Hi, I want to block bad useragents or spambots surfing to my site. but how or where can i found such bad useragents list.. please help
Good luck with this one. They change their IP address quite often, which makes straight out htaccess deny's rather tough. There is no real solution, as the bots and some useragents will get to your site, regardless of what you do. Is it a forum/blog or a static site?
access logs. When we protect our clients from such attacks, we check access logs and add them to .htaccess or mod_Sec. we also run an updated mod_sec rule set to keep all our clients safe from such attacks.
mod_security contains a large list of bad bots in addition you may surf the web and there are many lists of bad bots to be used in htaccess in addition if you have a dedicated server you may block IP or IP ranges in addition to the other options a root server has