Google as a hacking tool

Google: A Hacker's Best Friend
In the last few years a number of news articles appeared that warned of the fact that hackers (or
crackers if you will) make use of the Google search engine to gain access to files they shouldn't be
allowed to see or have access to. This knowledge is nothing new to some people but personally I have
always wondered how exactly a thing like this works. VNUnet’s James Middleton wrote an article in
2001 talking about hackers using a special search string on Google to find sensitive banking data:
"One such posting on a security newsgroup claimed that searching using the string 'Index of /
+banques +filetype:xls' eventually turned up sensitive Excel spreadsheets from French banks. The
same technique could also be used to find password files"[1]
Another article that appeared on wired.com told us how Adrian Lamo, a hacker who made the news
often the last couple of years, explained that Google could be used to gain access to websites of big
corporations.
“For example, typing the phrase "Select a database to view" -- a common phrase in the File Maker Pro
database interface -- into Google recently yielded about 200 links, almost all of which led to File Maker
databases accessible online.”[2]
These articles kept on coming up in the online news. U.S. Military and Government websites were
vulnerable because admin scripts could be found using Google, medical files, personal records,
everything suddenly seemed just one Google search away. But these articles seemed to show up once
every half year and always talked about it as if it was something new. Another thing was, the articles
never explained how one would actually go about doing this. Almost never an example of a search
string was given. The last time I read one of these articles I decided it was time to find out for myself,
whether Google actually could do all they say it can. The following is a report of my findings and a
description of some techniques and search strings one could use.
Theory
The theory behind this is actually quite simple. Either you think of certain data you would like to
acquire and try and imagine in what files this kind of data could be stored and you search for these
files directly. (Search for *.xls files for example) Or you take the more interesting approach and you try
to think of a certain software that allows you to perform certain tasks or to access certain things and
you search for critical files of this software. An example could be a content management system. You
read up on this particular content management system, check out of what files it exists and search for
those. A great example is that of the databases mentioned above, where you know the string “view
database” is used on pages that shouldn’t be accessible to you and you then search for pages
containing that string, or you check the software and notice that the option to view a database is linked
on a web page within this software called “viewdbase.htm” and you search for “viewdbase.htm”
The most important thing is to have a clear goal, to know what it is you want to find. Then search for
these specific files or trademarks that these files have.
Google Search Options
Specific file types: *.xls, *.doc, *.pdf *.ps *.ppt *.rtf
Google allows you to search for specific file types, so instead of getting html-files as a result (websites)
you get Microsoft excel files for example. The search string you would use would be this:
Filetype:xls (for excel files) or filetype:doc for word files.
But maybe more interesting would be searching for *.db files and *.mdb files. Google by the way
doesn’t tell you you can search for *.db and *mdb files. I wonder what other file types one can search
for. Things that come to mind are *.cfg files or *.pwd files, *.dat files, stuff like that. Try and think of
something that might get you some interesting results.
Inurl
Another useful search option is the inurl: option which allows one to search for a certain word one
would want to be in the url. This gives you the opportunity to search for specific directories/folders,
especially in combination with the “index of” option, about which I will talk later on.
An example would be inurl:admin which would give you results of website urls that have the word
“admin” in the url.
Index of
The index of option is another option that isn’t especially thought of by the creators of google, but
comes in very handy. If you use the “index of” string you will find directory listings of specific folders on
servers. An example could be:
‘index of” admin or index.of.admin
which would get you many directory listings of admin folders. (don’t forget to use the quotes in this
case since you are looking for the entire “index of” string, not just for “index” and “of”)
Site
The site option allows you to come up with results that only belong to a certain domain name
extension or to a specific site. For example one could search for .com sites or .box.sk sites or .nl sites,
but also for results from just one site, but more interesting might be to search for specific military or
government websites. An example of a search string would be:
Site:mil or site:gov
Site:neworder.box.sk “board”
Intitle
Intitle is another nice option. It allows you to search for HTML files that have a certain word or words in
the title. The format would be intitle:wordhere. You could check out what words appear in the title of
some online control panel or content management system and then search google for this word with
the intitle option, to find these control panel pages.
Link
The Link option allows you to check which sites link to a specific site. As described in Hacking
Exposed Third Edition, this could be useful:
These search engines provide a handy facility that allows you to search for all sites that have links
back to the target organization’s domain. This may not seem significant at first but let’s explore the
implications. Suppose someone in an organization decides to put up a rogue website at home or on
the target network’s site.“”[4]
Combining search options
The above mentioned search options might or might not be known to you, but even though they can
amount to some interesting results, it’s a fact that when you start combining them, that’s when
google’s magic starts to show. For example, one could try this search string:
inurl:nasa.gov filetype:xls "restricted" or this one: site:mil filetype:xls "password" or maybe
site:mil “index of” admin
(I’m just producing these from the top of my head, I don’t know whether they’d result in anything
interesting, that’s where you come in. You got to find a search string that gets the results you want.)
