Cracking Passwords Version 0.5

August 5, 2008

Abstract

This document is for people who want to learn to the how and why of password cracking. There is a lot of information being presented and you should READ IT ALL BEFORE you attempted doing anything documented here. I do my best to provide step by step instructions along with the reasons for doing it this way. Other times I will point to a particular website where you find the information. In those cases someone else has done what I attempting and did a good or great job and I did not want to steal their hard work. These instructions have several excerpts from a combination of posts from pureh@te, granger53, irongeek, PrairieFire, RaginRob, stasik, and Solar Designer. I would also like to thank each of them and others for the help they have provided me on the BackTrack forum.

I will cover both getting the SAM from inside windows and from the BackTrack CD. The SAM is the Security Accounts Manager database where local usernames and passwords are stored. For legal purposes I am using my own system for this article. The first step is to get a copy of pwdump. You can choose one from http://en.wikipedia.org/wiki/Pwdump For these examples I will use pwdump7.exe. Update: I used to use pwdump7 to dump my passwords, however I have come across a new utility called fgdump from http://www.foofus.net/fizzgig/fgdump/ This new utility will dump passwords from clients and Active Directory (Windows 2000 and 2003 for sure, not sure about Windows 2008) where pwdump7 only dumps client passwords.

Contents

1 LM vs. NTLM
2 Dumping the SAM and cracking the password using BackTrack
   2.1 Dumping the SAM from inside BackTrack
   2.2 Cracking the LM hash using john the ripper
   2.3 Cracking the LM hash using mdcrack
   2.4 Cracking the NTLM hash using john the ripper
      2.4.1 Cracking the NTLM hash using the results from cracking the LM hash using john the ripper
   2.5 Cracking the NTLM hash using mdcrack
      2.5.1 Cracking the NTLM hash using the results from cracking the LM hash using mdcrack
   2.6 Cracking the LM hash using ophcrack
   2.7 Cracking the NTLM hash using ophcrack
3 Dumping the SAM and cracking the password using applications in Windows
   3.1 Dumping the SAM from windows
   3.2 Dumping Cached Credentials from windows
   3.3 Cracking the LM hash using john the ripper
   3.4 Cracking the LM hash using mdcrack
   3.5 Cracking the NTLM hash using john the ripper
   3.6 Cracking the NTLM hash using mdcrack
      3.6.1 Cracking the NTLM hash using the results from cracking the LM hash using mdcrack
   3.7 Cracking the LM hash using ophcrack (requires high speed internet access during install)
   3.8 Cracking the NTLM hash using ophcrack
   3.9 Cracking the LM and NTLM hash using Cain and Able
4 Cracking the LM and NTLM hashes using the ophcrack LiveCD
5 plain-text.info
6 Active Directory
7 Novell
8 Resetting a forgotten password on a local user account (NOT A DOMAIN ACCOUNT)
9 Cracking Linux/Unix passwords using John the Ripper
10 Cracking equipment passwords using Hydra in BackTrack
11 Cracking equipment passwords using Brutus in windows
12 Cracking Oracle 11g (sha1)
13 Cracking Oracle passwords over the wire
14 Syskey
15 Wordlists aka Dictionary attack
   15.1 Using John the Ripper to generate a wordlist
   15.2 Configuring John the Ripper to use a wordlist
   15.3 Using crunch to generate a wordlist
   15.4 Using premade wordlists
   15.5 Other wordlist generators
16 Rainbow Tables
   16.1 What are they?
   16.2 Generating your own
   16.3 WEP cracking
   16.4 WPA-PSK

1 LM vs. NTLM

The LM hash is the old style hash used in MS operating systems before NT 3.1. It converts the password to uppercase, null-pads or truncates the password to 14 characters. The password is split into two 7 character halves and uses the DES algorithm. NT 3.1 to XP SP2 supports LM hashes for backward compatibility and is enabled by default. Vista supports LM hashes but is disabled by default. Given the weaknesses in the LM hash it is recommended to disable using LM hashes for all MS operating systems using the steps in http://support.microsoft.com/kb/299656

NTLM was introduced in NT 3.1 and does not covert the password to uppercase, does not break the password apart, and supports password lengths greater than 14. There are two versions of NTLM v1 and v2. Do to a weakness in NTLM v1 is should not be used. Microsoft has included support for NTLM v2 for all of its operating systems either via service pack or the Directory Services client (for windows 9X). You enable NTLM v2 by following the instructions at http://support.microsoft.com/kb/239869. For maximum security you should set the LMCompatibility to 3 for Windows 9X and LMCompatibilityLevel to 5 for NT, 2000, XP, and 2003. Of course you should test these changes BEFORE you put them into a production environment.

If LM hashes are disabled on your system the output of pwdump will look like:

Administrator:500:NO PASSWORD*********************:00AB1D1285F410C30A83B435F2CA798D:::
Guest:501:NO PASSWORD*********************:31A6CAE0D36AD931B76C59D7E1C039C0:::
HelpAssistant:1000:NO PASSWORD*********************:BF23C2595478A6279F7CB53EF76E601F:::
SUPPORT_3845a0:1002:NO PASSWORD*********************:0C8D62E10A6240BACD910C8AB295BB79:::
ASPNET:1005:9F07AE96CA4310752BDC083AAC960496:A99C1C3DB39E3C732EF5C2F63579AF96:::

The first field is the username. The second field is the last four numbers of the SID for that username. The SID is a security identifier that is unique to each username. The third field is the LM hash. The forth field is the NTLM hash.

