Event-o-Pedia EventID 517 - The audit log was cleared

	Event Details
	Operating System->Microsoft Windows->Built-in logs->Windows 2000-2003->Security Log->System->EventID 517 - The audit log was cleared

EventID 517 - The audit log was cleared

This event record indicates that the audit log has been cleared. This event is always recorded, regardless of the audit policy. It is recorded even if auditing is turned off.

Note:
The audit log should be saved in a file before deleting. The practice of always saving copies of audit logs is good for catching fraudulent users. A fraudulent user with sufficient privileges can delete the audit log as a way of erasing evidence of tampering with the computer systems and files. Lack of a backed-up audit log will help trace an unauthorized user. Once deleted, an audit log is lost unless a copy was made and saved before deleting.

Primary User Name identifies the system, and Client user name identifies the user who cleared the log.

Find more information about this event on ultimatewindowssecurity.com.

Corresponding events on other OS versions:

Windows 2008

EventID 1102 - The audit log was cleared

Sample:

        Event Type:     Success Audit
        Event Source:   Security
        Event Category: System Event
        Event ID:       517
        Date:           10/26/2009
        Time:           07:31:38
        User:           NT AUTHORITY\SYSTEM
        Computer:       DC1
        Description:
        The audit log was cleared

        Primary User Name:	SYSTEM
        Primary Domain:	NT AUTHORITY
        Primary Logon ID:	(0x0,0x3E7)
        Client User Name:	Alebovsky
        Client Domain:	RESEARCH
        Client Logon ID:	(0x0,0x59DF36)

Log Type:

Windows Event Log

Uniquely Identified By:

Log Name:

Security

Filtering Field	Equals to Value
OSVersion	Windows 2000 Windows XP Windows 2003
Category	System
Source	Security
EventId	517

Field Matching

Field	Description	Stored in	Sample Value
DateTime	Date/Time of event origination in GMT format.	DateTime	10.10.2000 19:00:00
Source	Name of an Application or System Service originating the event.	Source	Security
Type	Warning, Information, Error, Success, Failure, etc.	Type	Success
User	Domain\Account name of user/service/computer initiating event.	User	RESEARCH\Alebovsky
Computer	Name of server workstation where event was logged.	Computer	DC1
EventID	Numerical ID of event. Unique within one Event Source.	EventId	576
Description	The entire unparsed event message.	Description	Special privileges assigned to new logon.
Log Name	The name of the event log (e.g. Application, Security, System, etc.)	LogName	Security
Category	A name for a subclass of events within the same Event Source.	Category	Logon/Logoff
Primary User Name	The username of the system where the log was cleared (always SYSTEM)	InsertionString1	SYSTEM
Primary Domain	Since this takes place within the system, domain is NT Authority	InsertionString2	NT AUTHORITY
Primary Logon ID	ID of the logon session of the computer where the log was cleared	InsertionString3	(0x0,0x3E7)
Client User Name	The user that cleared the audit log	InsertionString4	Alebovsky
Client Domain	The domain of the user that cleared the log	InsertionString5	RESEARCH
Client Logon ID	ID if the logon session of the user that cleared the log. Useful for finding other events indicating the same user activity during the same logon session.	InsertionString6	(0x0,0x59DF36)