Owning Bad Guys {& Mafia} with JavaScript Botnets
Chema Alonso ( chema@informatica64.com @chemaalonso) and Manu "The Sur" ( mfernandez @ informatic a64. com )
Informatica 64 ( http://www.informatica64.com)
Abstract: "Man in the middle " attacks are common and dangerous. Using a TOR
connection or an Anonymous Proxy Server implies accepting a "man in the
middle " schema in our Internet Connection. In this paper we describe how easily
a JavaScript Botnet can be constructed and what are the risks. Moreover, we
describe, with samples, what kind of people are using this kind of services.
Botnets
Building a botnet is an idea that everyone working in
security has thought about, c. The idea of having a control
panel that allows you to manage the behaviour of thousands
of machines is tempted ... However, this process is
definitively a step to the side of cybercrime, and must be
very careful not to do.
Despite this, the proof of concept I will relate in this article
has to do with this idea, to make a botnet, but with a
complete different philosophy. First, on our proof of concept
work that is done is completely passive, it means, there is no
intention to control the lives of anyone, but to study the risks
of certain services that have become too popular, such as
"Anonymous Proxies" and TOR networks.
All this work is intended to alert of the risks to which may
be incurred by the mere fact of following one of the many
tutorial available on Internet about anonymity. That said, I
will tell you the process we followed to make a botnet to
control what they do and how they do, that bad guys of
Internet.
Man In The Middle
Before describing the architecture is necessary to review the
concept of "Man in the Middle" techniques. In the
networking field, "Man in the Middle" attacks are popular
and effective. Typical cases in IPv4 networks with ARP
Spoofing techniques or Rogue DHCP, in IPv6 networks
with ICMP Spoofing attacks or SLAAC, or other cases such
as DNS Poisoning are widely used in schemes to steal
credentials.
"Man in the middle" scheme in networks, spread with the
cybercrime world to "Man In The Browser". For a long
time, "the Russian school" was beating those systems with
Internet Explorer 6 by using the famous Browser Helper
Objects (BHO) - Active X components -, just like a browser
toolbar took control about everything going on in the
browser, in order to replace and inject HTML code in
websites of financial institutions and steal login credentials.
This scheme of business was extended to mobile devices,
where it is known as "Man In The Mobile", since in order to
control economic transactions of many banks was necessary
to steal the bank confirmation SMS.
Man in the Tab
Even more subtle are the techniques of "Man in the Tab" or
"JavaScript in the middle", also known as cache poisoning
browser. In these cases, the attacker does not control entire
browser, but its only area of work is the content of a tab, that
is, it has managed to put malicious code on the user tab,
allowing they to do all the things that can be done with code
on a web page loaded in a web browser.
These attacks are commonly used in XSS schemes, where
the attacker injects code that runs in the browser tab.
Another common way, is to own legitimate web servers to
put a JavaScript code, which is responsible for redirecting
visitors to a web server where the exploting kits were
deployed. This is something very common in distribution of
malware operations.
$ Trojan :JS/Redirector.GA (?)
Encyclopedia entry
Published: Sep 30, 2010
Aliases
Alert Level (?)
Ant! ma I ware protection details
Microsoft recommends that you download the latest definitions to get protected.
Detection Initially created:
Definition: 1.91.891.0
Released: Sep 30, 2010
Figure 1: Trojan JS/Redirector.GA
But there are even malware whose operation is based
entirely on that, a file cached in web browser to load
malicious JavaScript on a regular basis on the tabs to get
their executions. Thus, malware as Trojan horse: JS /
Redirector.GA [1] took care to put the Google Analytics
JavaScript file, widely used on many web sites, as this
trojan-blog, loading a malicious payload from a server
controlled.
Once inside
In an environment that has been infected with a JavaScript
file loaded in the page, the many things that can be done are
more than enough to please the attacker. First, to be within
the domain allows Javascprit code to access all the cookies
that are not tagged as HTTP Only, and even others if the
conditions are present for TRACE attack [2], or make an
Error 400 attack in Apache[3] or loading a Applet[4] or... Of
course, it is possible to make Clickjacking attacks, Phishing,
to steal data that has been typed, to intercept forms, to load
code from remote servers, etcetera.
