logon audit

I have a 2000Server with an event file that I don’t reconize.
118, Security,AUDIT SUCCESS,CHARLEY-UBZX9GT7,Wed Jul17 22:00 2002,538,ANONYMOUS LOGON\NT AUTHORITY,ANONYMOUS,LOGONNT AUTHORITY(0X00X6387ED5)3
The machine has guest and anonymous access denide.
Only 2 people have access.
These anonymous logon success have been goin on for 3 days at this point and I want to find out whats going on. Any suggestions will be welcome.. jim