- Use of Group Policy to Configure Security
- Auditing of Active Directory Services
- Exam Cram Questions
This chapter is from the book
This chapter is from the book
This chapter is from the book
Auditing of Active Directory Services
Auditing enables you to track actions performed by users across the domain, such as logging on and off or accessing files and folders. When you create and apply an auditing policy, auditable events are recorded in the Security log of the computer where they happen. You can then use Event Viewer to view any computer’s Security log by connecting to the required computer.
New Features of Active Directory Auditing
Windows Server 2008 introduces a new command-line tool, auditpol.exe, as well as subcategories in the Audit Directory Service Access category. In previous versions of Windows Server, a single Directory Service Access category controlled the auditing of all directory service events. In Windows Server 2008, four subcategories of directory service access are available:
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Directory Service Access—Tracks all attempts at accessing AD DS objects whose system access control lists (SACL) have been configured for auditing. This includes deletion of objects.
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Directory Service Changes—Tracks modifications to AD DS objects whose SACLs have been configured for auditing. The following actions are included:
- When an attribute of an object has been modified, the old and new values of the attribute are recorded in the Security log.
- When a new object is created, values of their attributes including new attribute values are recorded in the Security log. This includes objects moved from another domain.
- When objects are moved from one container to another, the distinguished names of the old and new locations are recorded in the Security log.
- When objects are undeleted, the location in which they are placed is recorded in the Security log. Any added, modified, or deleted attributes are recorded also.
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Directory Service Replication—Tracks the beginning and end of the synchronization of a replica of an Active Directory naming context.
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Detailed Directory Service Replication—Tracks additional AD DS replication events, including the establishment, removal, or modification of an Active Directory replica source naming context, replication of attributes for an AD DS object, or removal of a lingering object from a replica.
The auditpol.exe tool enables you to configure auditing from the command line. You must use this tool to enable the auditing of the new directory service access subcategories outlined here. We discuss this tool later in this section.
Use of GPOs to Configure Auditing
Group Policy enables you to configure success or failure for several types of actions. In other words, you can choose to record successful actions, failed attempts at performing these actions, or both. For example, if you are concerned about intruders who might be attempting to access your network, you can log failed logon events. You can also track successful logon events, which is useful if the intruders succeed in accessing your network.
You can use Group Policy to enable auditing at domain controllers, member servers, and client computers. Be aware that all auditing takes place only at the local computer where the events take place, and that these events are recorded on that computer’s Security log. To enable auditing on all domain controllers, configure the auditing settings in the Default Domain Controllers Policy GPO; to enable auditing on other domain computers, configure the auditing settings in the Default Domain Policy GPO or in another GPO as required.
Available Auditing Categories
Windows Server 2008 enables you to audit the following types of events:
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Account logon—Logon or logoff by a domain user account at a domain controller. You should track both success and failure.
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Account management—Creation, modification, or deletion of computer, user, or group accounts. Also included are enabling and disabling of accounts and changing or resetting of passwords. You should track both success and failure.
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Directory service access—Access to an AD DS object as specified by the object’s SACL. This category includes the four subcategories mentioned earlier in this section; enabling directory service access from the Group Policy Management Editor enables all four subcategories. Enable this category for failures. (If you record success, a large number of events will be logged.)
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Logon events—Logon or logoff by a user at a member server or client computer. You should track both success and failure. (Success logging can record an unauthorized access that succeeded.)
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Object access—Access by a user to an object such as a file, folder, or printer. You need to configure auditing in each object’s SACL to track access to that object. Track success and failure to access important resources on your network.
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Policy change—Modification of policies, including user rights assignment, trust, and audit policies. This category is not normally needed unless unusual events are occurring.
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Privilege use—Use of a user right, such as changing the system time. Track failure events for this category.
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Process tracking—Actions performed by an application. This category is primarily for application developers and does not need to be enabled in most cases.
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System events—Events taking place on a computer, such as an improper shutdown or a disk with little free space remaining. Track success and failure events.
Configuring Auditing
To configure auditing policies, access the Group Policy Management Editor focused on the desired GPO. For auditing actions on domain controllers, this will generally be the Default Domain Controllers Policy GPO. Navigate to the Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\Audit Policy node and click this node to display the available policies in the Details pane.
To enable auditing of any of these event types, right-click it and choose Properties. On the Properties dialog box shown in Figure 7.9, select Define These Policy Settings, select Success and/or Failure as required, and then click OK. New to Windows Server 2008, the Explain tab of each policy’s Properties dialog box provides more information on what the setting does.
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Figure 7.9 Enabling auditing of object access.
To track object access or directory service access, you must configure the SACL for each required object. In Windows Explorer, right-click the required file, folder, or printer, and choose Properties. On the Properties dialog box, click Advanced to open the Advanced Security Settings dialog box, and then select the Auditing tab. To add users or groups to this tab, click Edit and then click Add. Type the required users or groups in the Select User, Computer, or Group dialog box, and then click OK. On the Auditing Entry dialog box that appears (see Figure 7.10), select the types of actions you want to track, and then click OK. The completed auditing entries appear in the Advanced Security Settings dialog box, as shown in Figure 7.11. Click OK twice to close these dialog boxes.
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Figure 7.10 Configuring the SACL for an AD DS object.
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Figure 7.11 The Advanced Security Settings dialog box displays information on the types of object auditing actions that have been specified.
After you have configured object access auditing, attempts to access audited objects appear in the Security log, which you can view from Event Viewer either in Server Manager, as shown in Figure 7.12, or in its own snap-in from the Administrative Tools folder. For more information on any audited event, right-click the event and choose Event Properties.
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Figure 7.12 Event Viewer displays failed attempts at accessing an object with a lock icon.
Use of Auditpol.exe to Configure Auditing
The Auditpol.exe tool performs audit policy configuration actions from the command line. This is the only tool you can use to configure auditing on a Server Core computer or to configure directory service auditing subcategories.
To use this tool, type the following at a command line:
Auditpol command [<sub-command><options>]
Table 7.1 describes the available commands, and Table 7.2 describes several of the more important subcommands and options that you should be aware of.
Table 7.1. Auditpol Commands
|
Command |
Meaning |
|
/get |
Displays the current auditing policy |
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/set |
Sets the audit policy |
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/list |
Displays audit policy categories and subcategories, or lists users for whom a per-user audit policy is defined |
|
/backup |
Saves the audit policy to a specified file |
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/restore |
Retrieves the audit policy from a specified file |
|
/clear |
Clears the audit policy |
|
/remove |
Removes per-user audit policy settings and disables system audit policy settings |
Table 7.2. Auditpol Subcommands and Options
|
Option |
Meaning |
|
/user:<username> |
Specifies the security principal for a per-user audit. Specify the username by security identifier (SID) or by name. Requires either the /category or /subcategory subcommand when used with the /set command. |
|
/category:<name> |
One or more auditing categories separated by | and specified by name or Globally Unique Identifier (GUID). |
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/subcategory:<name> |
One or more auditing subcategories separated by | and specified by name or GUID. |
|
/success:enable |
Enables success auditing when using the /set command. |
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/success:disable |
Disables success auditing when using the /set command. |
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/failure:enable |
Enables failure auditing when using the /set command. |
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/failure:disable |
Disables failure auditing when using the /set command. |
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/file |
Specifies the file to which an audit policy is to be backed up, or from which an audit policy is to be restored. |
For example, to configure auditing for directory service changes, you type the following:
Auditpol /set /subcategory:"directory service changes" /success:enable
Additional subcommands and options are available with most of the auditpol commands discussed here. For information on the available subcommands and options available for a specified command, type auditpol /command /?.