[Snort-sigs] anyone have more detail other than window size of 55808 to craft a snort rule for this
falciola at ...130...
Thu Jun 12 10:42:38 EDT 2003
FYI - Les Gordon has done a very good writeup on Q and the issues
surrounding NIDS signature development for it:
Information Security Analyst
IBM Managed Security Services
falciola at ...130...
Craig Baltes <craig at ...5...>
06/11/2003 05:08 PM
Please respond to craig
To: "Harris, Michael C." <HarrisMC at ...1375...>
cc: Intrusions <Intrusions at ...473...>, snort-sigs at lists.sourceforge.net
Subject: Re: [Snort-sigs] anyone have more detail other than window size of
55808 to craft a snort rule for this
What they are describing here is basically a "rawIP" trojan and, as CERT
says, this is nothing new. It seems very similar to "Q". They are
calling this a "Third Generation Trojan Horse" but "Q" has been around
for at least 2 years. The mystery trojan that they describe in this
email is actually far less effective and stealthy than a fully
functional "Q" client/server set. "Q" has no common denominator in terms
of packet size or protocol. If this trojan is really limited by having
to be a TCP SYN with a window size of 55808, that really narrows the
window that IDS signature writers need to catch this traffic. If there
is any other common factor to the data then a signature should be
possible, where "Q" is impossible (As far as I can tell) to find via
signature based IDS. Here are some links to "Q" info:
http://lists.jammed.com/pen-test/2002/10/0027.html (My write up on "Q")
http://mixter.void.ru (Mixter is the author of "Q" and has lots of info
about rawIP programming)
Craig Baltes GCIA, CCSE
Senior Information Security Analyst
LURHQ corp. www.lurhq.com
craig at ...5...
On Wed, 2003-06-11 at 16:01, Harris, Michael C. wrote:
> anyone have more detail?
> other than window size of 55808, so we can create a snort rule?
> http://news.ists.dartmouth.edu/todaysnews.html ,
> Title: Is a new Trojan horse at the firewall?
> Source: Government Computer News
> Date Written: June 10, 2003
> Date Collected: June 11, 2003
> Security experts claim to have discovered a yet-unnamed "third
generation Trojan horse" program that appears to be infecting systems on
the Internet. Chris Hovis, director of product marketing for Lancope Inc.,
said that the new Trojan was first identified in May 2003 by a security
analyst for a Defense Department contractor, and that both the FBI and the
CERT Coordination Center at Carnegie Mellon University had been notified
of the threat. The new Trojan listens for specific types of packets that
"are believed to contain encrypted instructions for communicating with
controllers," but the purpose of the Trojan and the extent of the problem
> Is a new Trojan horse at the firewall?
> By William Jackson
> GCN Staff
> IT security professionals have found evidence that a stealthy new Trojan
horse is infecting networks.
> Traffic apparently generated by the as-yet-unnamed malware was first
reported in May by a security analyst for a Defense Department contractor,
said Chris Hovis, director of product marketing for Lancope Inc. of
Atlanta. Lancope announced Monday it had confirmed the behavior of
suspicious packets on its own honeynet and on the network of a large
> The TCP SYN packets are characterized by a window size in the packet
header of 55808. No infected machines have been found, but the Trojan
horse apparently listens for packets with this value, which Hovis said are
believed to contain encrypted instructions for communicating with
> "Based on the activity that we have seen, which looks like probes from
zombie hosts, there are likely infected machines that are looking for that
identifier," Hovis said.
> Because the code of the Trojan horse itself apparently does not include
communication instructions, they are difficult to detect with signature
based antivirus software. Lancope has described it as a third generation
Trojan horse and said the FBI and the CERT Coordination Center at Carnegie
Mellon University had been notified.
> CERT would not comment on the report, but said there is nothing
significantly different about the threat described by Lancope.
> "There is nothing there that hasn't been seen before," said Mary
Lindner, CERT team leader for incident handling. "Every one of these is an
event, but the barometer is not rising."
> Hovis said the Trojan's purpose is unclear, as is how widely it is
distributed. At the current level of activity the suspicious packets could
probe all IP addresses on the Internet every 27 hours.
> System administrators can use tools such as TCPdump, a program that
monitors and filters TCP activity, to find out if machines on their
networks are sources of the telltale probes. Systems can also be monitored
for aberrant behavior, such as unusual amounts of traffic or new ports and
services being opened.
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