Two sides of the security coin
By Robert Lemos
Special to CNET
April 10, 2001, 11:10 a.m. PT

Hackers and security experts may share a similar motto: Know thine enemy.

In February 2000, David Dittrich, the 39-year-old security administrator
for the University of Washington, and "Mixter," a 22-year-old creator of
tools for launching attacks against Web sites, faced off virtually when
Mixter's program--the Tribe Flood Network--was used to inundate Yahoo, CNN
and six other major Internet sites with data.

The denial-of-service attacks slowed access to the sites--and in some
cases made the sites unreachable--for hours at a time.

Dittrich, who had analyzed TFN and other denial-of-service tools, became
the expert of the hour, while Mixter--because the culprit who used his
tools hadn't been found--became its villain.

In a recent interview at the CanSecWest conference in Vancouver, British
Columbia, the two revealed that though they use their skills differently,
Dittrich knows a lot about hacking and Mixter is well-informed about

* When did you start doing security?

Dittrich: I actually sort of grew into it as a by-product of doing
support. I taught myself, then started with the University of Washington
doing support for the Unix workstations, and there were so many Unix
compromises that I had to end up helping people figure out what happened
and how to secure their systems. And it was such fascinating stuff.

* When did you first start seeing the denial-of-service attacks? Your
systems were being used to launch the attacks against the University of
Minnesota, right?

Dittrich: Yeah, actually a little bit before that. We had DOS attacks
going against our systems for years...It wasn't until May or June 1999
that we started seeing Trinoo (an early distributed denial-of-service
tool) on a bunch of systems.

* And then you saw the distributed denial-of-service (DDoS) attacks in
February of 2000?

Dittrich: Yeah, against Yahoo. And that's the thing--everybody says DDoS,
Feb. 8, that's when it happened. But no, it had been going on long before

* Mixter, when did you start doing security?

Mixter: I have been interested in security for many years. In 1997 or '98,
I was on (chat service) IRC and doing pretty much stupid things, and then
basically the police showed up. Actually it was not that much of a
problem. But after that I started seriously getting into coding and

* What did the police say when they showed up? Why did they show up?

Mixter: I did not do intrusions, but I used some German public phone
numbers and then later I found out that I wasn't supposed to use them. At
that time, I was not aware of the legal situation at all. I didn't even
consider what I was doing to be illegal.

* (Outside attack) was always a problem, because our network had no kind
of protection. We were getting viruses and all kinds of things. I got to
analyze an awful lot of intrusions.

Dittrich: Did you ever take programming classes?

Mixter: No, no, no. I started on my own. I was good at...machine language.

I went to college for a year and a half. I think I will do college when I
finally have some success.

* When you did create TFN?

Mixter: When I actually thought about it was in 1999, after all the other
DOS (attacks) went down. I'd always try to go on IRC and talk to other
people and use my reputation or whatever. I got enough information to
relate to what the architecture has to look like. That's when I already
knew something about router programming.

* Are you still maintaining TFN?

Mixter: No. I am now programming for my company. It might become popular
again, so I would rather not.

U So do you consider yourself a black hat (a hacker who breaks into
computers illegally)?

Mixter: No, not at all.

* Gray hat? White hat?

Mixter: Actually, white. But I guess others think gray.

* How about you (Dittrich); are you white hat (a hacker who works to
improve system security)? I saw that you took a black hat at registration.

Dittrich: That's a functional reason. Anything white with me is going to
end up dirty.

No, I used to do little prank things in college, but I never got into
breaking into other people's systems on my own.

* Did you care that TFN was being used to attack Web sites, Mixter?

Mixter: No, at the time I didn't care about the bandwidth attacks when I
made the first version. The second version I made much more technical, so
the script kiddies wouldn't be able to use it. But the first version I
didn't very much want a technical challenge.

I think you really see a small group of people are causing a major amount
of problems.

* What did you think of TFN?

Dittrich: It wasn't used very long. Stacheldraht was much friendlier.

* What are you working on now, Mixter?

Mixter: I am looking at something you could use to make worm packages, but
with more intelligence than those today.

Dittrich: It seems that would be the next step. Automate the creation of
back doors.

* What do you think about people creating tools that can be used
maliciously, like what Mixter did?

Dittrich: Well, there's a lot of riding on the backs of giants that goes
on--taking advantage of people who know something that you can use. But
there is a lot more noise out there that they create, like script kiddie
attacks because they can now do it.

There is some truth in that a lot of these problems, no one sees as being
a problem--like some of these vendors or customers. You go to a software
company and they say, "We don't need to take care of this until it becomes
a problem." They'd much rather add a new feature.

In a way, you almost need something to happen, but it's a waste of money.

* So you need something like the Melissa virus, which didn't do a lot of
damage, but raised awareness?

Dittrich: Yeah, if it had that effect, it is good. But I don't think it is
viable to do that sort of thing for that point.

* So in your mind it's a question of whether the ends justify the means?

Dittrich: I guess a better way to say it is if Mixter is out helping
develop collusion, that's when I have a problem. It's hard, because look
at the amount of time it takes to figure out what happened. It takes a lot
of people to do a lot of work and a lot of skill.

Either apply it creating problems for other people or apply it to creating
solutions. Because if all the people that were out there developing these
thing were out there developing solutions--and all
the little kiddies that were out looking to emulate somebody were
emulating that--then we wouldn't have so many programs that poke holes in

Mixter: There is no relation between people who write the exploits and the
holes in the program. One point why I have given up exploit writing myself
is that it didn't make a difference. If someone found a hole, within two
or three days there would be at least one exploit written.

* Do you regret writing the Tribe Flood Network?

Mixter: No. Maybe the way I published it could have been different. I only
started doing professional security with the company in late 1999.

* You are doing a lot of computer forensics stuff. Are you going to be
doing that for a while?

Dittrich: Yeah, it is a really interesting area. There are a lot of
problems to be solved. There aren't that many people in it who are really
experienced. The administrators don't know how to use simple tools...They
don't know how to think about low-level functions.

I can tell them, "Here is traffic coming from your system. I know your
system is hacked." And they say, "Well, the computer doesn't show anything
like that,'re lying to me."

Then they want me to tell them how they broke in, but you can't do that
unless you have access to the system. And there are only so many people
who do forensics. It is pretty challenging.

* What do you think the biggest problem for security is right now?

Mixter: It's still education, right?

Dittrich: Yeah, probably. Most people don't understand either from the
system owner or the user perspective how the security holes are there.

I keep using the analogy of the Wild West. When people first moved out
here, they had no idea that they had to look out for bears and Indians
running around. It was a pretty hostile environment that they moved into
with whatever skills they had. A lot of people died, trains were being
robbed all the time. It took a long time before the legal structure was in
place or they could protect money transfers and stuff like that. That's
where we kind of are right now.

A lot of people are going to suffer until they realize that the Internet
is a more hostile environment than they first realized.

* So you think that people should be educated before they get online?

Dittrich: I think that we should require that someone show a certain level
of skill before we give them an IP address. There is a huge cost to not
being on the network, so perhaps that will teach them. We have huge
warning labels on hair driers; why not on the Internet?

When I went over to Europe, it really tripped me out. We went up this rail
car to the top of the mountain. There was a family there having a picnic
and there was a little kid dangling his feet over the edge. And my dad
said, "What a terrible father. This kid's going to fall." I think you
teach little kids to be careful around cliffs. You are responsible for

* Do you think companies are standing next to the cliff?

Dittrich: I think companies are running toward the cliff. "Let's put
everything on the Internet" is what they say. 

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