
Feds found Silk Road 2 servers after a six-month attack on Tor? - kryptiskt
http://www.theverge.com/2015/1/21/7867471/fbi-found-silk-road-2-tor-anonymity-hack
======
gwern
OP is wrong. Weaver is (as usual) jumping to conclusions and sensationalizing
(not that he did any of the work to turn up these search warrants or is deeply
familiar with the topic matter... He predicted all the blackmarkets would be
dead by now; how's that going?).

What we know, after I and Moustache and DeepDotWeb have gone through the
warrants & complaints, is that a handful (~78) IPs were deanonymized as late
as July 2014 after accessing the Silk Road 2 vendor .onion. This is almost
certainly due to the UC account 'Cirrus' in some form, who was perfectly
placed to de-anonymize the SR2 servers and insert a payload into the landing
page. A former SR2 employee says they were even using crummy commercial
software like 'DeskPro' on the SR2 servers.

In other words, right now the evidence is consistent with a Freedom Hosting
redux scenario: the FBI has gotten another Tor Browser or other browser
exploit and then phoned home. It _could_ also be the big mysterious attack,
but why would they do that when they had an insider who was involved in hiring
additional employees? And also given that the SR2 vendor onion should have
been seeing a lot of traffic from vendors who almost all preferred to use it
due to better uptime, a mere 78 IPs sounds low.

Further reading:

\-
[https://www.reddit.com/r/DarkNetMarkets/comments/2sppy0/sr2_...](https://www.reddit.com/r/DarkNetMarkets/comments/2sppy0/sr2_buyer_arrested_affidavit_claims_fbi_collected/)

\-
[https://www.reddit.com/r/DarkNetMarkets/comments/2t30hs/the_...](https://www.reddit.com/r/DarkNetMarkets/comments/2t30hs/the_plot_thickens_sr2s_doctorclu_possibly_arrested/)

~~~
na85
What about the "parallel construction" scenario whereby NSA uses their alleged
attack against Tor to deanonymize SR2, and the Cirrus UC is simply a
construction?

Can this be ruled out or unlikely?

~~~
gwern
We can't rule it out, no. Just comment that it does not seem necessary at this
point: Moustache's doxing of scout/Cirrus shows that she could have been
easily busted, we know that she was subverted early on (it was rumored at the
time, in fact - 'emailgate'), once the account was taken over, then it is
perfectly capable of de-anonymizing a server (de-anonymizing is _really_ easy;
I've de-anonymized or helped de-anonymize at least 2 blackmarkets myself, and
actually, just today someone has found another way SR1 could have been de-
anonymized easily, although I can't go into details), and currently the
seller/employee busts are consistent with the Freedom Hosting attack, which no
one needs to ascribe to parallel construction (since we know it was an
obsolete NSA attack which got reused).

~~~
thizzbuzz
What if any steps do you take after de-anonymizing a black market?

~~~
gwern
If the operators seem reasonable, you contact them privately with the IP and
point out the implications. If they don't seem reasonable, you post it on
Reddit and destroy their reputation. Unfortunately, quite a few operators are
fools, knaves, or both.

------
mrb
Edit: Ars Technica also published a nice article about the attack today:
[http://arstechnica.com/tech-policy/2015/01/did-feds-
mount-a-...](http://arstechnica.com/tech-policy/2015/01/did-feds-mount-a-
sustained-attack-on-tor-to-decloak-crime-suspects/)

My technical summary is that we now think it is the feds who initiated this
6-month long attack [1] which consisted in them using _" a combination of two
classes of attacks: a traffic confirmation attack and a Sybil attack."_ They
ran many (115 to be exact) non-exit Tor relays on 50.7.0.0/16 and
204.45.0.0/16 (Sybil attack) to increase their chances of controlling both
ends of a Tor circuit: the first relay (entry guard) reached by the SR2 server
and the last relay used as a hidden service directory where the service is
published. The feds' relays then actively modified traffic to inject a signal
into the Tor protocol headers (bits encoded as a sequence of "relay" and
"relay early" commands) to help them correlate traffic from one end of the
circuit with the other end (traffic confirmation attack). So whenever the SR2
hidden service was being published (which happens whenever the server
reconnects to the Tor cloud?) the last relay knew it was for the SR2 service
(but didn't know the server IP), and could correlate it with the entry guard
which knew the IP address (but didn't know the service name). Once they knew
the SR2 server IP, the game was over.

[1] [https://blog.torproject.org/blog/tor-security-advisory-
relay...](https://blog.torproject.org/blog/tor-security-advisory-relay-early-
traffic-confirmation-attack)

~~~
at-fates-hands
I remember seeing a Def Con presentation about this by the guy who founded
Derby Con. Can't find it right now, but will post it if I can find it again.

~~~
at-fates-hands
Not sure why I can't edit my original comment, but whatever.

