Bulk exporting and importing WMI filters for Group Policy

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Mike again. Here is an updated version of the blog post which was originally published on the Group Policy blog. Check it out!

Did you know you can import/export WMI filters using GPMC? However, your export is limited to one filter at a time – filter to a single .mof file. You then take the exported .mof file to a different domain and use GPMC to import each file. This is great when you only have one or two WMI filters. What about if you have 15 or 20? No worries! You can do this using the LDIFDE utility. (This is a long but detailed explanation).

First, you need to find the WMI Filter you want to export (and eventually import). GPMC writes WMI filters in the Domain partition at:

CN=SOM,CN=WMIPolicy,CN=System,DC=contoso,DC=com.

The LDAP filter you use to return all WMI filters is (objectclass=msWMI-Som) . You can narrow the number of returned items if you know the name of the WMI Filter by using
(&(objectclass=msWMI-Som)(msWMI-Name=filtername)) . You can lean more about LDAP search filter syntax from MSDN (https://msdn2.microsoft.com/en-us/library/aa746475.aspx). The following sample command line gives you and idea of how to export the WMI Filter:

LDIFDE -f output.txt –d “dc=contoso.com” –r ”( objectclass=msWMI-Som)” –p subtree

In the example above, -f designates the name of the output file that stores the exported WIM filter objects. Next, -d designates the based distinguished name; that is, where the search for objects starts. In this example, it starts at the beginning of the domain. The –r is an inclusive LDAP search filter. In this example we only want objects of the class
msWMI-Som returned by the query. Lastly, the –p designates that type of search we want to use. A subtree search means the search begins at the designated base distinguished name and searches the entire depth of the tree for objects matching the designated filter—similar to using dir /s on a directory when searching for a file.

Your options may vary. If you have problems exporting the items then add –j . (one dash, the letter J, a space, and one period) to the command line to create a log file in the current folder. A successful output.txt file looks similar to the following:

dn: CN={1154EFFC-0090-4F23-8865-C8D555BF696E},CN=SOM,CN=WMIPolicy,CN=System,DC=contoso,DC=com
changetype: add
objectClass: top
objectClass: msWMI-Som
cn: {1154EFFC-0090-4F23-8865-C8D555BF696E}
distinguishedName:
CN={1154EFFC-0090-4F23-8865-C8D555BF696E},CN=SOM,CN=WMIPolicy,CN=System,DC=con
toso,DC=com
instanceType: 4
whenCreated: 20070808151246.0Z
whenChanged: 20070808151246.0Z
uSNCreated: 40979
uSNChanged: 40979
showInAdvancedViewOnly: TRUE
name: {1154EFFC-0090-4F23-8865-C8D555BF696E}
objectGUID:: EPDEbOIaGEWyX3Z/b+eiKw==
objectCategory: CN=ms-WMI-Som,CN=Schema,CN=Configuration,DC=contoso,DC=com
msWMI-Author: Administrator@CONTOSO.COM
msWMI-ChangeDate: 20070618142622.740000-000
msWMI-CreationDate: 20070618142257.735000-000
msWMI-ID: {1154EFFC-0090-4F23-8865-C8D555BF696E}
msWMI-Name: Imported WMIFilter2
msWMI-Parm1: This is the description for the filter
msWMI-Parm2:
1;3;10;45;WQL;root\CIMv2;Select * from win32_timezone where bias =-300;

Once you successfully export the WMI Filters; you then need to prepare the output file for import.

clip_image002 To prepare the output file for importing:

1. First, save the file as another file name.

2. Then, you need to download the GUIDGEN utility (this is not so important when importing the WMI filter into a different domain). As a reference, this is a guid: {DF380E6C-DB23-44ed-9BF6-435559503347}.

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    • You MUST change the guids to import into the same domain or it will NOT import.

3. Change the guid (to include open and closing curly braces) in the DN, CN, distinguishedname, name, and msWMI-ID attributes (use the same guid in each of these attributes).

4. If importing into a different domain, change the LDAP path to reflect the new domain in the dn, distinguishedName, and objectCategory attributes. Only change the domain portion of the LDAP path.

5. Next, you need to remark out the whenCreated, whenChanged, USNcreated, USNChanged, objectguid, msWMI-ChangeDate,  and msWMI-CreationDate attributes. Do this by inserting the # character and a space at the beginning of the line for each of the listed attributes.

