This subcategory reports changes in audit policy including SACL changes. Events for this subcategory include: - 4715: The audit policy (SACL) on an object was changed. - 4719: System audit policy was changed. - 4902: The Per-user audit policy table was created. - 4904: An attempt was made to register a security event source. - 4905: An attempt was made to unregister a security event source. - 4906: The CrashOnAuditFail value has changed. - 4907: Auditing settings on object were changed. - 4908: Special Groups Logon table modified. - 4912: Per User Audit Policy was changed. Refer to the Microsoft Knowledgebase article "Description of security events in Windows Vista and in Windows Server 2008" for the most recent information about this setting: http://support.microsoft.com/kb/947226. Vulnerability: If audit settings are not configured, it can be difficult or impossible to determine what occurred during a security incident. However, if audit settings are configured so that events are generated for all activities the Security log will be filled with data and hard to use. Also, you can use a large amount of data storage as well as adversely affect overall computer performance if you configure audit settings for a large number of objects. If failure auditing is used and the Audit: Shut down system immediately if unable to log security audits setting in the Security Options section of Group Policy is enabled, an attacker could generate millions of failure events such as logon failures in order to fill the Security log and force the computer to shut down, creating a Denial of Service. If security logs are allowed to be overwritten, an attacker can overwrite part or all of their activity by generating large numbers of events so that the evidence of their intrusion is overwritten. Counter Measure: Enable Audit policy settings that support the organizational security policy for all the computers in your organization. Identify the components that you need for an audit policy that enables your organization to hold users accountable for their actions while using organizational resources and enables IT departments to detect unauthorized activity efficiently and then track those events in log files. Potential Impact: If no audit settings are configured, or if audit settings are too lax on the computers in your organization, security incidents might not be detected or not enough evidence will be available for network forensic analysis after security incidents occur. However, if audit settings are too severe, critically important entries in the Security log may be obscured by all of the meaningless entries and computer performance and the available amount of data storage may be seriously affected. Companies that operate in certain regulated industries may have legal obligations to log certain events or activities. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\Audit Policies\Policy Change\Audit Policy: Policy Change: Audit Policy Change (2) REG: NO INFO [audit_none/audit_success/audit_failure/audit_success_failure] (1) GPO: Computer Configuration\\Windows Settings\\Security Settings\\Advanced Audit Policy Configuration\\Audit Policies\\Policy Change\\Audit Policy: Policy Change: Audit Policy Change (2) REG: NO INFO oval:org.secpod.oval:def:40281 SCAP Repo OVAL Definition 2017-04-25