Did i get hacked?

Tony Meman none at superig.com.br
Fri May 2 13:12:02 PDT 2003


Hi Mario,

well any strange activity in the system should be taken in consideration
so I really think you should audit your system.

You said the reboot ocurred at 0:32am, its a good idea to search for
files modified around that time. You could use the binary of some
trustable system just in case /usr/bin/find got trojaned.

You said you did not find anything in the logs, they could have been
erased, use chkrootkit to verify if there are wtmp/lastlog entries that
may have been erased. Chkrootkit is a pretty nice utility and will be
able to tell you if there're hidden processes running on the system
(comparing output from ps with /proc entries) and search for well-known
rootkits. The tool is not perfect but helps a lot, check it out:

http://www.chkrootkit.org

Good luck,

--
Marcello Azambuja

mario wrote:
 > hello,
 > i have a FreeBSD 4.8-PRERELEASE #0 that i use as a gateway / nat box for
 > my home.
 > It also acts as a dns / mail server to the outside world.
 > I'm using ipf and basically filter for bogus networks on the way in 
and out.
 > I allow everything out keeping state,
 > and allow this in:
 > pass in proto icmp from any to any icmp-type squench group 200
 > pass in proto icmp from any to any icmp-type timex group 200
 > pass in proto icmp from any to any icmp-type paramprob group 200
 > pass in quick proto tcp from any port > 1023 to any port = smtp group 200
 > pass in quick proto udp from any port > 1023 to any port = domain 
group 200
 >
 > on these ports i run qmail and tinydns
 >
 > i was a bit sloppy by leaving these w/out a password
 > figuring they can't login anyway.
 >
 > gtinydns::nnnn:nnnn::0:0:tinydns:/nonexistent:/sbin/nologin
 > gdnslog::nnnn:nnnn::0:0:dns logger:/nonexistent:/sbin/nologin
 > gaxfrdns::nnnn:nnnn::0:0:zone transfer:/nonexistent:/sbin/nologin
 >
 > I've changed this now though i'm still not sure about the implications of
 > this.
 > Also i'm not running tripwire or any other intrusion detection.
 >
 > Here's my problem. When i got up this morning, i noticed that the box
 > rebooted
 > at 0:32 this morning. I have 3 other computers that did not reboot 
leaving me
 > to believe there was no power failure. I looked through all the logs 
seeking
 > clues as to what happened. Hardware failure? It is an old p-75 and 
the hard
 > drive has had issues in udma-2 but has been doing fine for months in pio4
 > mode.
 > I also have a cron job at 0:30 to move the apache logs to a tmp file 
restart
 > apache sleep 5 minutes and then move the tmp file somewhere where 
newsyslog
 > can catch it. According to the logs, apache restarted fine but the 
tmp files
 > never made it anywhere. Again nothing useful in them either.
 >
 > So if this was a hardware failure (harddrive), then any kernel panic
 > statements probably would not make it to the harddrive. So it would be
 > hard to tell. My question is, what if i got hacked? Would there be anyway
 > to find out despite me being totally unprepared for this?
 >
 > That question really messes with my head.
 > Any pointer and/or clue stick treatments would be greatly appreciated.
 >
 > thanx
 >
 > mario;>
 >



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