Thursday, September 27, 2007

Snort 2.8 is out

Grab it from the Snort download page, and read my previous post about some of the new features.

I still haven't tried this myself yet, but soon. Honest.

Thursday, September 13, 2007

I call shenanigans!

The Telegraph reported yesterday that aerospace giant EADS has developed "the world's first hacker-proof encryption technology for the internet" [sic].

Amazing! There are at least three separate errors in just that one 10 word sentence fragment. I tried to find some more info on the company's website, but all I could find was this year-old press release on a product called ECTOCRYP. I assume this to be the same product, because how many encryption protocols would this company develop? Let's take a look at some of the problems with this company's statement.

First off, as everyone reading this post probably already knows, there's no such thing as "hacker-proof". The definition of a hacker is someone who can change the rules of the game in his or her favor, so in order to be "hacker-proof" you've got to somehow deny them this opportunity. Most knowledgable attackers realize that attacking the encryption algorithm itself is usually unnecessary. For example, in order to be truly "hacker-proof", you must not only have a robust algorithm, but also perfect key management (both protocols and implementation) and secure endpoints on both sides of the communication. This last, by the way, also implies users and administrator who never make any mistakes in configuration or use of the system.

The second problem is that "world's first" thing. Probably the most commonly deployed encryption technology today is SSL, and let me tell you, it's pretty much "hacker-proof" if you are just trying to cryptanalyze a captured session, which, as I just mentioned, you probably wouldn't do.

Along the same lines, here's a quote from the article:

At the heart of the system is the lightning speed with which the "keys" needed to enter the computer systems can be scrambled and re-formatted. Just when a hacker thinks he or she has broken the code, the code changes. "There is nothing to compare with it," said Mr [Gordon] Duncan [the company's government sales manager].

So their big innovation is that they change the keys frequently? It's true, there's nothing like it... except for all the things that already do that! TKIP has been doing this for years ("T" is for "Temporal", and that's good enough for me). Even SSL can do this (via it's key renegotiation protocol), though this is admittedly rare since most SSL sessions are too short.

Finally, I'm impressed that they've developed an encryption technology "for the internet". IPv6 or IPSEC might be "for the internet" in the sense that they're tied directly to network protocols used to communicate over the Internet, but that doesn't seem to be the case with ECTOCRYP. It's probably just a stream or block cipher, which could be used equally well on, say, a dedicated serial line. I think what they mean to say is that it's a protocol used for protecting information in transit, as opposed to encrypting files at rest on the disk. That doesn't mean that it's designed "for the internet".

All of this is totally beside the main point, however, that I couldn't find any technical details on the encryption algorithm itself. I'm no professional cryptographer, so perhaps it has been published in a trade journal somewhere that I can't find in Google, but compared to other widely available encryption algorithms, I doubt it has undergone much peer review. This in itself makes the system suspect.

By the way, if you do Google "ECTOCRYP" you'll find this craptastic marketing video.

Tuesday, September 11, 2007

The embassy password thing

I wasn't going to comment on this, but we were discussing it a bit on #snort-gui today, and it made me wonder...

People everywhere are talking about how the embassies are foolish for using Tor to provide "secure" remote access to their systems. Ok, we can all agree that Tor isn't really suitable for that. But as someone on #snort-gui pointed out, how do we know it was an official embassy-supported application, and not just some power users who decided to start using Tor on their own? We don't! At least, I couldn't find any confirmation that the network admins were pushing Tor on their users.

But really, this got me thinking some more this afternoon. How do we know it was the embassy users who were using Tor? If I were a hacker who had somehow gained access to accounts in the embassies, I might use Tor to disguise my origin and wouldn't care if the passwords were exposed. I think there are any number of actors who could be behind this, so I don't want to name any names, but Certainly, Hacking Insecure Networks Around the world is a specialty of some...

Update 2007-09-11 16:02: giovani from #snort-gui reminded me that he was the one who brought up the idea of the power users. And he is unnervingly happy about being referenced here, even indirectly. Thanks, giovani!

Would you notice this?

Just a quick thought I had. If your organization is using virtualization to pack many VMs onto your existing server platforms (as many sites are trying to do these days), would you necessarily notice if an additional VM popped up?

It turns out that VMs can be very small (the smallest VMWare image I found with a quick google search was 10MB, which could fit in my /tmp partition). Many, perhaps all, of the VM packages provide command-line level access to manage the running guest systems. VMWare even provides a Perl API for this.

If I were an attacker who managed to get access to your VM system, could I insert my own VM image and make it run? If so, I could potentially have my own custom hacking environment, with root privileges and whatever software I needed, without creating too many files or new processes on the host OS. Unless you're looking carefully at every file on the system, or watching what VMs are running, would you notice?

Would anyone with real-world virtual server experience care to share their thoughts?

Find Storm with Sguil (and a little ingenuity)

My friend nr has started a new security blog. His first real post is about using Sguil to detect Storm worm infections. Welcome to the blog world, nr!

Thursday, September 06, 2007

Cloaking your investigative activities in Sguil

I've written before on disguising your outbound DNS queries. In short, even looking up an IP to find the hostname might alert an attacker that you're on to them if they control their own DNS server. I briefly described how to create a simple proxy DNS server that could send all your queries through a third-party, like OpenDNS, which should make it harder for the bad guys to figure out just who is checking them out.

I'm happy to say the new Sguil 0.7.0 client now incorporates third-party DNS server support natively. In sguil.conf, you simply set the EXT_DNS, EXT_DNS_SERVER and HOME_NET variables, like so:

# Configure optional external DNS here. An external DNS can be used as a
# way to prevent data leakage. Some users would prefer to use anonymous
# DNS as a way to keep potential malicious sources from knowing who is
# interested in their activities.
# Enable Ext DNS
set EXT_DNS 1
# Define the external nameserver to use. OpenDNS list and
# Define a list of space separated networks ( that you want
# to use the OS's resolution for.
set HOME_NET ""

In this example, I've configued Sguil to use one of the OpenDNS name servers ( to look up all hosts except those on my local LAN (addresses in either the or the range).

So that takes care of DNS, but what about WHOIS? Ok, so maybe it's a bit less likely that the attacker has also compromised a WHOIS server, but less likely doesn't mean that it hasn't happened. It probably has, and it probably will in the future. Therefore, it's prudent to also try to disguise the source of your WHOIS lookups.

Sguil has always had the ability to call a user-supplied command to perform WHOIS operations, so here is a simple script you can use to proxy all of Sguil's WHOIS lookups through a third party (Geek Tools, in this case). This should work on any version of Sguil.

# Simple script to proxy all whois requests through
# to help keep the bad guys from figuring out that we're onto them when
# Sguil looks up a record.
/usr/bin/whois -h $*

To use this, just set the WHOIS_PATH in your sguil.conf file, like so:

set WHOIS_PATH /home/sguil/bin/

So now you have it. By implementing DNS and WHOIS proxies in Sguil, you can add an additional layer of protection against bad guys who may be monitoring their systems for signs that you have discovered their attacks.