RE: [fw-wiz] How to Save The World (was: Antivirus vendor conspiracy theories)
From: Ben Nagy (ben_at_iagu.net)
To: "'Devdas Bhagat'" <firstname.lastname@example.org>, <email@example.com> Date: Mon, 6 Dec 2004 10:09:56 +0100
> -----Original Message-----
> > A firewall, for example, does a generally good job of
> allowing or declining
> > traffic at layer 3/4, but a generally crappy job at looking
> at layer 7.[...]
> A packet filter is one component of, but not a complete firewall
> solution by any means. There are these things termed as
> proxies ;), and
> then you have host based security as well to add to the mix.
I'm well aware of proxies, worked with them almost exclusively for a number
of years, and I am _explicitly_ including them in "things that do a crappy
job of looking at layer 7". The ones that are fast enough to not get thrown
out do almost nothing beyond actually letting the protocol work. The ones
that attempt to provide any real security need to be too generic to have any
real effect, and/or are too slow to use. I blame the protocols more than the
proxies, but that's still how I see it.
I'm all for building architectures which use proxies where possible, I just
wouldn't realistically expect them to save anybody's bacon from many current
> > Spyware, adware and all those tasty browser malwares work
> by exploiting the
> > security identity of IE, making it impossible for an AV to
> tell that the
> > functions are not what was intended.
> And I would say that preventing spyware and spamware from operating is
> not in the purview of the antivirus software.
That was, in fact, exactly what I said. :)
> Wouldn't it be far easier for the A/V vendors to just ship an
> alternative browser, and recommend its installation and usage
> instead of
> the malware spreading vectors?
No. That would be the commercial equivalent of stuffing hundreds of
marshmellows up their nostrils and hoping to burp cotton candy.
> > [Paul]
> > > The market won't accept better mechanisms, just like better
> > > firewalls are disdained in favor of IDS, which is also a reactive
> > > technology.
> Actually, IMHO, what the market isn't accepting is a
> separation between
> the active and passive components of a defense system.
> What the market desires is a feature in the passive components which
> allows them to react to malicious events going past the active
> components and prevent the events from occuring, in essence converting
> the passive components to active ones.
I'm not sure that's the case. However, a whole slew of vendors _hope_ it is.
I call this the "firewIDS", the unholy crossbreed of a firewall and IDS.
It's a very popular concept these days, especially amongst IDS vendors who
recently suffered the "emperor's new clothes" effect, and are desperately
looking for ways to re-use that intellectual property.
There are two massive flaws with that approach, whether you are talking
about implementing it at the host or network level.
1. Nobody seemed to be able to make an IDS that was both dumb enough to be
commercially successful and accurate enough to be useful. I have yet to find
a _single_ IDS expert that would be comfortable letting their IDS make
firewall rule decisions. This does not fill me with confidence for software
or appliances that are essentially doing exactly that.
2. It's fundamentally reactive. If you have no signature, you have no extra
protection and have to wait until the vendor releases a signature (at which
time you remain safe for about an hour until the variants start popping up).
IMO all the guys doing "behaviour blocking", "deep inspection" blah blah
blah are onto a much better bet. Signatures are basically sucky.
There are other flaws too, but I risk setting myself off on a rant.
> An IDS sitting behind a restrictive proxy firewall watching out for
> malicious events and restricting those from propagating is a
> good idea
> (eg, an antivirus sitting on a filtering system behind a gateway MTA
> stopping viruses which can bypass the simple checks offered
> by a MTA --
> zip files for example).
To my mind, the use of AV mail relays is not even remotely like
IDS-Firewalls in scope, technology or implication.
> > vendors think H-IPS (Host Intrusion Prevention
> > Systems) is more exciting - presumably by virtue of being
> > vague.
> Hardening every host is not a bad idea. However, this needs to be
> designed into the system and not patched in from above as a bandaid.
> MAC are a good idea, but in those cases where they are too complex,
> simplistic ACLs can be used instead. These MUST be built into the OS
> kernel and not used as bandages on top of a broken system.
> As MJR argued in the above mentioned thread, trying to fix a broken
> system is a waste of time and not worth the effort.
I see the lines are drawn! ;)
Well, as _I_ said in that thread, it is possible to do a pretty damn good
job of bolt-on protection for both Windows and Linux (the systems that need
it the most), without designing it into the kernel in the first place.
"Dumb" systems like stackguard, linux / windows kernel modules that do some
simple function hooking, detecting system calls made from writeable memory
and the like are NOT rocket science.
These systems provide concrete benefits, and have the advantage of being
available right now. Simplistic systems, many even freeware, can stop about
99% of in-the-wild exploits cold. Personally, I call that "worth the
While wishing for mainstream OS'es with decent memory protection and
security designed in from the kernel, please add World Peace to your list,
and possibly a pony.
> I just had a discussion today with someone who makes money
> cleaning the
> computers of home users from viruses/spamware/crapware. [...]
> his arguments boiled down to
[lambda users are technology challenged]
> Is any vendor offering a usable fix for this type of market
> (small but regular payments from a large volume of customers)?
Yes. Not us, but there are loads of "AV + PFW + Anticrapware" products which
are quite adequate for home users. Hell, the Windows ICF, "High Security"
browser setting and a copy of Spybot is adequate for home users. It's just
that nobody does anything until the fifth time they have had their PCs
cleaned. In fact, probably most of them wouldn't even do _that_ if the thing
didn't start running like a dog.
OK, new thread name, fightin' words, let's go... ;)
firewall-wizards mailing list