Full Disclosure mailing list archives

Re: Show me the Virrii!


From: "Exibar" <exibar () thelair com>
Date: Wed, 7 Jan 2004 10:11:47 -0500

Although I agree with your other points, I have this comment:

Why do you ultimately blame Windows/DOS for the virus problem?  This is
simply not true.  Are there not SQL worms?  Was it not a SQL worm that was
the fastest to spread in history?  Are there not many Linux worms and
viruses, and more being written each day?  Are there not viruses and/or
worms that exploit Cisco products?  Hell there are even worms that exploit
FTP and IRC!  I can go on.

   It is not Windows that is the problem.  It is the people that write the
damned things that is the problem.  Ok, perhaps it's the lack of laws that
will make a programmer think twice about becoming a Vx'r.

   If Linux had the marketshare that Windows does right now, and it just
might one day it's hard to compete with free, and the majority of viruses
are being written for Linux, would you then blame Linux as the cause of the
problem?

  Saying Windows is to blame for the mess that we're in is like saying the
gun is what causes a murder and not the person that pulled the trigger.

  Exibar

----- Original Message ----- 
From: <John.Airey () rnib org uk>
To: <full-disclosure () lists netsys com>
Sent: Wednesday, January 07, 2004 5:15 AM
Subject: RE: [Full-disclosure] Show me the Virrii!


-----Original Message-----
Date: Mon, 05 Jan 2004 09:09:57 -1000
From: Jason Coombs <jasonc () science org>
Reply-To: jasonc () science org
Organization: SCIENCE.ORG
To: Richard Maudsley <r_i_c_h () btopenworld com>
CC: full-disclosure () lists netsys com
Subject: Re: [Full-disclosure] Show me the Virrii!

Richard Maudsley wrote:
I recently finished a stable version of my little
Virus-Scanner, LMS (
http://www.mindblock.org/lms ).
It currently detects 19 viruses. I need it to detect hundreds.

How do big Anti-Virus companies get their hands on new viruses, and
how
can I?

Antivirus software is one of the biggest frauds going in the software
industry. You really don't want to go there. Consider
something useful
instead:

(from http://www.windevnet.com)

Antivirus Software Turned Upside Down
by Jason Coombs (jasonc () science org)

Antivirus software exists because viral code and malware
exist. Malware
signature databases coupled with antivirus software provide what I'll
call "matter of fact, after the fact" security. It is a
matter of fact
that bytes matching an a/v vendor's malware signature must have
malicious potential resembling a known virus, worm, Trojan, or other
code analyzed in the past by the a/v software vendor and labeled as
harmful. While false positives do occur in practice, a virus scanner
wouldn't be useful if it constantly failed to distinguish between
malware and user data or desireable code. Therefore, a/v software
becomes the best proof, in practice, that particular bits are
hostile.
No jury is likely to reject forensic testimony designed to
establish the

presence of malware after seeing a forensic examiner employ a trusted
brand-name a/v scanner to detect a virus or Trojan on a hard drive or
other storage device. A commercial virus scanner makes a terrific
exhibit in front of a jury. As a result, there is a distinct
possibility

that civilian security researchers may help to convict hackers (and
other civilian security researchers) of computer crimes
simply by adding

definitions to a virus signature database. Law enforcement
simply lack
the resources necessary to assemble definitive lists of
criminally-malicious bits, so we end up with an interesting, and
uncomfortable, overlap between private sector business
decisions and law

enforcement investigations.

Antivirus software vendors make no effort to conceal the fact
that they
are in the business of selling virus signature updates. They sell
content more than software, and it is content updates that
drive their
profits. Updates to virus definitions occur after the fact,
so everyone
is always out-of-date and must keep paying in order to feel
protected.
This makes for a good business, but it doesn't make for very good
security. In fact, it's completely backwards. Think about it for a
moment, why should anyone go through the expense and the trouble of
keeping a running list of all bad code ever encountered? We can prove
that something is good just as easily as we can prove that
something is
bad, but publishing a list of all known good software
wouldn't be very
profitable. Few people would ever have a need for the entire
database.
Most people would have no need for updates unless they planned to
install more software. Restricting the execution of code by a
CPU to a
small list of known good programs that the owner of the
computer chooses

to trust would basically kill the antivirus industry. Such a
deny-first
security policy would give computer owners the kind of control over
their boxes that the introduction of automobile ignition keys gave to
early motorists. The fact is that today's computers are still
designed
to accomodate arbitrary drivers as though the absence of
security is a
feature demanded by the marketplace.

This brings to mind the purportedly-true story of the
evolution of the
automobile seatbelt. You've probably heard that consumers resented
seatbelts initially, and manufacturers didn't want to install them,
because they gave the impression that there was danger involved in
driving a car. Compared to the seatbeltless horse or bicycle,
a car with

a seatbelt looked scary, and car manufacturers weren't in the fear
business, they sold convenience and other delightful things. I'm not
going to take the time to track down a definitive answer to
the question

of the authenticity of this historical tale, if it isn't true then
perhaps it should have been. Rhetoric is always better when
it's mostly
true. The point is that computing can't continue without
seatbelts. We
simply cannot let our CPUs continue to execute whatever
happens to come
along each day. If you've ever tried to assemble a list of
the processes

normally executed by one of your Windows boxes, so that you might be
able to spot a suspicious process that wasn't there before, you've
probably realized that a malicious process can come and go
faster than
the Windows Task Manager will refresh. And Task Manager
doesn't bother
to keep a record of past program executions, so you'll only spot a
suspicious process in this way if it happens to be long-lived
or if you
audit process execution at just the right time. Putting aside for a
moment the obvious need for better low-level hardware-based controls
over code execution, is there really any reason for Windows to allow
programs to execute without first requiring the end-user or an
administrator to authorize them in advance using a simple software
control?