In order to generate attacks in these environments there are
advanced solutions such as BeEF (Explotation Browser
Framework)[5] that contains a good amount of payloads to
use in case you get the malicious js file.
Figure 2: BeEF Project
How to make a botnet with this idea
Moving from an environment that specifically infects a
JavaScript file, we decided that the best way to create the
botnet would be if bots did "motu proprio", it means, not a
forced man in the middle, but chosen by themselves. Hereby
we decided to focus on the TOR network and Proxy servers
used on the Internet.
For its implementation, we assemble a machine, which
would be the "Man in the Middle", and enrolled as TOR
node and as an Anonymous Proxy Server, and in both cases
was operating for a while. However, we must say that with
TOR node, we suffered a detection of malicious activity that
makes that our IP address was ignored.
Figure 3: DNS test log in TOR
Security systems in TOR networks launch periodic and
more or less random tests, in which the answers are known
beforehand, and if they are handled or manipulated in some
way, then the node loses confidence and it is blocked. In our
case, we "tweak" the answer to certain domain names and
stopped sending traffic through our node. Good for them!
However, with proxy servers on the Internet the things were
different...
Architecture of the solution: Infection of JavaScript
To achieve the goal of being able to infect clients with
malicious JavaScript files should ideally not add a new file,
but to modify JavaScript files that pass through the
Malicious Proxy server by adding some code to load a
payload each time bots execute this code in a browser tab.
That is, using a schema similar to the following image:
Figure 4: Malicious Proxy architecture
This means that the architecture does modify the code of all
JavaScript files that passes through the Proxy server to
dynamically load the payloads to be set later with a control
panel as BeEF.
Setting the proxy server: SQUID
To get JavaScript files rewritten, the steps were:
1 ) Download ilsc file from its original location.
2) Save it to a temporary location.
3) Add the JavaScript infection code at the end of the
JavaScript file.
4) Make that file has an expiration date of 3,000 days.
5) Deliver to the clients the new created JavaScript file.
In order to perform all these steps, the first thing to do is
select the server option URL_Rewrite_Program of SQUID,
which lets you run a program to rewrite the files that match
a certain condition. In this case, the rule applies to all files
and used a Perl program called poison.pl.
Figure 5: squid. cant file with activated iirl_rewritc_i>rograin
The file poison.pl performs steps 1 to 5 (with the exception
of step 4) of the process described above. To do this, first
check that the file name ends in .js with a small regular
expression. Once the file is met JavaScript, the program will
download it from its original location, copy it to a temporary
location, change its permissions to write it and dumps the
contents of file infection, which in our example is called
pasarela.js
Figure 6: poison.pl module infects JavaScript files
The last step is modify the expiration date of the objects. It
requires installing "mod_expires" module into Apache, and
to make a little change in the file .htaccess at location from
which will serve all the JavaScript infected files.
Figure 7: Mac ess fil, t temporal
The infection
Finally, note that all that is necessary to infect JavaScript
files, is something called pasarela.js and all it does is
loading the poisoned payload.php from malicious server and
report their identity loading an image with jsonip.php.
created or not. The goal is to not run the code of the
And now... how to get someone become infected with this
Malicious Proxy?
Distributing the Proxy server in Internet
To get the "bad guys" do use of our Malicious Proxy server,
the idea was very simple: We registered it on one list of
proxy servers . For a long time, and in many sites and blogs,
it is recommended the use of proxy servers to get
anonymous IP address, which is common for many of us to
do, and I have to include myself. We selected a site at
random and we register the IP address with port 31337, to
attract a little more attention.
Figure V: Proxy servers service
These sites with lists of Proxy servers perform security
testing to the new Proxy Servers, but the test are not as good
as those made in the TOR network. In fact, the real problem
is not the place where the proxy server is registered do the
tests or not, but once it gets on the list, there are hundreds of
sites and applications that are downloading these lists
without any verification of safety.
Simply pass the first test, which from what we saw was test
of connection and functionality, and the "Magic of the
Internet" will make your IP address appears on thousands of
sites, such as what happened with our IP address.
