Event-o-Pedia EventID 551 - User initiated logoff [Win 2003 / XP]

	Event Details
	Operating System->Microsoft Windows->Built-in logs->Windows 2000-2003->Security Log->Logon/Logoff->EventID 551 - User initiated logoff [Win 2003 / XP]

EventID 551 - User initiated logoff [Win 2003 / XP]

Indicates that a user that had logged on interactively or by terminal services has started the logoff process.

Note:
This event means that the system started erasing from memory user's primary access token, which contains the user's security information and allows access to objects. After this token is erased, the user cannot access resources such as files or registry keys. When the logoff process (erasure) is completed, a Security 538 message appears in Event Viewer.
If a Security 538 message does not appear shortly after the Security 551 message, a program or service might not be managing its access tokens correctly. Although the user cannot access objects, the program or service might have cached an access token and therefore retained the ability to access objects.

Find more information about this event on ultimatewindowssecurity.com.

Corresponding events on other OS versions:

Windows 2008

EventID 4647 - User initiated logoff

Related events:

Under normal access token system management conditions (see above) this event should be followed by the following event:

EventID 538 - User logoff

Sample:

        Event Type:     Success Audit
        Event Source:   Security
        Event Category: Logon/Logoff
        Event ID:       538
        Date:           10/26/2009
        Time:           07:31:44
        User:           NT AUTHORITY\SYSTEM
        Computer:       DC1
        Description:
        User Logoff:
        User Name:	DC1$
        Domain:		RESEARCH
        Logon ID:		(0x0,0x60FA64)
        Logon Type:	3

Log Type:

Windows Event Log

Uniquely Identified By:

Log Name:

Security

Filtering Field	Equals to Value
OSVersion	Windows 2003 Windows XP
Source	Security
Category	Logon/Logoff
EventId	551

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
Domain	Domain of the account for which logon is requested.	InsertionString2	RESEARCH
User Name	Account name of the user that started the logoff process	InsertionString1	DC1$
Logon ID	ID of the logon session of the user logging off. Useful for tracking other user activity within the same logon session.	InsertionString3	(0x0,0x60FA64)