[ulf]

Even better is to additionally setup a fake SSHd at port 22, so that port scanners do not even bother keeping on looking for the port and instead use what they suspect to be working

[mfontani]

I use https://code.google.com/p/kippo/ as a ssh honeypot, and https://github.com/mfontani/kippo-stats to display stats about it (number of attempts, successful logins, most usernames tried, most passwords tried for "root").

The data is quite interesting.

Here's a snapshot of where most "attacks" to my honeypot originate from (the more, the brighter): http://darkpan.com/files/latlong255.png

[nodata]

kippo's code is going to be less audited than openssh's. do you run kippo as root? is the risk of running kippo worth the stats?

[mfontani]

I run it as a dedicated user, on a high port. Port 22 of the router is merely forwarded to the internal high port I use. Sure, I could chroot the thing as well.

[gbrindisi]

kippo can't be executed as root.

[dmm]

How does it open a server on a port <1024 without privileged access?

[rosser]

It probably doesn't.

  # accept traffic to the normal ssh port
  iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT
  # accept traffic on the port kippo is listening on
  iptables -A INPUT -i eth0 -p tcp --dport 2222 -j ACCEPT
  # direct traffic inbound on port 22 to port 2222
  iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 22 -j REDIRECT --to-port 2222

Make sure also to add an ACCEPT rule for traffic to whatever port sshd is actually bound to.

[cft]

http://www.faqs.org/docs/iptables/traversingoftables.html Table nat is traversed <b>before</b> filter table. Therefore, the rule iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT is unnecessary.

[dmm]

That's fine so long as you trust all of the users on your system. Otherwise they could potentially get something running on port 22. Which, so long as you aren't actually sending auth info to 22, probably isn't a big deal.

[epochwolf]

You use iptables to route port 22 on the external interface to a high port on localhost

[dedward]

As interesting and fun as honeypots are - unless it's your own gig, or the data from the honeypot fits into a larger security plan, it's just adding one more thing to manage. Move the port, run denyhosts, and in general just have access firewalled off to begin with.