Busqueda [ ]
Shoppm9 |r*«WsKSn e Country'^ ' » 2< ... '
Figure 10: Rogue Proxy IP appeared in thousands of sites
Expansion of the botnet
Once there was the mass distribution of the IP address, the
rest of the work was waiting to see how many "bad guys"
began to be infected by JavaScript code. To see that, it was
implemented a small panel in PHP - that was hacked by
Spanish hackers later, just after we show it in our talk in
RootedCON [6]. Don't trust on Spanish hackers!-, which
accounted for the bots that had ever requested payloads and
those who had requested them in the last 24 hours.
The number of computers that were infected were so high at
the beginning, that knock down our panel, so we had to
optimize some queries, and be much more selective in the
connections and the data to be captured, so as not to
overwhelm our small server with many data.
Figure 11: Map of active hots by countries
Here you can see how the panel reached one of the moments
about 5,000 bots with nearly 1,000 of them active in the last
hour. As you can see, to make an analysis of the origins of
connection, Russia, Brazil and Indonesia were the most
active when using these services. Interestingly match source
of much malware.
Making payloads
Once we had entered the pasarela.js in the browser ... What
could be done from there? The volume of ideas that you
may occur is huge. From making DDOS attacks, until make
defacement of the sites visited by the bot, phishing attacks to
steal login credentials of special sites or steal cookies from
the session.
As we had no intention of doing anything wrong with this,
and our goal was to do an experiment to see what kind of
things were done through the Internet Proxy servers, only
started a couple of payloads.
1) Identification of bot, and theft of cookies that were
not HTTP Only and its URL.
2) Theft of data sent by loaded HTTP forms.
Identifying bot and URL of connection
We left out of the payloads the HTTPs connections and
HTTPOnly cookies, because we had no actual real target,
and because it was sufficient as sample to obtain that
information.
Thus, the first payload identification only did this:
document. write("
");
Allowing us to know which URL was connecting and if he
had any unsafe session cookie. This information allows us to
find things very juicy and discover a new Internet full of
URLs that we had not visited before.
Grabbig data from the forms
To get data filed from forms, a small script was generated
which hook submit events of the forms, with this simple
JavaScript code.
Figure 12: Script to hook submits fields of the forms
And the rest was to discover what is done through an
Anonymous Proxy Server on the Internet ... What did we
found there?
Who uses the Internet Proxy server?
The main reasons to use an Internet Proxy Server are usually
two. The first of these is obviously hiding the source IP
address of the connection. Such users are seeking will
certainly not leave the IP address of the initial connection to
a log file that can point directly to them. The second reason
is often to jump/avoid access restrictions on the network
connection, i.e. users who want to bypass any security
restriction in any organization in order to connect to sites
not allowed by the network administrator.
With this type of base motives, the type of users of our
Proxy Server was the most colourful, leaving a good
collection of data that is worthy to study deeply. Between
the most striking we found the following:
Scam artists: The Nigerian scammer
One of the users of such Internet Proxy Services proved to
be a man that allegedly was selling Visa Cards for working
at UK, with IP address from India. To do that, he was
making an intense campaign of spam with an e-mail
message requesting payment for Western Union.
Figure 13: Spam scam campaign <>'<»' request money
Of course, some recipients of the messages were quite
sceptical and their responses were very negative, but we
could see how some people paid and sent all data to obtain a
Visa that would never come.
Scam artists: The horny chick you get off with tonight
Another type of scam artists with whom we met are
dedicated to keeping fake profiles of women in different
social networks of sentimental contacts. In each, the
location, name and age of women were different.
In fact, the same person kept profiles with different types of
women, allowing it to open the range of victims.
Hacked hackers hacking
Figure 15: Rogue profile number 1
For reasons of space I show you only a couple of profiles of
all we found that are maintained by the same person.
Figure 16: False profile number 2
In this case, its business model was very similar. Making a
working day, this German crock, is dedicated to linking
people and ask for money through Western Union to pay for
the trip to where the victim lives and spend a night of mad,
wild, nasty love.
As had many chance encounters, he organised conversations
and stores them. Some are like this, in which insistently
sought money in exchange for some alleged "nicked"
(naked) photos. In the chat you can see that, as it should be
chatting with several at once, sometimes it plays dirty tricks
and puts things in their native language.
Figure 17: ,1 dial lag talking la a victim
The number of chats, and requests for money by Western
Union did was very high, making this system a real work
night shift.
