Hi

This is a strange problem as it is on a machine behind a DMZ and "chained" 
FIREWALL (CentOS).

I have a "/etc/hosts.deny" that has following line:

  ALL : ALL : spawn ( /usr/sbin/safe_finger -l @%h | /usr/bin/Mail -s 
"THE_HOSTNAME\: Host denied\: %d from %c(%u)-%h" [email protected]) &

which delivers following email every random minutes:

  THE_HOSTNAME: Host denied: sshd from 43.255.189.72(unknown)-43.255.189.72  

Normally it would not bother me, but the fact this machine is behind a DMZ and 
a FIREWALL makes this "interesting".
I, too, know the machine (and network) in question are quite wellknown ;-)

Now the thing is that "hosts.deny" sits before I can see the traffic with 
tcpdump/ngrep/iptraf, so this makes it a little harder to debug.

This is what I know:

 - only I have shell access (passwd file is full of /bin/false and 
/bin/nologin) and it's ONLY via keys.
 - rkhunter, chkrootkit and so on have no warnings
 - the machines sendmail has clamav attached
 - external firewall disallows access to that machine (only from internal 
network)
 - external firewall blocks the entire network of 43.0.0.0/24
 - the machine is my Samba Server
 - the machine is fully up to date and rebooted
 - it is my webdevelopment server for some domains
 - it has some internal webserver tasks
 - I have turned off ALL internal devices that could be hacked (nas drives, 
wifi, etc)
 - the messages come up even if NO workstation is on
 - external ssh is firewalled 


I have tried all the standard utils (tcpump,lsof,fuser,netstat and so on) but 
this one has me baffled.
Any ideas anyone?


Jobst





-- 
Howard's conjecture: The total dinner check of a party eating dutch will never 
equal the total of what each diner admits to having eaten.

  | |0| |   Jobst Schmalenbach, [email protected], General Manager
  | | |0|   Barrett Consulting Group P/L & The Meditation Room P/L
  |0|0|0|   +61 3 9532 7677, POBox 277, Caulfield South, 3162, Australia
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