Here is the presentation Adrian Crenshaw gave at DefCon 22 called "Dropping
Docs on Darknets: How People Got Caught"

Great presentation:
[https://www.youtube.com/watch?v=eQ2OZKitRwc](https://www.youtube.com/watch?v=eQ2OZKitRwc)

------
Zikes
I'm getting some surprisingly mixed messages on here because I've come into
the discussion with a couple of assumptions, so I'd like to try to clear those
up.

1\. Do we have the right to private, secure, anonymous communications?

2\. If yes, do we have the right to be outraged when our government attempts
to subvert our private communications, most especially with broadly-scoped
warrants or tactics that can expose your communications to any potential
listeners?

~~~
tedunangst
If nobody is trying to subvert your private communications, you don't need
secure private communications in the first place. If you assume you need
secure comms, you should assume people will try to subvert and break your
secure comms.

~~~
nickysielicki
"If nobody is trying to search your home, you don't need locks in the first
place."

~~~
tedunangst
Is that not true?

~~~
paulhebert
I think his point is you can never be sure when someone is trying to break in
to your house/subvert your communications, so it makes sense to take
precautions.

I don't want the government actively working to weaken house lock standards
for a lot of the same reasons I don't want them working to subvert privacy
technology.

Admittedly, in this case the metaphor is kind of flawed since SR2 is the
equivalent of a drug dealer's home, which the Feds would have no qualms about
breaking in to.

------
kilovoltaire
"Silk Road 2 wasn't vulnerable to the same CAPTCHA attack that gave away
location of the first Silk Road's servers"

In case I'm not the only one who hadn't read about how the first Silk Road got
caught, it's simple but interesting:

[http://krebsonsecurity.com/2014/09/dread-pirate-sunk-by-
leak...](http://krebsonsecurity.com/2014/09/dread-pirate-sunk-by-leaky-
captcha/)

~~~
nikcub
It also isn't true:

[https://www.nikcub.com/posts/analyzing-fbi-explanation-
silk-...](https://www.nikcub.com/posts/analyzing-fbi-explanation-silk-road/)

Krebs also posted an update (which he should probably link to from his 'leaky
captcha' post):

[http://krebsonsecurity.com/2014/10/silk-road-lawyers-poke-
ho...](http://krebsonsecurity.com/2014/10/silk-road-lawyers-poke-holes-in-
fbis-story/)

------
geographomics
We know that a global adversary exists, and that Tor is vulnerable to certain
types of attacks by such an adversary (e.g. [1,2]). Given that the list of
relays is public by design, that their (albeit encrypted) communication can be
monitored by the adversary, that popular hidden services will be moving a
significant amount of traffic to and from a single static IP address in a
manner modifiable by any user of it, and that there are known methods of
disrupting hidden services to effect a global change in this [3] - it follows
that such hidden services are rather more vulnerable to deanonymisation,
compared to most other users. Seems like running one is an incredibly risky
thing to be doing.

[1] [http://cryptome.org/2013/08/tor-users-
routed.pdf](http://cryptome.org/2013/08/tor-users-routed.pdf)

[2]
[https://mice.cs.columbia.edu/getTechreport.php?techreportID=...](https://mice.cs.columbia.edu/getTechreport.php?techreportID=556&format=pdf)

[3] [http://donncha.is/2013/05/trawling-tor-hidden-
services/](http://donncha.is/2013/05/trawling-tor-hidden-services/)

------
Zikes
So the FBI knowingly attacked a civilian communications network, potentially
causing a great deal of harm to the entire network in order to catch a few bad
apples.

Like nuking a city because you're pretty sure you'll get a few bad guys.

~~~
JohnTHaller
Over 80% of Tor hidden service visits are related to child pornography.* A
'few bad guys' is stretching things a bit. Additionally, they didn't nuke
anything, Tor continued to function, albeit with a wide open security flaw
that multiple actors besides the ones mentioned here were exploiting.

* [http://www.wired.com/2014/12/80-percent-dark-web-visits-rela...](http://www.wired.com/2014/12/80-percent-dark-web-visits-relate-pedophilia-study-finds/)

~~~
Zikes
And over 70% of emails are spam[1], so we should route every email we send
through the FBI/NSA?

That other 20% of Tor usage may very well be political dissidents,
whistleblowers, or average Joes that just don't want half the world watching
everything they do and say online.

[1]
[http://www.kaspersky.com/about/news/spam/2013/Spam_in_Q2_201...](http://www.kaspersky.com/about/news/spam/2013/Spam_in_Q2_2013_More_offices_in_danger_from_targeted_plausible_fakes)

~~~
bigiain
"That other 20% of Tor usage may very well be political dissidents,
whistleblowers, or average Joes that just don't want half the world watching
everything they do and say online."

Or me, browsing my local government website to check when the next recycling
pickup day is. Because I feel some kind of duty to do my bit to make the
entirely innocent portion of the haystack bigger...