Examples; The Good Stuff
Specific file types: *.xls, *.doc, *.pdf *.ps *.ppt *.rtf
To start out simple, you can try and search directly for files that you believe might hold interesting
information. The obvious choices for me were things like:
Password, passwords, pwd, account, accounts, userid, uid, login, logins, secret, secrets, all followed
by either *.doc or *.xls or *.db
This led me to quite some interesting results, especially with the *.db option but I actually also found
some passwords.doc files, containing working passwords.
http://www.doc.state.ok.us/Spreadsheets/private%20prison%20survey%20for%20web.xls
http://www.bmo.com/investorrelations/current/current/suppnew/private.xls
http://www.nescaum.org/Greenhouse/Private/Participant_List.xls
http://www.dscr.dla.mil/aviationinvest/attendance_5Apr01.xls
http://web.nps.navy.mil/~drdolk/is3301/PART_IS3301.XLS
Admin.cfg
Admin.cfg is, most of the times, an admin configuration file of some sort. Many different software
obviously use names like “config” or “admin” or “setup”, etc. And most of the times these files contain
sensitive information and thus, shouldn’t be accessible for people browsing the web.
I tried a search for admin.cfg, using the following search string on google:
inurl:admin.cfg “index of”
This led me to many results of which many were useless. But some paid out.
I found for example: http://www.alternetwebdesign.com/cgi-bin/directimi/admin.cfg
Which contained a password. This was the admin password for a database located at
http://www.alternetwebdesign.com/cgi-bin/directimi/database.cgi?admin.cfg
This database contained sensitive client data of this particular company. I then proceeded to e-mail
the company and tell them about the flaw. They replied to me in a very friendly manner and told me
they appreciated my help and that they would take the necessary steps to solve the problem.
Webadmin
A short while back, while working on this article, I ran into this website:
http://wacker-welt.de/webadmin/
The website explains that “webadmin” is a small piece of software that allows one to remotely edit
parts of a website, upload files, etc. The main page for the web admin control centre is called
‘webeditor.php”. So obviously, my next step was to visit Google and use the inurl tag to find
web editor.php pages that I could reach. I used the following search string:
inurl:web editor.php
and I found the following results:
http://orbyonline.com/php/webeditor.php
http://www-user.tu-chemnitz.de/~hkri/Neuer%20Ordner/webeditor.php
http://artematrix.org/webeditor/webeditor.php
http://www.directinfo.hu/kapu/webeditor.php
All these webeditor.php files were reachable by anyone, merely because the owners failed to
(correctly) protect these pages by using .htacces. This mistake allows whomever to change the
web pages on the server and thus defacing the site, uploading files and thus possible gaining full
access to the server.
In browsing through these sites I noticed that the file that allows one to upload files is called
“file_upload.php”, which I could then search for at Google and find more examples.
http://www.hvcc.edu/~kantopet/ciss_225/examples/begphp/ch10/file_upload.php
A good example:
http://www.pelicandecals.com/admin/webeditor.php
The script allows you to change files, like in the above examples, including the index.php.
In theory one could write or download whatever malicious script one wants, paste this code into an
existing file or just upload it and well, the consequences are obvious.
t
here was also a link “Return Administration” and clicking on it took me to:
http://www.pelicandecals.com/admin/administration.html
Where there were customer addresses, where one could change pricing, etc.
Content Management Systems
Content Management Systems are software programs that allow a webmaster to edit, alter and control
the content of his website. But the same goes for online control panels of websites.
The idea is to find out what files are for example the main files of these software programs.
“cms.html” could be one or “panel.html” or “control.cfg” You find out what file names a certain package
uses, you then think of a good search string and hope you strike gold.
Frontage Server Extensions HTML Administration Forms
“You can remotely administer the Front Page Server Extensions from any computer connected to the
Internet by using the Front Page Server Extensions HTML Administration Forms, a set of Web pages
that allow you to administer the Front Page Server Extensions remotely.[3]
Well, that’s what Microsoft’s manual has to say about it. This means, users with access to these forms
are able to perform a number of administrative functions, remotely. And that means, these forms
should be well protected from non-authorized people. Now how would one go about finding non protected
forms over the internet? The first thing we do is try to find out what files these scripts consist
of. A short visit to the Microsoft website or a peek into the frontage manual tells us that the main page
for these administration forms is a file called “fpadmin.htm”. So that’s what we need to search for.
