System settings: Use Certificate Rules on Windows Executables for Software Restriction Policies

Updated: November 15, 2012

Applies To: Windows 7, Windows Server 2003, Windows Server 2008, Windows Server 2008 R2, Windows Vista, Windows XP

This security policy reference topic for the IT professional describes the best practices, location, values, policy management and security considerations for this policy setting.

Reference

This policy setting determines whether digital certificates are processed when software restriction policies are enabled and a user or process attempts to run software with an .exe file name extension. This security setting enables or disables certificate rules (which are a type of software restriction policy). With a software restriction policy, you can create a certificate rule that allows or disallows Microsoft Authenticode®-signed software to run, based on the digital certificate that is associated with the software. For certificate rules to work in software restriction policies, you must enable this security setting.

Possible values

• Enabled

• Disabled

• Not defined

Best practices

1. Set this policy to Enabled. Enabling certificate rules results in software restriction policies checking a certificate revocation list (CRL) to make sure that the software's certificate and signature are valid. When you start signed programs, this setting can decrease system performance. You can disable CRLs by editing the software restriction policies in the desired GPO. In the Trusted Publishers Properties dialog box, clear the Publisher and Timestamp check boxes.

Location

GPO_name\Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options

Default values

The following table lists the actual and effective default values for this policy. Default values are also listed on the policy’s property page.

Operating system version differences

There are no differences in this policy between operating systems beginning with Windows Server 2003.

Policy management

This section describes features and tools that are available to help you manage this policy.

Restart requirement

None. Changes to this policy become effective without a computer restart when they are saved locally or distributed through Group Policy.

Security considerations

This section describes how an attacker might exploit a feature or its configuration, how to implement the countermeasure, and the possible negative consequences of countermeasure implementation.

Vulnerability

Without the use of software restriction policies, users and computers might be exposed to unauthorized software that could include malicious software such as viruses and Trojan horses.

Countermeasure

Enable the System settings: Use Certificate Rules on Windows Executables for Software Restriction Policies setting.

Potential impact

If you enable certificate rules, software restriction policies check a certificate revocation list (CRL) to verify that the software's certificate and signature are valid. This checking process may negatively affect performance when signed programs start. To disable this feature, you can edit the software restriction policies in the appropriate GPO. In the Trusted Publishers Properties dialog box, clear the Publisher and Timestamp check boxes.