If you do not have a ASPNET user account do not worry about it. If you do have a ASPNET user account do NOT change the password as I am told that will break something. What I did was delete the account and then recreate it using: systemroot%\Microsoft.NET\Framework\v1.1.4322\aspnet_regiis.exe /i

2 Dumping the SAM and cracking the password using BackTrack

2.1 Dumping the SAM from inside BackTrack

  1. mount your windows partition substituting hda1 for whatever your windows partition is # mount /dev/hda1 /mnt/XXX
  2. if the syskey password is stored locally you need to extract it from the registry so you can decrypt the SAM. If syskey is setup to prompt for a password or the password is on a floppy, stop now and read the syskey documentation in this document for more information about syskey. If you installed windows to something other C:\WINDOWS please substitute the correct path. WARNING the path is case sensitive.

    BackTrack 2 users use the following:
    # bkhive-linux /mnt/XXX/WINDOWS/system32/config/system syskey.txt

    BackTrack 3 users use the following:
    # bkhive /mnt/XXX/WINDOWS/system32/config/system syskey.txt

  3. samdump2 will dump the SAM to the screen and the > character redirects the output to a file called hash.txt
    # samdump2 /mnt/XXX/WINDOWS/system32/config/sam syskey.txt >hash.txt

2.2 Cracking the LM hash using john the ripper

john only needs to know the path to the hash.txt to begin bruteforcing and return the uppercase password
# /usr/local/john/john hash.txt

2.3 Cracking the LM hash using mdcrack

  1. download mdcrack from http://membres.lycos.fr/mdcrack/ or http://c3rb3r.openwall.net/mdcrack/
  2. # mkdir mdcrack
  3. # mv MDCrack-183.zip mdcrack
  4. # unzip MDCrack-183.zip
  5. # wine MDCrack-sse.exe LMHASH
    LMHASH would be CEEB0FA9F240C200417EAF40CFAC29C3 for example
The result should be TESTTEST

2.4 Cracking the NTLM hash using john the ripper

john only needs to know the path to the hash.txt to begin cracking and return the uppercase password
# /usr/local/john/john -f:NT hash.txt
will begin to bruteforce the NTLM hashes

2.4.1 Cracking the NTLM hash using the results from cracking the LM hash using john the ripper

Stasik told me it is much easier to crack the NTLM hash if you know the character set. This way you do not need to bruteforce all possible characters combinations. Once you have TESTTEST, feed a custom character set of tesTES to john and it will return the proper case password much faster than if you did not limit the character set. The issue is john has no easy way to limit the character set. You will have to modify the john.conf file and include the following code that Solar Designer has kindly published to the john-users mail list:

[List.External:customcharset]
int running; // Are we already running?
int last; // Last character position, zero-based
int c0, c[0x100]; // Cyclic charset
void init()
{
   int length, cm, i;
   length = 10; // password length
   c[c0 = 't'] = 'e'; // change the t and the e to the first and second letters of the custom character set
   c['e'] = 's'; // change the e and the s to the second and third letters of the character set
   c['s'] = 'T'; // change the s and T to the third and fourth letters
   c['T'] = 'E'; // etc
   c['E'] = 'S'; // etc
   c[cm = 'S'] = c0; // change the S to the last letter of the character set

    // If you cannot see the pattern then do not bother with this trick.
   // If you can make the necessary changes to suit you environment.
   running = 0;
   last = length - 1;
   i = 0;
   while (i < length) word[i++] = cm; word[i] = 0;
}

void generate()
{
   int i;
   i = last;
   while ((word[i] = c[word[i]]) == c0)
      if (!i--) {
         if (running++) word = 0;
  &nbsp      return;
      }
}

Once you make the necessary changes begin cracking using:
# /usr/local/john/john -external=customcharset -f:NT hash.txt

Some notes from Solar Designer:

  1. Being an external mode, this is not the fastest way to generate candidate passwords, although its performance is acceptable. Some further optimizations are possible (e.g., cache the last character outside of the word[] array). Also, be careful when you edit it (such as for a different charset) - errors in the way the cyclic charset is defined may result in the "while" loop in generate() becoming endless.
  2. In order to actually crack an NTLM hash with this, you need a build of JtR with support for NTLM hashes. You may do a custom build with the latest jumbo patch (john-1.7.2-all-9.diff.gz), which means that you will need to install Cygwin on your Windows system, or you can download such a build made by someone else (one is linked from the JtR homepage - it is for an older version of the patch, though, so it is many times slower at NTLM hashes).
  3. On a modern system, with a recent jumbo patch, and with the proper "make" target for your system, this should complete its work against an NTLM hash (or against many such hashes) in just a few minutes.

2.5 Cracking the NTLM hash using mdcrack

  1. download mdcrack from http://membres.lycos.fr/mdcrack/ or http://c3rb3r.openwall.net/mdcrack/
  2. # mkdir mdcrack
  3. # mv MDCrack-183.zip mdcrack
  4. # unzip MDCrack-183.zip
  5. # wine MDCrack-sse.exe -algorithm=ntlm NTLMHASH
    NTLMHASH would be D280553F0103F2E643406517296E7582 for example
The result should be TestTest
The only way to speed up cracking is to know the length of the password and use -minsize= to specify it.

