMOVE_NtFrs_PreInstall_Directory

    • %systemroot%\SYSVOL\domain\DO_NOT_REMOVE_NtFrs_PreInstall_Directory\*\Ntfrs*\

  • The Distributed File System Replication (DFSR) database and working folders. These folders are specified by the registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\DFSR\Parameters\Replication Groups\GUID\Replica Set Configuration File

    Note

    For custom locations, see Opting out of automatic exclusions.

    • %systemdrive%\System Volume Information\DFSR\$db_normal$
    • %systemdrive%\System Volume Information\DFSR\FileIDTable_*
    • %systemdrive%\System Volume Information\DFSR\SimilarityTable_*
    • %systemdrive%\System Volume Information\DFSR\*.XML
    • %systemdrive%\System Volume Information\DFSR\$db_dirty$
    • %systemdrive%\System Volume Information\DFSR\$db_clean$
    • %systemdrive%\System Volume Information\DFSR\$db_lostl$
    • %systemdrive%\System Volume Information\DFSR\Dfsr.db
    • %systemdrive%\System Volume Information\DFSR\*.frx
    • %systemdrive%\System Volume Information\DFSR\*.log
    • %systemdrive%\System Volume Information\DFSR\Fsr*.jrs
    • %systemdrive%\System Volume Information\DFSR\Tmp.edb

Process exclusions for built-in operating system files

  • %systemroot%\System32\dfsr.exe
  • %systemroot%\System32\dfsrs.exe

Opting out of automatic exclusions

In Windows Server 2016 and later, the predefined exclusions delivered by Security intelligence updates only exclude the default paths for a role or feature. If you installed a role or feature in a custom path, or you want to manually control the set of exclusions, make sure to opt out of the automatic exclusions delivered in Security intelligence updates. But keep in mind that the exclusions that are delivered automatically are optimized for Windows Server 2016 and later. See Important points about exclusions before defining your exclusion lists.

Warning

Opting out of automatic exclusions might adversely impact performance, or result in data corruption. Automatic server role exclusions are optimized for Windows Server 2016, Windows Server 2019, and Windows Server 2022.

Because predefined exclusions only exclude default paths, if you move NTDS and SYSVOL folders to another drive or path that is different from the original path, you must add exclusions manually. See Configure the list of exclusions based on folder name or file extension.

You can disable the automatic exclusion lists with Group Policy, PowerShell cmdlets, and WMI.

Use Group Policy to disable the auto-exclusions list on Windows Server 2016, Windows Server 2019, and Windows Server 2022

  1. On your Group Policy management computer, open the Group Policy Management Console. Right-click the Group Policy Object you want to configure, and then select Edit.

  2. In the Group Policy Management Editor go to Computer configuration, and then select Administrative templates.

  3. Expand the tree to Windows components > Microsoft Defender Antivirus > Exclusions.

  4. Double-click Turn off Auto Exclusions, and set the option to Enabled. Then select OK.

Use PowerShell cmdlets to disable the auto-exclusions list on Windows Server

Use the following cmdlets:

Set-MpPreference -DisableAutoExclusions $true

To learn more, see the following resources:

Use Windows Management Instruction (WMI) to disable the auto-exclusions list on Windows Server

Use the Set method of the MSFT_MpPreference class for the following properties:

DisableAutoExclusions

For more information and allowed parameters, see:

Defining custom exclusions

If necessary, you can add or remove custom exclusions. To do that, see the following articles:

See also

Tip

Do you want to learn more? Engage with the Microsoft Security community in our Tech Community: Microsoft Defender for Endpoint Tech Community.