6. Optionally, you can change the text displayed in msWMI-Name, msWMI-Author, and msWMI-Parm1 attributes.

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    • msWMI-Name is the display name of the WMI Filter shown in GPMC. 
    • msWMI-Author is the UPN format for the person creating the WMI filter.
    • msWMI-Parm1 is the description text shown for the WMI filter in GPMC.

The final file should look similar to the following.

dn: CN={4464D2C2-9063-4953-AE6F-A0D231EBF3CD},CN=SOM,CN=WMIPolicy,CN=System,DC=fabrikam,DC=com changetype: add
objectClass: top
objectClass: msWMI-Som
cn: {4464D2C2-9063-4953-AE6F-A0D231EBF3CD} distinguishedName:
CN={4464D2C2-9063-4953-AE6F-A0D231EBF3CD},CN=SOM,CN=WMIPolicy,CN=System,DC=fabrikam,DC=com instanceType: 4
# whenCreated: 20070618142257.0Z
# whenChanged: 20070618142622.0Z
# uSNCreated: 26483
# uSNChanged: 26485
showInAdvancedViewOnly: TRUE
name: {4464D2C2-9063-4953-AE6F-A0D231EBF3CD} # objectGUID:: 7sA6lK0PVE2fGNOSDTS5Kw==
objectCategory: CN=ms-WMI-Som,CN=Schema,CN=Configuration,DC=fabrikam,DC=com msWMI-Author: Administrator@fabrikam.COM # msWMI-ChangeDate: 20070618142622.740000-000
# msWMI-CreationDate: 20070618142257.735000-000
msWMI-ID: {4464D2C2-9063-4953-AE6F-A0D231EBF3CD} msWMI-Name: Imported WMIFilter2
msWMI-Parm1: This is the description for the filter
msWMI-Parm2:
1;3;10;45;WQL;root\CIMv2;Select * from win32_timezone where bias =-300;

You’re almost ready to import the WMI filters. However, importing or adding a WMI Filter object into AD is a system only operation. You need to enable system only changes on a domain controller for a successful LDIFDE import. To do this, on the domain controller you are using for importing, open the registry editor and create the following registry value.

Key: HKLM\System\CurrentControlSet\Services\NTDS\Parameters
Value Name: Allow System Only Change
Value Type: REG_DWORD
Value Data: 1 (Binary)

Next, you’ll need to reboot the domain controller to activate the new setting. Once the domain controller is rebooted, you can use LDIFDE to import the file into AD. Use the following command:

LDIFDE -i –f input.txt

If you have problems then add –j . (one dash, the letter J, a space, and one period) to the command line to create a log file in the local folder. Once the import is complete you should delete the System Only Registry key and reboot the domain controller to deactivate the setting. A successful import looks similar to the following.

Connecting to "hq-con-dc-01.fabrikam.com"
Logging in as current user using SSPI
Importing directory from file "import-wmi.ldf"

Loading entries
1: CN={4464D2C2-9063-4953-AE6F-A0D231EBF3CD},CN=SOM,CN=WMIPolicy,CN=System,DC=fabrikam,DC=com
Entry DN: CN={4464D2C2-9063-4953-AE6F-A0D231EBF3CD},CN=SOM,CN=WMIPolicy,CN=System,DC=fabrikam,DC=com
changetype: add
Attribute 0) objectClass:top msWMI-Som
Attribute 1) cn:{4464D2C2-9063-4953-AE6F-A0D231EBF3CD}
Attribute 2) distinguishedName:CN={4464D2C2-9063-4953-AE6F-A0D231EBF3CD},CN=SOM,CN=WMIPolicy,CN=System,DC=fabrikam,DC=com
Attribute 3) instanceType:4
Attribute 4) showInAdvancedViewOnly:TRUE
Attribute 5) name:{4464D2C2-9063-4953-AE6F-A0D231EBF3CD}
Attribute 6) objectCategory:CN=ms-WMI-Som,CN=Schema,CN=Configuration,DC=fabrikam,DC=com
Attribute 7) msWMI-Author:Administrator@FABRIKAM.COM
Attribute 8) msWMI-ID:{4464D2C2-9063-4953-AE6F-A0D231EBF3CD}
Attribute 9) msWMI-Name:Imported WMIFilter2
Attribute 10) msWMI-Parm1:This is the description for the filter
Attribute 11) msWMI-Parm2:1;3;10;45;WQL;root\CIMv2;Select * from win32_timezone where bias =-300;

Entry modified successfully.

1 entry modified successfully.

The command has completed successfully

And there you go: you’ve successfully exported and imported WMI filters.

-Mike Stephens