2.5.1 Cracking the NTLM hash using the results from cracking the LM hash using mdcrack

Stasik told me it is much easier to crack the NTLM hash if you know the character set. This way you do not need to bruteforce all possible characters combinations. Once you have TESTTEST, feed a custom character set of tesTES to mdcrack and it will return the proper case password much faster than if you did not limit the character set.

# wine MDCrack-sse.exe -charset=tesTES -algorithm=ntlm D280553F0103F2E643406517296E7582

If you know the password length you can use:

# wine MDCrack-sse.exe -charset=tesTES -algorithm=ntlm -minsize=8 -maxsize=8 D280553F0103F2E643406517296E7582

The password is TestTest however mdcrack 1.8.3 returns sestTest. I filed a bug report with Gregory Duchemin, the author of mdcrack, and he has fixed the problem with version 1.8.4.

2.6 Cracking the LM hash using ophcrack

download ophcrack from http://sourceforge.net/project/showfiles.php?group_id=133599 and download 1 of the 2 rainbow tables from http://lasecwww.epfl.ch/~oechslin/projects/ophcrack/. If you have the hard drive space I would recommend downloading SSTIC04-5K. If this is a demo or do not have a lot of disk space download SSTIC04-10K. This is not a typo; SSTIC04-5K is a larger download than SSTIC04-10K. The rainbow tables that ophcrack uses are NOT compatible with the rainbow tables generated by rtgen.

  1. # tar -xvzf ophcrack-2.4.1.tar.gz
  2. # cd ophcrack-2.4.1
  3. # ./configure
  4. # make
  5. # make install
  6. # ophcrack
  7. click on the load button and select the appropriate option, I will select local SAM.
  8. click on the tables button and select the rainbow table you installed.
  9. click on the launch button. You will see pre-loading table boxes on the screen. You may also see a message that says "All LM hashes are empty. Please use NThash tables to crack the remaining hashes." This means that the administrators have disabled windows ability to save LM hashes.
  10. wait until ophcrack is done

2.7 Cracking the NTLM hash using ophcrack

You will have to purchase the NTLM rainbow tables from http://www.objectif-securite.ch/en/products.php The rainbow table contains 99% of passwords of made of following characters:

length 1 to 6:
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$% &'()*+,-./:;&<=>?@[\]^_`{|}~ (space included)

length 7:
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

length 8:
0123456789abcdefghijklmnopqrstuvwxyz

You CANNOT generate your own rainbow tables for ophcrack to use. If you know that the password meets the above specs you can purchase the table and give it a try.

3 Dumping the SAM and cracking the password using applications in Windows

3.1 Dumping the SAM from windows

  1. Login to the system as an administrator and get to a command prompt (Start, Run, cmd). Since this my system I know administrator password. You could also try to use metasploit to attack your system to get to a command prompt.
  2. run the pwdump utility you downloaded

    C:\> pwdump7 >c:\hash.txt
    pwdump7 will dump the SAM to the screen and the > character redirects the output to a file called hash.txt

  3. copy the hash.txt file to a floppy or USB thumb drive if you are going to use BackTrack to crack the hashes

3.2 Dumping Cached Credentials from windows

When a user logs into a domain their password is cached in the registry so that in the event that the Domain Controller or network goes down the user can still login to their PC. To export these registry keys you need a tool call cachedump. It can be downloaded from http://www.mirrors.wiretapped.net/security/host-security/john/contrib/cachedump/
The readme.txt in the zip contains everything you want to know about where the cached credentials are stored, how cached credentials work, how they are hashed, and how the tool works.

You call also download the fgdump with source file from http://www.foofus.net/fizzgig/fgdump/ and get cachedump.

To use:

  1. Extract the cachedump.exe from the zip
  2. Login to the PC as an administrator
  3. Goto a cmd prompt (Start, Run, cmd)
  4. C:\> cd \path to cachedump.exe
  5. C:\> cachedump.exe -v
    This runs cachdump.exe in verbose mode. I suggest running cachedump in verbose the first time you use it so you know what is going on and can identify any problems. Once you have good information displayed on the screen you can use:
  6. C:\> cachedump.exe >cache.txt
    and this will redirect the output from the screen to a file called cache.txt

Now you can use john the ripper to crack the hashes. Please note that Cached Credentials use a different hash than LM or NTLM.

The best way to protect yourself from this is to disable cached credentials. Change the value of the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\WINLOGON\CACHEDLOGONSCOUNT to 0. You can do this manually or with Group Policy.

