My first suggestion to you is if you want to figure out what was done to
hack the box, pull the drive and save it.
To get the box up and going again, reinstall (I would suggest this no
matter what) on a new drive (so you can keep the old info to diagnose
the hack) and restore data from backups.
Use the newest versions of Gentoo, Apache, SSH, PHP and Squirl Mail.
Then get your admin back in. Use keys for your ssh logins, make sure
every process is running under a setup acct for it, and do a full suid
audit.
That's a start, I have little experience in diagnosing root kits, but
that's where you begin.
-Conlan
-----Original Message-----
From: Nicholson, Dale [mailto:DNicholson@APACMail.com]
Sent: Wednesday, October 20, 2004 12:52 PM
To: security-basics@securityfocus.com
Subject: Linux hacked
First let me say I'm a security novice. Please bear with me.
My home linux (gentoo) machine was hacked last Thursday. Installed
active
on the box was ssh, apache, php 5, and a squirl mail. Iptables was set
up
for a firewall. The box was set up as a web server with a number of
websites and about 35 email accounts (separate passwords for the mail
than
the user accounts on the box).
I'm guessing it was some sort of script kiddie if the names taking
credit
for the hack in the hidden folders I found are any indication. I did
some
research on the person taking credit and found all kinds of information
on
him, he's an 18yr old kid in Germany. I doubt he is very knowledgeable
or
he would not have alerted me to the intrusion by somehow locking out all
accounts from the machine.
To get in I have to boot from cd and chroot in. Everything I've tried
has
been unsuccessful in getting root back.
I found a hidden directory /var/tmp/.tmp that has a bunch of directories
under it with names like +_01_+++++++HaXorEd by ... and
+_05_++++++++++Movies++++++....
I unplugged the machine from the internet shortly after the hack and can
find no evidence of any uploads. I do see that the person somehow was
able
to break root. I was only able to find the hidden directories because
the
person forgot to clean up root's history file where I found the command
used
to create the them. The box was set up to not allow remote login of
root
via ssh but you could su in once logged in as one of three users.
I'm a novice at security and had been depending on my system admin to
keep
the box up to date. He tells me he's been doing an emerge world every
week
but I don't know how to tell.
Can someone help me with where to get a listing of everything I have
installed and the versions? I can't remember if the kernel is a 2.4 or
2.6
but I think it's 2.6. Plus I know there have been problems with ssh in
the
past but I don't know which versions have problems and I'm not sure how
to
find out what version I'm running. I'm kind of stuck as my sys-admin
normally handles these things but he cannot ssh in to the box without me
first fixing the problem since he lives 13 hours from me (the box is in
my
basement).
Also, I need something that can detect root kits etc. on linux. I've
heard
knoppix mentioned as having good tools on this list for an example, but
I
wouldn't know what tools to use for this particular case.
This is what I tried so far:
I logged in using a boot CD, mounted the hard disks, chrooted in,
blanked
out the root password in the /etc/shadow file, changed the root
password,
rebooted and tried to log in normally. This did not work. I also
checked
that the correct users were in both /etc/passwd and /etc/shadow.
Note that both the email and websites were still working despite not
being
able to log in, although not now of course since I unplugged the
ethernet
cable.
Any comments/assistance will be greatly appreciated.
