can you answer these questions?

[Richard Cook <richard_cook@xtra.co.nz>]

Hi there,

I am interested in installing debian again after not using it for a while 
because I had problems with trying to use it.  I read on your news pages 
about the break-in and this is a small concern to me as this could 
potentially be used by anyone that wants to access the system and since my 
knowledge of linux/debian is not that great I would like to know some 
things that I can do in order to close off any ports etc to prevent this 
happening.

Can you provide any help in regards to this and trying to understand 
how/what methods this person(s) used is not all that clear to me appart 
from he used a pw sniffer but how did they sniff the pwds to begin with - 
that is why I would appreciate any info in regards to what I can lock down 
to prevent something like this happening or if there is monitoring software 
that I can install that will at least inform me of something like this 
happening.

Thanks in advance to your reply to this email.

Richard