3.3 Cracking the LM hash using john the ripper

download john the ripper from http://www.openwall.com/john/

  1. open a command prompt (Start, Run, cmd, enter)
  2. cd to where you extracted john (I extracted john to the root of my C drive) so it would be cd \john171w\run

    C:\> cd \john171w\run

  3. john only needs to know the path to the hash.txt to begin bruteforcing and return the uppercase password

    C:\> john-386 C:\hash.txt

3.4 Cracking the LM hash using mdcrack

download mdcrack from http://membres.lycos.fr/mdcrack/ or c3rb3r.openwall.net/mdcrack/ and extract the files

  1. open a command prompt (Start, Run, cmd, enter)
  2. cd to where you extracted the files C:\> cd \mdcrack-183
  3. C:\MDCrack-183>MDCrack-sse.exe LMHASH
    LMHASH would be CEEB0FA9F240C200417EAF40CFAC29C3 for example
The result should be TESTTEST

3.5 Cracking the NTLM hash using john the ripper

You cannot as the john the ripper that you can download from the website does not support NTLM. You will have to download the source code, one of the patches that adds support for NTLM and compile it yourself. There are also one or two places where you can download a john binary that already has the patches applied.

3.6 Cracking the NTLM hash using mdcrack

download mdcrack from http://membres.lycos.fr/mdcrack/ or c3rb3r.openwall.net/mdcrack/ and extract the files

  1. open a command prompt (Start, Run, cmd, enter)
  2. cd to where you extracted the files C:\> cd \mdcrack-183
  3. C:\MDCrack-183> MDCrack-sse.exe -algorithm=ntlm NTLMHASH
    NTLMHASH would be D280553F0103F2E643406517296E7582 for example

The result should be TestTest

3.6.1 Cracking the NTLM hash using the results from cracking the LM hash using mdcrack

Stasik told me it is much easier to crack the NTLM hash if you know the character set. This way you do not need to bruteforce all possible characters combinations. Once you have TESTTEST, feed a custom character set of tesTES to mdcrack and it will return the proper case password much faster than if you did not limit the character set.

C:\MDCrack-183> MDCrack-sse.exe -charset=tesTES -algorithm=ntlm D280553F0103F2E643406517296E7582

If you know the password length you can use:

C:\MDCrack-183> MDCrack-sse.exe -charset=tesTES -algorithm=ntlm -minsize=8 -maxsize=8 D280553F0103F2E643406517296E7582

The password is TestTest

3.7 Cracking the LM hash using ophcrack (requires high speed internet access during install)

  1. download ophcrack from http://sourceforge.net/project/showfiles.php?group_id=133599
  2. start the installation and select next until you get to the Select Components screen. Select one of the two download options. If you have the hard drive space I would recommend downloading SSTIC04-5K. If this is for a demo or do not have a lot of disk space download SSTIC04-10K. This is not a typo; SSTIC04-5K is a larger download than SSTIC04-10K. Answer the rest of the install questions and click on install. The installer will start downloading the rainbow table you selected. The other options on the Select Components screen will cost you money as you have to purchase the DVD or CD. The rainbow tables that ophcrack uses are NOT compatible with the rainbow tables generated by rtgen.
  3. start ophcrack using the icon on the start menu bar.
  4. click on the load button and select the appropriate option, I will select local SAM.
  5. click on the tables button and select the rainbow table you installed.
  6. click on the launch button. You will see pre-loading table boxes on the screen. You may also see a message that says "All LM hashes are empty. Please use NThash tables to crack the remaining hashes." This means that the administrators have disabled windows ability to save LM hashes.
  7. wait until ophcrack is done

3.8 Cracking the NTLM hash using ophcrack

You will have to purchase the NTLM rainbow tables from http://www.objectif-securite.ch/en/products.php The rainbow table contains 99% of passwords of made of following characters:

length 1 to 6:
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$% &'()*+,-./:;&<=>?@[\]^_`{|}~ (space included)

length 7:
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

length 8:
0123456789abcdefghijklmnopqrstuvwxyz

You CANNOT generate your own rainbow tables for ophcrack to use. If you know that the password meets the above specs you can purchase the table and give it a try.

3.9 Cracking the LM and NTLM hash using Cain and Able

  1. Download Cain and Able from http://www.oxid.it/cain.html
  2. Install Cain and Able using the default settings
  3. Start Cain and Able
  4. Click on the Cracker tab
  5. Click somewhere inside the table
  6. Click on File, Add to list.
  7. Select Import hashes from local system and click next
  8. Right click on the account you want the password for and select Brute-force attack. Chose the option you want to use (for windows passwords either LM hashes or NTLM hashes).
  9. Select the character set you want to use, set the minimum and/or maximum password length if you know it to decrease the amount of cracking time needed.
  10. Click on Start and wait

4 Cracking the LM and NTLM hashes using the ophcrack LiveCD

The ophcrack LiveCD is good when you have physical access to the PC. Just download ophcrack-livecd from http://sourceforge.net/project/showfiles.php?group_id=133599, burn the iso to a CD, boot from the CD, and start cracking using the included SSTIC04-10K rainbow table. This will crack the LM hashes. To crack NTLM hashes you have to purchase 1 of the NTLM hash tables. See section 3.8 for details.

5 plain-text.info

The plain-text.info website is where you can take a LM or MD5 hash and see if someone has already cracked it. The website is easy to use and has a very large list of hashes for you to search. The website also has support for NTLM hashes, but none of the hashes I had were cracked there.

6 Active Directory

At the moment the pwdump7 utility only work on locally stored SAMs. It will not work on windows server 2000, 2003, or windows 2008 Active Directory. pwdump6 from http://www.foofus.net/fizzgig/pwdump/ can dump windows server 2000 and 2003 Active Directory to a file that john the ripper can crack. fgdump is a newer utility that can dump Active Directory and cached credentials.