These two types of scams are among the many we saw,
where we found that it made all kinds of scams, such as
sales of dogs, fake vehicles, etcetera. A real amount of
business, we did not know previously. Financial crisis what?
Worried about anonymity
Many of the users who came to do something "illegal", the
first thing they did was check their IP address with websites
such as Whatismyip.com checking whether they are
anonymous or not or using others similar websites, but in
the end, apparently seen, not only should check their IP
addressing.
One of the issues that caught our attention as we hoped was
to find many hackers using WebShell through Proxy Servers
to deface websites. Among them, we have chosen this
defacement that we saw how it was made in real-time.
Configuration.
Her r^rP Sorunda Hizmetinizdeyiz.
eVeriaveOlusaD
iletisim icin: Bv BuR.tK ii Homuil.Dc.
Figure 18: Hacker 's defacement
When we look at why he had been infected, we realized that
he was using an infected WebShell loading a JavaScript file
to report the URL of the WebShell. This JavaScript file was
also infected by our Proxy Server, and allows us to discover
where the webshell was.
ea»—. :j.i! Technology C:jic.- ■
Mission Apj
s
Figure 21: Loaded JavaScript files loaded in
For example, in this site it can be seen that in the login page,
JavaScript files are being loaded statically, that is, it always
loads the same files, allowing attackers to force a pre-
caching of all of them to all the victims they want to infect.
To do this, the control panel would have a payload in
JavaScript to do something like:
document. write( Kscript
src=http://w\vu \oh fi'i ivo.com/target.js >);
This file will be also infected, and the attacker could run any
payload in the future within the targeted domain, even if the
bot is disconnected form the Rogue Proxy Server.
Dynamic JavaScript files
Sites like Facebook load javascript files using names that
change dynamically, which prevents it from caching the
JavaScript file previously, so this attack cannot be done.
Figure 22: JavaScript files leaded in i'acehook S lo^in
However, the list of sites that use static JavaScript files, in
login pages of banks, institutions, companies, etcetera, is
huge, and it should not be a security vulnerability if users
are not infected, but it helps Javascript botnets to perform
targeted attacks.
Previously cached JavaScript files and HTTPs
One of the things that we did not implemented in this proof
of concept was to force to cache the infected file if it was
already in the browser cache. Assuming that a site loads a
JavaScript file that the browser has already cached, the
client will not request that file, so it would not become
infected. However, playing with HTTP Etags options would
be possible to force the browser to request the new files, but
this wasn't implemented in this proof of concept.
Moreover, to avoid arousing the slightest suspicion, we
decided not to intercept HTTPs communications, leaving
out of reach any secure connection and any cookie marked
with the "Secure" flag. Do not forget that this was just a
POC.
Final recommendations
Both the TOR networks and Proxy systems represent "Man
in the Middle" schemes, in which you must trust to use
them. Put a malicious server on Internet is too easy as to
think that there is not being made, in a massive way, by
people with the worst of the intentions of all, so if you use
any of these facilities, it is best to get ready to be attacked.
No surfing with out dated systems for these networks,
firewalls and anti-malware always in alert, and remember
when you finish to use of them should take precautions for
disinfection. As recommended by default, clear the cache for
each browser session, and always use the private browsing
mode.
Greetings
We would like to say thanks, to Jon, Antonio, Pedro and
Isabel of JAPI Tracing, to people working on BeEF,
colleagues form Informatica64 and Manu and Frank for
helping us to improve the security of the C&C.
References
[1] JS / Redirector.GA
https://www.microsoft.com/security/portal/Threat/Encyclop
edia/Entry.aspx?Name=Troian%3AJS%2FRedirector.GA&
ThreatID=-2147328473
[2] XST Attack
http://iererrriahgrossman.blogspot.com.es/2007/04/xst-lives-
bypassing-httponly.html
[3] Apache HTTP Only Cookie Disclosure
http://fd.the-wildcat.de/apache e36a9cf46c.php
[4] Gaining Access to HTTP Only Cookies in 2012
http://seckb.yehg.net/2012/06/xss-gaining-access-to-
httponly-cookie.html
[5] BeEF Project
http://beefproiect.com/
[6] RootedCON
http://www.rootedcon.es