i working in hosting company. A few website at our server hacked last n谋gth. Attack was not com谋ng from ftp server. 7-8 web site's index.htm files changed on same time 00:43:34. I th谋nk they use an program for automate process. What k谋nd a attack?

And i look for resource about server security

you need to start with the basics. you need to tell us what the operating system and the version being run as well as the webserver being used and its version and anyother technologies which are avaible on your server as it could be any of these which has exposed a vulnerability.

You shouldn't really be hosting if you don't understand server security.

waooo looks bad

get a zone alarm pro and you will know. go to www.9down.com and get it