As responsible hosts should you be sending an email to all admin contacts for domains on that sever to:
a) Tell them about the problem
b) Ask them to clean their sites
c) Suggest they change password
d) Check regularly for new attacks
e) Check that no ftp accounts have been added
f) Reassure them about data integrity
Whilst some of the stuff is essentially harmless (broken links to script files) it might not always be. The rest of the stuff is not harmless to have on your
website hosting - it can lead, as we have seen, to being blacklisted by Google, harming your companies reputation (search for my company on Google in russian and you get thousands of porn results!! - lucky i'm not planning on expanding to Russia
). So cleaning
website hostings is essential.
David