HELP. security issue - Urgent - I am being hacked but cant find out how.

From: Andrew Baker (someone@microsoft.com)
Date: 04/03/03 

From: "Andrew Baker" <someone@microsoft.com>
Date: Thu, 03 Apr 2003 13:09:49 GMT

I think someone is hacking my site. Internet download activity has gone
from 100mb to 300 - 1000 mb a day. I have stopped the IIS services but it
is still happening.

It is not an open relay but there are many files named similar to
E00001AE.log in the C:\Program Files\Exchsrvr\MDBDATA at 5mb each. Looking
at the files they are binary files and I cant get any info from them.

There is no client for MS network on the interface card.

please help.

Andrew.
andrewb AT coeng DOT com DOT au