See http://www.jms1.net/nt-unlock.shtml for resetting a windows 2000 domain account.
See http://www.nobodix.org/seb/win2003_adminpass.html for resetting a windows 2003 domain account.

7 Novell

If you have a windows client with the Novell NDS client installed you will notice that the client creates a local account on the PC. Usually the local password is the same as the NDS account password. By dumping the local SAM you can usually get a persons NDS password. The above trick I know works as I have used this once. The other techniques listed here I cannot say if they work or not as I retired the last Novell server several months ago.

I would recommend starting to read the documentation at http://www.nmrc.org/pub/faq/hackfaq/hackfaq-19.html to hackfaq-26.html for learning quite abit about attacking Novell servers v2.x to 4.x.

If you have access to the console and the floppy drive of the server you can try one of the console attacks from http://www.nmrc.org/pub/faq/hackfaq/hackfaq-21.html.

If all you have access to is a client you can try some of the client attacks from http://www.nmrc.org/pub/faq/hackfaq/hackfaq-22.html

If you don't have local administrator rights and your server is Novell you can watch the video at http://youtube.com/watch?v=GEl-CsUOY6A and get local administrator rights to your XP box. The attack is very simple you just have to pull your network cable at the right time.

You can use Pandora from http://www.nmrc.org/project/pandora/ to do online and offline attack againist Novell 4.x and 5.x servers.

From williamc's post at http://forums.remote-exploit.org/showpost.php?p=87491&postcount=7
"I confirmed an interesting vulnerability with Novell. According to this advisory, the Novell password can be dumped out of memory: http://www.securityfocus.com/archive/1/402767
We confirmed this on a Novell 7 environment while performing a pentest.
Use both Psexec and pmdump as follows:
psexec \\hostname -u username -p password -s -f -c pmdump -list

Find the PID of the Gwise.exe service. Then:
psexec \\hostname -u -p password -s -f -c pmdump PID PID_dump.txt

This will dump the memory to \\hostname\c$\windows\system32
Open the dump file in a hex editor and search for an organizational string, like an OU in the targets memory dump file.

From there you can find the Novell password for the user within the file.

To simplify this, if you have already found one Novell password, dump the PID for gwise of that user and search for the password. From there, you can work backwards to find the OU format, and apply it to other targets. For instance, at this particular location, the client's OU is similar to clientname.AA_FINANCE.AA_NW

If you do a search for AA_FINANCE.AA_NW in the memory dump you will see the password in plain text. Suppose the CFO is whomever.AA_FINANCE.AA_NW. By dumping his memory, you can search for the OU and reference your original dump, match up the location and password."

8 Resetting a forgotten password on a local user account (NOT A DOMAIN ACCOUNT)

chntpw is a part of BackTrack and can reset a forgotten local user account password. If you don't have BackTrack you can download a CD or floppy disk image from http://home.eunet.no/~pnordahl/ntpasswd/, unzip the file, and either burn the iso the to a CD or use rawrite2 to transfer the image to a floppy. Follow the directions at http://home.eunet.no/~pnordahl/ntpasswd/walkthrough.html on how to use the software.

9 Cracking Linux/Unix passwords using John the Ripper

Unix passwords are located in the /etc/shadow file or the /etc/passwd file. Next unix passwords are "shadowed" and we must "unshadow" them before we can do anything. Without getting into too much detail shadowing the passwords removes the passwords, which are usually stored in world readable /etc/passwd, and moves them to /etc/shadow which can only be read and written to by root or programs run as suid root. Goto http://www.tldp.org/HOWTO/Shadow-Password-HOWTO-2.html if you want details on how shadowing works. Finally unix passwords are salted. The short version is a salt is randomly generated value that is used to encode the user's password, which is usually already encrypted; thus adding another layer of security. The long version can be found at http://www.tldp.org/HOWTO/Shadow-Password-HOWTO-2.html

  1. boot the BackTrack cd and login as root
  2. # cd /usr/local/john
  3. # unshadow /etc/passwd /etc/shadow >saltedpasswords
    You have now written the unshadowed "salted" passwords to a file called saltedpasswords
  4. # john saltedpasswords

The above steps will crack the passwd file on the CD. If you want to crack a passwd file located on a hard drive:

  1. boot the BackTrack cd and login as root
  2. # mount /dev/hda1 /mnt/XXX
    mount your Linux partition substituting hda1 for whatever your Linux partition is
  3. # cd /usr/local/john
  4. # unshadow /mnt/XXX/etc/passwd /mnt/XXX/etc/shadow >saltedpasswords
  5. # john saltedpasswords

10 Cracking equipment passwords using hydra in BackTrack

Say you have wireless router to which you have forgotten the password. The easiest thing to do in this case is to reset the router to factory defaults. However if you have a lot of custom settings and your backup is nonexistent, out-dated, corrupted, or the backup restored a password which you do not remember, you can try a brute force attack on the router. From http://freeworld.thc.org/thc-hydra/ Hydra currently supports: TELNET, FTP, HTTP-GET, HTTP-HEAD, HTTPS-GET, HTTPS-HEAD, HTTP-PROXY, LDAP2, LADP3, SMB, SMBNT, MS-SQL, MYSQL, POSTGRES, REXEC, RSH, RLOGIN, CVS, SNMP, SMTP-AUTH, SOCKS5, VNC, POP3, IMAP, NNTP, PCNFS, ICQ, SAP/R3, SSH2, Teamspeak, Cisco auth, Cisco enable, Cisco AAA (incorporated in telnet module)

For the sake of this document I will use a Linksys WRT54GL, hardware v1.1, Linksys firmware 4.30.11. The first thing you have to do is find out if the device uses a username AND password to login. Several devices only require a password to login into the device as admin, root, system, etc. The easiest way to find this out is to goto the vendor's website and download installation manual which will give you this information.

