Security breach

"John Gordon Ollason" <john-vtmTuu8IIOWEBxnelpYi71pr/1R2p/[email protected]> Mon, 04 Jul 2011 10:14:55 +0100

Newsgroups	gmane.user-groups.linux.scottish
Message-ID	<[email protected]>

Greetings,

I received e-mail from the ISP that hosts my websites that my shell  
account had been used in a security breach. I have had a superificial  
check of my files, and can't find anything altered. What checks ought I to  
do to insure the integrity of my files? And what harm could my websites do  
if something nasty has been left behind?

Thanks for any advice.

John O.