Now to find a correct search string that will get us the results we want. When a default install is
performed, the files get installed in a directory called “admin”. Putting to use what we have learned
about Google search options and the theory behind this technique, a good search string might be:
inurl:fpadmin.htm “index of” admin or maybe inurl:admin/fpadmin.htm
Well, these were the results I got:
http://www.lehigh.edu/~ineduc/degree_programs/tbte/admin/
http://blackadder.eng.monash.edu.au/frontpage/admin/
http://www.lehigh.edu/collegeofeducation/degree_programs/tbte/admin/
http://www.vsl.gifu-u.ac.jp/freeman/frontpage4/admin/
http://www.tech-geeks.org/contrib/loveless/e-smith-fp-
2002/frontage/version5.0/admin/1033/fpadmin.htm
http://fp.nsk.fio.ru/admin/1033/fpadmin.htm
But the frontage manual says more:
“Because of the security implications of making remote Front Page administration possible from Web
browsers, the HTML Administration Forms are not active when they are first installed.”[3]
This means that some of these could be active and thus useful to us and some might not.
There is of course, only one way to find out and that is to perform one of the possible administrative
functions and see if you get results. I for one decided not to go that far, because it would mean
breaking the law. But I’m not here to teach ethics, or at least not today.
Freesco Router
The Freesco router software for Linux as a default, installs a small web browser which allows owners
to control the router through the http protocol. In other words, a website automatically gets setup that
allows you to control the router. The default password and login for this control panel is “admin” and
“admin”. Many people who use freesco don’t know this. You could search for these Freesco router
control websites by using a string such as:
intitle:”freesco control panel” or “check the connection” which are words that either are in the title of
these pages or on the pages itself. That’s what it’s all about; you check out a certain software, find the
part you’d want to be able to reach and figure out which search string would get you the good results.
Extra Tips
• Remember English is the most used language online, but it’s not the only one. Try and search
for words or strings that are specific to your language or French or German, etc. For example
“beheer” is a Dutch word for “administration” or “privat” is German for “private”.
• You can check vulnerability scanners’ scan lists for interesting search strings you might want
to use or combine with your own strings. Check http://paris2k.at.box.sk/tools/listings/ for some
examples.
• Search for files like “config.inc.php” or “mysql.cfg” that could contain mySQL password and
username combinations. Try to think of good search strings using words like PHP, SQL,
mySQl, etc.
• Try things like: inurl:admin "index of" "database" or inurl:phpmyadmin "index of" or inurl:mysql
"index of" site:neworder.box.sk intitle:index.of or intitle:index.of.private( = intitle:"index of
private")
Conclusion
The internet is a network to which hundreds of thousands, if not millions of web servers are connected
and in theory, all data can be reached, unless properly protected. Both software designers and end
users should pay more attention to default installation security configuration and security policy.
In the end, there are always going to be people who make mistakes, use default installs, use poorly
secured software or just don’t care or still believe there’s no danger in putting this kind of data online.
And in the end there’s also always going to be curious people who love to find that interesting
information they have been hoping for. Google can help you considerably, in locating this kind of
information and it’s easy and fun.
Sidenote
I have used in this article, “live examples” because “foobar examples” in this case wouldn’t have been
very useful. I hope you choose to learn from these examples and not use them to commit malicious
acts. Think of a great search string yourself and don’t abuse the ones I have shown to explain the
technique a little bit. (Guess I couldn’t stay away from the ethics lesson after all)
Afterword
To not abandon tradition I would like to take the chance to greet some people.
People like JLP, Rattlesnake, Drew, X, Tek, Sean, Marek, Resolution and others… you all know who
you are, Thanks for helping me out numerous times with numerous different things.
Bibliography
1. Google not 'hackers' best friend',James Middleton, VNUnet.com, 2001
http://www.vnunet.com/News/1127162
2. Google: Net Hacker Tool du Jour, Christopher Null, wired.com, 2003
http://www.wired.com/news/infostructure/0,1377,57897,00.html
3. Microsoft FrontPage 2000 Server Extensions Resource Kit
http://sciris.shu.edu/Manuals/FrontPage/serk/adhtm_1.htm
4. Hacking Exposed Third Edition, McClure, Scambray, Kurtz, ISBN: 0-07-219381-6
http://www.osborne.com