On Mon, Jul 21, 2008 at 04:43:11PM -0400, Bo Lynch wrote:
just wanted to get some feedback from the community. Over the last few days I have noticed my web server and email box have attempted to ssh'd to using weird names like admin,appuser,nobody,etc.... None of these are valid users. I know that I can block sshd all together with iptables but that will not work for us. I did a little research on google and found programs like sshguard and sshdfilter. Just wanted to know if anyone had any experience with anything like these programs or have any other advice. I really appreciate it.
If you have a web server on the same system, you can use php and tcp wrappers to restrict ssh inbound traffic to known systems, plus give you a back-door key to permit yourself access from arbitrary systems on the internet.
http://wiki.xdroop.com/space/Linux/Limited+SSH+Access