  1. boot the BackTrack cd and login as root
  2. hydra -l "" -P word.txt -f -v -e ns 192.168.1.1 http-get /
    -l is for a username which is null in this case
    -P is a wordlist of passwords to try
    -f stop hydra when it finds the password
    -v is for verbose
    -e try no password and password the ip address of the device one of the currently supported options
    192.168.1.1 is the IP of the AP
    http-get is the correct option to this AP
    / is where you have to put in the username and password. In this case you have to put in the username and password before you can do anything. You will have to figure this out for yourself as each device is different.

As I said earlier, http-get is the correct option for my linksys AP (with the factory firmware). When you goto the AP website a dialog box opens and prompts for a username and password. Each AP is different and as such you will have to change options as RaginRob found out. The following is a slightly modified version from his tutorial at http://forums.remote-exploit.org/showthread.php?t=14910

I recently started playing around with Hydra and tried to hack my router. After searching the forum and googleing around a while I noticed that there are only some howto's for routers that have http-auth authentication. That is, when you go to 192.168.2.1 e.g. and before showing anything you have to enter login and password in a popup. My router (T-Com Sinus 154 DSL Basic 3) and many others I've dealt with so far work differently. When I want to login to my router, I have to go to 192.168.2.1, a web interface with a password field shows up, and I have to enter the password which is then checked by /cgi-bin/login.exe via http-post.

It was quite tricky to find out how to use this authentication with hydra, so I guess there are some of you that can benefit from this. I'll describe how I did it, so you can adapt the method and use it with your own router.

First of all I examined the login page of the web interface. Be sure to look at the frame source and not the frameset. You should see the form and the action, here's what I saw:

The form is defined as:
<form name="tF" method="post" action="/cgi-bin/login.exe" onSubmit="evaltF();">

Somewhere in the form there will be the field that takes the password:
<input type="password" name="pws" class="stylepwd" size="12" maxlength="12">

This is probably the most important data you need. You need to write down the field name ("pws" in my case). The size attribute comes in very handy too because it tells us that the password's max length is 12 characters.

After that I tried to get familiar with Hydra's options. I figured out that you need the following options:

hydra -l "" -P passwords.txt -t 1 -f -v -V 192.168.2.1 http-post-form /cgi-bin/login.exe:pws=^PASS^:loginpserr.htm
-l Sets the login name. In the end I don't need a login name but hydra gets kind of pissed when you don't pass something, so I gave an empty string.
-P The wordlist to use for the password
-t 1 task only, not really neccesary, I just wanted to make sure Hydra doesn't choke on too many requests -f Hydra shall stop when a working password is found
-v be verbose. and even more. I skipped that in the final version but it's ok for debugging
192.168.1.1 is victim's ip
http-post-form the method to use
/cgi-bin/login.exe:pws=^PASS^:loginpserr.htm
This is the most important part. Here we tell Hydra what to pass the passwords to. The argument consists of three parts separated by ":".

The first part is the script that takes the POST data, we found that in the frame source above.

The second part is the field name of the password field with an added =^PASS^. ^PASS^ is the variable that hydra substitutes with the passwords in the wordlist.

The third part is the "incorrect" condition. Hydra has to find out somehow if the current password that was send to the router is correct or not. You have to find a string that is actually IN A NEGATIVE RESPONSE from the router. As we don't have the password yet we can't know what the router will send if the password is correct, therefore we have to check if it is NOT, which we can find out easily. To find out what the router sends back to hydra I used Wireshark.

Open up wireshark, go to the router login page, start capturing and then login with a wrong password. After that, stop capturing and apply a "http" filter. You will see the POST data sent from hydra to the router (you should also see the "pws=blabla" in the details, that's where hydra sends the passwords from the wordlist). Below that you'll find the router answer. In my case it says something like "This page has moved to loginpserr.htm" packed in some basic HTML. So I used the string loginpserr.htm to validate the .. uhm... faultyness. OMFG %-]

Hydra will consider a password as CORRECT when the router answer DOES NOT contain the given string. So be sure to take an expression that somehow sounds like "incorrect" oder "wrong". If you took "the" for example, and the POSITVE response would be something like "the password you entered was correct", hydra will not recognize it as correct but incorrect.

If your router does not only need a password but also a username, you can easily add the according login name to the last part. So if you need to send the field "login" or whatever it is called in your case with the value "admin" as the only username you could use

/cgi-bin/login.exe:login=admin&pws=^PASS^:loginpserr.htm

When you need to try a whole username list then you can specify the list via
-L usernames.txt
and
/cgi-bin/login.exe:login=^USER^&pws=^PASS^:loginpserr.htm

11 Cracking equipment passwords using Brutus in windows

Brutus is a windows application that does things similar to Hydra. You can find it at http://www.hoobie.net/brutus/

12 Cracking Oracle 11g (sha1)

I cannot do any better than sending you to freeworld.thc.org/thc-orakelcrackert11g/

13 Cracking Oracle passwords over the wire

Again The Hacker's Choice at http://freeworld.thc.org/thc-orakel/ has great documentation on this

14 Syskey

To make it more difficult to crack your passwords, use syskey. For more information on syskey see http://support.microsoft.com/kb/310105. The short version is syskey encrypts the SAM. The weakest option but most convenient is to store a system generated password locally; locally means the registry. The up side is the SAM gets encrypted and you can reboot the server remotely without extra equipment. The next option is password startup. This is slightly more difficult to get around, but if you remotely reboot the server, it will stop and wait for someone to enter the password. You will need a KVM over IP or a serial port concentrator so you can enter the password remotely. The most secure option is the system generated password stored on a floppy disk. The downside to this option is floppy disks fail, you misplace the floppy disk, newer equipment does not have a floppy disk drive, no remote reboots, and you will probably leave the floppy in the drive so you can remote reboot and that defeats security. I use a system generated password stored locally, weak but better than not doing it. To disable syskey use chntpw and follow its instructions.

15 Wordlists aka Dictionary attack

Strictly speaking a wordlist is a file that contains words or phrases from everyday life. The premade files below are wordlists. The other instructions in this section are not really wordlists as the resulting file every possible combination (depending on the options you give the program) of characters. I have not come across a word to describe these files so I am naming a file that contains every possible combination of characters a combination list. Not very original but it does clearly differentiate between the two types of lists. The resulting combination list can be used in place of a wordlist. Please note that when you generate a combination list the file will be huge. Using the 95 English characters to generate every possible combination of 10 characters the resulting file size will be 95^10 =
59,873,693,923,837,900,000 bytes
59,873,693,923,837,900 KB
59,873,693,923,838 MB
59,873,693,924 GB
59,873,694 TB
59,874 PB
60 EB

For 14 characters the file size would be 4,877 YB

The following is cut and paste from http://freeworld.thc.org/thc-hydra/README

"* uniq your dictionary files! this can save you a lot of time :-)
cat words.txt | sort | uniq > dictionary.txt

* if you know that the target is using a password policy (allowing users only to choose password with a minimum length of 6, containing a least one letter and one number, etc. use the tool pw-inspector which comes along with the hydra package to reduce the password list:
cat dictionary.txt | pw-inspector -m 6 -c 2 -n > passlist.txt"

The above paragraph is true for any wordlist and very good advice. See http://forums.remote-exploit.org/showthread.php?t=7199 for places to download wordlists. Remember you want as many possible words as you can fit on your storage device. More is better as long as the list only contains unique words.

15.1 Using John the Ripper to generate a wordlist

For Windows use:
C:\john\john-386.exe --stdout --incremental >wordlist.txt

For Linux use:
#/usr/local/john/john --stdout --incremental >wordlist.txt

The resulting output will be written to the wordlist.txt file.

If you know the maximum length of the password you can use --stdout=length and john output passwords of that length or less. For example --stdout=5 will generate words that are 5 characters long or shorter. Please note that the maximum length john supports by default is 8. If you need to generate a 9 character or longer wordlist you will have to download the source and change a line or two of code. Or you can use a different tool.

15.2 Configuring John the Ripper to use a wordlist

If you have a wordlist (wordlist.txt) you want to try against NTLM hashes use the following command:

john -f:NT -w:wordlist.txt pwhashes.txt

or you can edit the john.conf file to use your wordlist. So it would look like this:

[Options]
# Wordlist file name, to be used in batch mode
Wordlist = $JOHN/wordlist.txt
# Use idle cycles only
Idle = N
# Crash recovery file saving delay in seconds
Save = 600
# Beep when a password is found (who needs this anyway?)
Beep = N

15.3 Using crunch to generate a wordlist

in /pentest/password/crunch run it with a --help to see the options. It will ask for a minimum length, maximum length, character set etc.

15.4 Using premade wordlists

Xploitz and pureh@te have released their wordlists. The first two are torrents; the rest can be downloaded from the URL.

pureh@te's wordlist - http://www.h33t.com/details.php?id=178f55c67ca0f522831dbc67042a34983e6652f5

Xploitz's first wordlist - http://thepiratebay.org/tor/4017231

Xploitz's second wordlist part 1 - http://www.mediafire.com/?am2exxlnwma
Xploitz's second wordlist part 2 - http://www.mediafire.com/?4mzmdsbhhcn
Xploitz's second wordlist part 3 - http://www.mediafire.com/?4v9znjscgwt
Xploitz's second wordlist part 4 - http://www.mediafire.com/?dmj6yy3gw3x
Xploitz's second wordlist part 5 - http://www.mediafire.com/?5tyidngmztx
Xploitz's second wordlist part 6 - http://www.mediafire.com/?3utzg3jk1mb
Xploitz's second wordlist part 7 - http://www.mediafire.com/?dmwdvdrgsgb

Pureh@te has released another wordlist. It is 64 million words 8-63 characters and it was made from his other wordlist.
http://www.megaupload.com/?d=7RN6ZB2E

15.5 Other wordlist generators

You could try the wg perl script from http://freshmeat.net/projects/wg/
$ perl ./wg.pl -l 8 -u 64 -v abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789\`\~\!\@\#\$\%\^\&\*\(\)\-\_\+\=\[\]\;\'\,\.\/\<\>\?\:\"\{\}\|\ > words.txt

This will generate a list of "words" (actually character strings) between 8 and 64 characters long (-l 8 -u 64) and output it to a text file named "words.txt". The \ characters are there to escape the bash command characters.

Siph0n has taken a C program a thread, converted it to python, and made a couple of enhancements. You can download the source from http://forums.remote-exploit.org/showthread.php?t=14204

NOTE: When generating your own wordlists keep in mind that some programs (aircrack-ng) have a 2GB file size limit. There is also the issue of RAM. If you can keep the entire wordlist in RAM, the cracking will proceed that much faster. So keep your wordlists to a maximum of 2GB. If you have a wordlist that is larger than you want it to be and/or you want to use aircrack-ng you will have to do:
# split -bytes=1024 m /tmp/dictionay_file_3GB /tmp/smaller_dictionary_file
please subsitute 1024 m for whatever filesize you wish and change /tmp/ to the proper path you want to use.

16 Rainbow Tables

16.1 What are they?

Rainbow tables are files that contain pre-computed hashes of passwords. This drastically cuts down on the time it takes to crack passwords. You will need a set of tables for each algorithm you want to break. Since LM hashes are so weak I do not waste the disk space to store them. The last time I checked the size of the LM hash rainbow tables for a password of 1 to 7 characters and a character set of:

[ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_+=~`[]{}|\:;"'<>,.?/] was 120GB in size. The table was generated by Hak5. This table is supposed to have a 99.9% success rate. You do not need a table with 8 to 14 characters as the password is split into 2 separate 7 character hashes.

NTLM tables are larger as the possible character set is:

[abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_+=~`[]{}|\:;"'<>,.?/] and the password is not broken into smaller parts. Given this and most likely you have 6 or 7 character minimum password length; the size of the tables can be quite large. I have not found anywhere to download a reasonable set of NTLM rainbow tables. To me reasonable is from 1 to 14 characters using the above character set. A table using these specs will extremely large.

16.2 Generating your own

To generate you rainbow tables you need three things: what algorithm are you going to need, the software to generate the table, a really fast PC or FPGA or GPU. Let us start with the NTLM algorithm. The BackTrack software has rtgen available to generate the tables. If you want to generate tables using windows download Cain & Abel from http://www.oxid.it/projects.html as that contains the latest release of winrtgen.

A set of tables that use the loweralpha-numeric-symbol14 character set for a maximum of 8 character password and a 99.6972% probability of success will take 120 tables and 175GB of disk space. I used winrtgen to get these figures. To begin the generation:

boot the BackTrack cd and login as root

# rtgen ntlm loweralpha-numeric-symbol14 1 8 0 20000 97505489 _XXX
rtgen is application
ntlm is the algorithm you want to rtgen to use
loweralpha-numeric-symbol14 is the character set you want to use
1 is the minimum password length
8 is the maximum password length
0 is the table index - do not worry about it
20000 is the chain length, higher numbers increase the probability success rate without increasing the table size much
97505489 is the number of chains to store in the table. Think of this as the size of table you want to generate. 97505489 is the right size to generate a table if you are going to store them on a DVD. With 97505489 you can store 3 tables on 1 DVD. Use 40000000 if you are to store the table on a CD. You can use whatever number you want as long as the resulting table is less than 2GB in size. The password cracking tools have issues with tables greater than 2GB.
_XXX is whatever you want appended to the filename. Since I know I need 120 tables I will start with _001 and end at _120

So to generate 3 tables you do:
# rtgen ntlm loweralpha-numeric-symbol14 1 8 0 20000 97505489 _001
# rtgen ntlm loweralpha-numeric-symbol14 1 8 0 20000 97505489 _002
# rtgen ntlm loweralpha-numeric-symbol14 1 8 0 20000 97505489 _003

which will result in the following files be created:
ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_001.rt
ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_002.rt
ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_003.rt

Once all of the tables have been generated you have to sort them before you can use them:
# rtsort ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_001.rt
# rtsort ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_002.rt
# rtsort ntlm_loweralpha-numeric-symbol14#1-8_0_20000x97505489_003.rt

Each command will take awhile to complete. The larger the file the longer it takes. It is recommended that you do this on a PC with at least 2GB of RAM (if you use 97505489 as the number of chains) so the entire file can be loaded into RAM which makes the sort faster.

16.3 WEP cracking

You do not need rainbow tables for WEP. See other postings for WEP cracking details.

16.4 WPA-PSK

Rainbow tables can be used to crack the Pre-Shared Keyes of WPA. The Church of WIFI has a 40GB torrent of rainbow tables that use ~1,000,000 words for a total of approximately 40GB of hash tables for the top 1000 SSID's. The torrent is at http://umbra.shmoo.com:6969/torrents/wpa_psk-h1kari_renderman.torrent

Changes from version 0.1

Changes from version 0.2

Changes from version 0.3

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