unknown failure audits with logon process advapi

From: mcwe_admin (mcweadmin_at_discussions.microsoft.com)
Date: 05/06/05


Date: Fri, 6 May 2005 09:42:02 -0700

I get many of the following failure audits in the security logs:

Event Type: Failure Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 529
Date: 5/6/2005
Time: 8:04:53 AM
User: NT AUTHORITY\SYSTEM
Computer: DELL_SERVER
Description:
Logon Failure:
         Reason: Unknown user name or bad password
         User
Name: ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ
         Domain: DELL_SERVER
         Logon Type: 2
         Logon Process: Advapi
         Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
         Workstation Name: DELL_SERVER

I am not sure if this is a virus?

Thanks for any reply.