If we add even the simplest software seatbelt to the boxes we drive
every day, we can turn antivirus software upside down, replacing it
instead with anti-software software. Not unlike the
anti-driver purpose
served by automobile ignition keys, or the anti-death purpose
served by
seatbelts, we must redesign our infosec safety precautions around the
idea that the bad things that can happen are worse than the
protections
we must have to guard against them. Nobody would accept an
out-of-date
list of ways in which one can die in an automobile in lieu of a
seatbelt, so why do we accept that an out-of-date list of bad
code is a
viable way to protect ourselves while we drive a computer?

To complete what turned out to be a three-part-series on using hash
algorithms for code authentication and containment, below I offer a
working prototype of a software seatbelt for Windows. The last two
articles in this newsletter laid the foundation for forensic
hash sets
produced using the MD5 or SHA-1 hash algorithms and comprehensive,
full-file hash digests as a replacement for the Microsoft
plan to some
day make digital signatures work perfectly. Software vendors should
communicate hash sets to users, and users should assemble and
periodically verify hash sets of code modules installed on Windows
boxes. But we also need runtime verification of hashes against our
trusted hash sets. That's what the prototype below is designed to
accomplish, albeit very crudely. The best way for runtime hash
verification to occur is doubtless with the assistance of hardware
enhancements to CPU and motherboard architecture. No add-on,
after-the-fact technique to inject hash verification (or antivirus
scanning, for that matter) into Windows will ever be as good
as a simple

kernel modification. Still, the code shown below isn't a
complete waste
of time. I've been using a precursor to this code for a
while, without
the hash verification feature, and feel that it gives a
valuable log of
executable modules that are invoked on a box, if nothing
else. By adding

hash code profiling and verification based on the work shown
in the last

two newsletter articles this code begins to look more promising. At
least as a source of ideas and code.

[snip code example]

I think the example of seatbelts is a poor one (and so is the use of the
word evolution, but then again, nearly everyone else abuses that word
without having a clue what they are talking about). it's especially poor
considering that few (if any) Americans actually use a seatbelt,
preferring
instead to trust their lives to a controlled explosion going off in their
face.

A better example would be prisons. We put in prison those that we believe
to
be guilty of criminal acts. Most of the time we get it right.

To imprison everyone, and then only free the ones that you trust would not
be viable (although it should be noted that it appears that America is
trying just this). Taking into account the accuracy of such decisions, you
would most probably free more criminals than were imprisoned before.

Indeed, the current situation is not good. Anti-virus companies are
basically making money out of criminal acts. But so are private prison
companies, the courts, lawyers etc. What makes the anti-virus industry
unique is that each company shares information with all its competitors. I
can't think of another industry that does this.

We have reached a stage now where anti-virus products alone do not protect
our data. Thousands of machines can be infected with a virus before an
update is released. However, reversing this and only running "trusted"
code
would give us far more difficulties. What if a malicious program gets
"trusted". How can it be "untrusted" again?

We have already seen cases of security certificates being issued to
someone
who supposedly worked at Microsoft. So if you have an "approval" process,
you need an "unapproval" process, which puts us back where we started! Who
will control the "approval/unapproval" process, and how could they escape
anti-trust laws? The only companies I can think of with the expertise to
do
this collaboratively are the same anti-virus companies you criticise.
They'd
probably even charge *more* for the service.

Your proposal sounds very much like palladium, which carries the same
fatal
design flaws.

As for your first point about anti-virus databases being tampered with to
force a wrongful prosecution, do you have any evidence of this? Such
antics
in the UK would be a criminal act, known as "attempting to pervert the
course of justice" which carries a prison sentence. Fabricating evidence
is
a serious crime in many other countries too.

In fact, all a defence would have to do is show that other anti-virus
vendors don't detect the code as a virus. More evidence in the defendant's
favour will sway any jury. Anti-virus companies currently accept
submissions
from software companies whose products generate a false positive, so I'm
at
a loss to see how this could ever be successful.

A better proposal would have been to disconnect the Internet. Without it,
we'd never have such rapid virus propagation, but of course then we
wouldn't
be having this discussion.

Hopefully we all realise that it is the fundamental design of Windows/DOS
that is mostly responsible for the mess we are in, but most of the world
is
hooked on it now. Unless that situation changes, we are pretty much stuck
on
the AV-update treadmill.

-
John Airey, BSc (Jt Hons), CNA, RHCE
Internet systems support officer, ITCSD, Royal National Institute of the
Blind,
Bakewell Road, Peterborough PE2 6XU,
Tel.: +44 (0) 1733 375299 Fax: +44 (0) 1733 370848 John.Airey () rnib org uk

Even if you win the rat race, that will still only make you a rat.

-
DISCLAIMER:

NOTICE: The information contained in this email and any attachments is
confidential and may be privileged. If you are not the intended
recipient you should not use, disclose, distribute or copy any of the
content of it or of any attachment; you are requested to notify the
sender immediately of your receipt of the email and then to delete it
and any attachments from your system.

RNIB endeavours to ensure that emails and any attachments generated by
its staff are free from viruses or other contaminants. However, it
cannot accept any responsibility for any  such which are transmitted.
We therefore recommend you scan all attachments.

Please note that the statements and views expressed in this email and
any attachments are those of the author and do not necessarily represent
those of RNIB.

RNIB Registered Charity Number: 226227

Website: http://www.rnib.org.uk

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html



_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.netsys.com/full-disclosure-charter.html


Current thread: