18 March 2010
Cracking Zip Password Files !!
Cracking Zip Password Files !!
I will do by using FZC ..
What is FZC?
FZC is a program that cracks zip files (zip is a method of compressing multiple
files into one smaller file) that are password-protected (which means you're
gonna need a password to open the zip file and extract files out of it). You can
get it anywhere - just use a search engine such as altavista.com.
FZC uses multiple methods of cracking - bruteforce (guessing passwords
systematically until the program gets it) or wordlist attacks (otherwise known
as dictionary attacks. Instead of just guessing passwords systematically, the
program takes passwords out of a "wordlist", which is a text file that contains
possible passwords. You can get lots of wordlists at www.theargon.com.).
FZC can be used in order to achieve two different goals: you can either use it
to recover a lost zip password which you used to remember but somehow forgot, or
to crack zip passwords which you're not supposed to have. So like every tool,
this one can be used for good and for evil.
The first thing I want to say is that reading this tutorial... is the easy way
to learn how to use this program, but after reading this part of how to use the
FZC you should go and check the texts that come with that program and read them
all. You are also going to see the phrase "check name.txt" often in this text.
These files should be in FZC's directory. They contain more information about
FZC.
FZC is a good password recovery tool, because it's very fast and also support
resuming so you don't have to keep the computer turned on until you get the
password, like it used to be some years ago with older cracking programs. You
would probably always get the password unless the password is longer than 32
chars (a char is a character, which can be anything - a number, a lowercase or
undercase letter or a symbol such as ! or &) because 32 chars is the maximum
value that FZC will accept, but it doesn't really matter, because in order to
bruteforce a password with 32 chars you'll need to be at least
immortal..heehhe.. to see the time that FZC takes with bruteforce just open the
Bforce.txt file, which contains such information.
FZC supports brute-force attacks, as well as wordlist attacks. While brute-force
attacks don't require you to have anything, wordlist attacks require you to have
wordlists, which you can get from www.theargon.com. There are wordlists in
various languages, various topics or just miscellaneous wordlists. The bigger
the wordlist is, the more chances you have to crack the password.
Now that you have a good wordlist, just get FZC working on the locked zip file
We need to keep in mind that are some people might choose some really weird
passwords (for example: 'e8t7@$^%*gfh), which are harder to crack and are
certainly impossible to crack (unless you have some weird wordlist). If you have
a bad luck and you got such a file, having a 200MB list won't help you anymore.
Instead, you'll have to use a different type of attack. If you are a person that
gives up at the first sign of failure, stop being like that or you won't get
anywhere. What you need to do in such a situation is to put aside your sweet xxx
MB's list and start using the Brute Force attack.
If you have some sort of a really fast and new computer and you're afraid that
you won't be able to use your computer's power to the fullest because the zip
cracker doesn't support this kind of technology, it's your lucky day! FZC has
multiple settings for all sorts of hardware, and will automatically select the
best method.
Now that we've gone through all the theoretical stuff, let's get to the actual
commands.
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Bruteforce
--------------------------------------------------------------------------------
The command line you'll need to use for using brute force is:
fzc -mb -nzFile.zip -lChr Lenght -cType of chars
Now if you read the bforce.txt that comes with fzc you'll find the description
of how works Chr Lenght and the Type of chars, but hey, I'm gonna explain this
too. Why not, right?... (but remember look at the bforce.txt too)
For Chr Lenght you can use 4 kind of switches...
-> You can use range -> 4-6 :it would brute force from 4 Chr passwors to 6 chr
passwords
-> You can use just one lenght -> 5 :it would just brute force using passwords
with 5 chars
-> You can use also the all number -> 0 :it would start brute forcing from
passwords with lenght 0 to lenght 32, even if you are crazy i don't think that
you would do this.... if you are thinking in doing this get a live...
-> You can use the + sign with a number -> 3+ :in this case it would brute force
from passwords with lenght 3 to passwords with 32 chars of lenght, almost like
the last option...
For the Type of chars we have 5 switches they are:
-> a for using lowercase letters
-> A for using uppercase letters
-> ! for using simbols (check the Bforce.txt if you want to see what simbols)
-> s for using space
-> 1 for using numbers
Example:
If you want to find a password with lowercase and numbers by brute force you
would just do something like:
fzc -mb -nzTest.zip -l4-7 -ca1
This would try all combinations from passwords with 4 chars of lenght till 7
chars, but just using numbers and lowercase.
*****
hint
*****
You should never start the first brute force attack to a file using all the
chars switches, first just try lowercase, then uppercase, then uppercase with
number then lowercase with numbers, just do like this because you can get lucky
and find the password much faster, if this doesn't work just prepare your brain
and start with a brute force that would take a lot of time. With a combination
like lowercase, uppercase, special chars and numbers.
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Wordlis
--------------------------------------------------------------------------------
Like I said in the bottom and like you should be thinking now, the wordlist is
the most powerfull mode in this program. Using this mode, you can choose between
3 modes, where each one do some changes to the text that is in the wordlist, I'm
not going to say what each mode does to the words, for knowing that just check
the file wlist.txt, the only thing I'm going to tell you is that the best mode
to get passwords is mode 3, but it takes longer time too.
To start a wordlist attak you'll do something like.
fzc -mwMode number -nzFile.zip -nwWordlist
Where:
Mode number is 1, 2 or 3 just check wlist.txt to see the changes in each mode.
File.zip is the filename and Wordlist is the name of the wordlist that you want
to use. Remember that if the file or the wordlist isn't in the same directory of
FZC you'll need to give the all path.
You can add other switches to that line like -fLine where you define in which
line will FZC start reading, and the -lChar Length where it will just be read
the words in that char length, the switche works like in bruteforce mode.
So if you something like
fzc -mw1 -nztest.zip -nwMywordlist.txt -f50 -l9+
FZC would just start reading at line 50 and would just read with length >= to 9.
Example:
If you want to crack a file called myfile.zip using the
"theargonlistserver1.txt" wordlist, selecting mode 3, and you wanted FZC to
start reading at line 50 you would do:
fzc -mw3 -nzmyfile.zip -nwtheargonlistserver1.txt -f50
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Resuming
--------------------------------------------------------------------------------
Other good feature in FZC is that FZC supports resuming. If you need to shutdown
your computer and FZC is running you just need to press the ESC key, and fzc
will stop. Now if you are using a brute force attack the current status will be
saved in a file called resume.fzc but if you are using a wordlist it will say to
you in what line it ended (you can find the line in the file fzc.log too).
To resume the bruteforce attack you just need to do:
fzc -mr
And the bruteforce attack will start from the place where it stopped when you
pressed the ESC key.
But if you want to resume a wordlist attack you'll need to start a new wordlist
attack, saying where it's gonna start. So if you ended the attack to the
file.zip in line 100 using wordlist.txt in mode 3 to resume you'll type
fzc -mw3 -nzfile.zip -nwwordlist.txt -f100
Doing this FZC would start in line 100, since the others 99 lines where already
checked in an earlier FZC session.
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