Howto Crack Zip Files Password
Posted by admin on April 12th, 2008 
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Install fcrackzip in Ubuntu
sudo aptitude install fcrackzip
This will complete the installation.
Fcrack Syntax
fcrackzip [-bDBchVvplum2] [--brute-force] [--dictionary] [--benchmark] [--charset characterset] [--help] [--validate] [--verbose] [--init-password string/path] [--length min-max] [--use-unzip] [--method name] [--modulo r/m] file.
fcrack Options
-h, –help
Prints the version number and (hopefully) some helpful insights.
-v, –verbose
Each -v makes the program more verbose.
-b, –brute-force
Select brute force mode. This tries all possible combinations of the letters you specify.
-D, –dictionary
Select dictionary mode. In this mode, fcrackzip will read passwords from a file, which must contain one password per line and should be alphabetically sorted (e.g. using (1)).
-c, –charset characterset-specification
Select the characters to use in brute-force cracking. Must be one of
a include all lowercase characters [a-z]
A include all uppercase characters [A-Z]
1 include the digits [0-9]
! include [!:$%&/()=?[]+*~#]
: the following characters upto the end of the spe-
cification string are included in the character set.
This way you can include any character except binary
null (at least under unix).
For example, a1:$% selects lowercase characters, digits and the dollar and percent signs.
-p, –init-password string
Set initial (starting) password for brute-force searching to string, or use the file with the name string to supply passwords for dictionary searching.
-l, –length min[-max]
Use an initial password of length min, and check all passwords upto passwords of length max (including). You can omit the max parameter.
-u, –use-unzip
Try to decompress the first file by calling unzip with the guessed password. This weeds out false positives when not enough files have been given.
-m, –method name
Use method number “name” instead of the default cracking method. The switch –help will print a list of available methods. Use –benchmark to see which method does perform best on your machine. The name can also be the number of the method to use.
-2, –modulo r/m
Calculate only r/m of the password. Not yet supported.
-B, –benchmark
Make a small benchmark, the output is nearly meaningless.
-V, –validate
Make some basic checks wether the cracker works.
fcrackzip Examples
fcrackzip -c a -p aaaaaa sample.zip
checks the encrypted files in sample.zip for all lowercase 6 character passwords (aaaaaa … abaaba … ghfgrg … zzzzzz).
fcrackzip --method cpmask --charset A --init AAAA test.ppm
checks the obscured image test.ppm for all four character passwords. -TP fcrackzip -D -p passwords.txt sample.zip check for every password listed in the file passwords.txt.
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April 12th, 2008 at 1:46 pm
sounds great!
I’m still looking for a rar cracker though
April 14th, 2008 at 3:07 am
I’m also looking for a RAR cracker that runs under Linux
June 8th, 2008 at 3:18 pm
Should be made multi-threading to take advantage of todays CPUs, I’ve got a quad core CPU and only one core works 100% when fcrackzip is running.
June 30th, 2008 at 5:05 pm
@Martin:
If you run fcrackzip 4 times simultaneously (each on a different core) with the starting passwords spaced out about equally and stop the other 3 when one finds the right pass, then that should work about the same as you describe.
Ex (modified from the one in the article):
fcrackzip --method cpmask --charset A1 --init 0000 test.ppmon the first core…
fcrackzip --method cpmask --charset A1 --init 9000 test.ppmon the second core…
fcrackzip --method cpmask --charset A1 --init I000 test.ppmon the third core, and…
fcrackzip --method cpmask --charset A1 --init R000 test.ppmon the fourth CPU
I don’t know how to control which CPU handles which copy of fcrackzip because I’ve never had a computer new enough to have multiple cores (I’m posting from a used Compaq Armada M700 circa 2001 with a 1GHz PIII), but I don’t see why this wouldn’t work.