Configure Active Directory audit policy

Active Directory audit policy

By default, Active Directory does not automatically log certain security events. You must enable auditing of these events so that domain controllers log them into the Security Windows Event Log channel.

You do this by creating a Group Policy object (GPO) and deploying that GPO to all domain controllers (DCs) in your AD environment. After you activate the GPO, the DCs begin logging these security events into the Security event log.

Then, you install universal forwarders onto the domain controllers and deploy the appropriate Active Directory add-ons into those forwarders. They collect the logs and forward them to the central Splunk App for Microsoft Exchange indexer.

This topic helps you create individual Group Policy objects (GPOs) for both sets of settings. If you want, you can combine both the PowerShell and audit settings into a single GPO. For ease of administration, you should create and deploy these GPOs separately from other GPOs.

Important information on security event auditing and indexing volume

When you enable auditing of the Security Event Log on your domain controllers, the DCs generate a lot of data. These events significantly increase indexing volume and might cause indexing license violations. You might also see decreased performance on your domain controllers based on how much additional data the servers generate.

If you are concerned about the impact that enabling security event auditing might have on your indexing volume, you can tweak policy settings to generate only the data that is important to you. Refer to the table below to learn about which policy settings generate which event types, and how the Splunk App for Microsoft Exchange uses those events to populate its dashboards, reports and lookups.

If you choose to disable certain policy settings in an effort to curb indexing volume, you directly affect how much data gets sent to the Splunk App for Microsoft Exchange. The table below lists what data you do not collect if you decide not to enable a particular policy setting. This is not an all-inclusive list, as the app correlates some lookups across various policy settings, as multiple events often derive a single knowledge object. If you don't enable all of the policy settings, the Splunk App for Microsoft Exchange might display incomplete or incorrect knowledge objects in its dashboards and reports.

Policy setting	Required?	What the Splunk App for Microsoft Exchange uses it for
Audit Account Logon Events	Yes	Administrator Audit dashboards Security->Logon dashboards Security->Reports->New (Computer or Domain) Accounts Session ID-to-User (tSessions) lookup Computer-to-IP Address (tHostinfo) lookup
Audit Account Management	No	Administrator Audit dashboards Change Management dashboards
Audit Logon Events	No	Administrator Audit dashboards Logon and access information
Audit Object Access	No	Administrator Audit dashboards Information on who changed a GPO and when
Audit Policy Change	No	Security->Reports->Group Policy Reports GPO Change Management dashboard
Audit System Events	No	Directory Services replication events

Advanced Audit Policy settings

You might alternatively want to use the Advanced Audit Policy (AAP) configuration settings to control which events your domain controllers send to the Splunk App for Microsoft Exchange. While Splunk supports this method, it is outside the scope of this document to list all available AAP configuration options.

This is because of the number of available AAP configuration options and the fact that those options change with different Windows versions - for example, the options for the Windows Server 2008 family differ vastly from those in the Windows Server 2012 family. Windows Vista and other workstation-class versions of Windows do not support AAP.

If you need more granularity in the types of audit events you want generated, you can review eventtypes.conf (located in the Splunk App for Microsoft Exchange installation at %SPLUNK_HOME%\etc\apps\splunk_app_microsoft_exchange\default) for the event codes that the app looks for. With that information, you can create a GPO that enables AAP and generates audit events for only those specific event codes.

When you enable AAP, Windows disables configurations for standard Audit Policy.

Enable auditing on Windows Server 2008, Server 2008 R2, Server 2012, and Server 2012 R2

Create a new GPO

1. From the Windows Start menu, click Start > Administrative Tools > Group Policy Management.
2. In the left pane, under "Group Policy Management," expand the forest and domain for which you want to set group policy.
3. Right-click Group Policy objects and select New.
4. In the dialog window that opens, enter a unique name for your new GPO that you will remember in the Name field, and select None for the Source Starter GPO field.

Edit the GPO to change audit policy

1. Open the GPO for editing by right-clicking the newly created GPO In the Group Policy Objects window and selecting Edit.
2. In the GPO editor, select Computer Configuration > Policies > Windows Settings > Security Settings > Local Policy > Audit Policy.
3. Enable both Success and Failure auditing of the following policy settings:
   
   • Audit account logon events
   • Audit account management
   • Audit directory service access
   • Audit logon events
   • Audit object access
   • Audit policy change
   • Audit privilege use
   • Audit system events
4. Close the Group Policy Object Editor window to save your changes.

Deploy the GPO

1. In Group Policy Management, in the left pane of the window, right-click on the Domain Controllers item and click Link an existing GPO..."
2. In the window that appears, select the GPO you created.
3. Click OK. The GPMC refreshes to show that your GPO is now linked to the Domain Controllers organizational unit.

Next Step

Configure PowerShell execution policy in Active Directory