Zip file password cracker python script

Today we will understand python script to crack specific zip file password by dictionary attack.Python has inbuilt module for zip file which we import at starting of script; then we import optparse ,this allow user to specify user to zip file & dictionary file.Then import threading this allow simultaneous testing of multiple passwords from dictionary.

#!/usr/bin/python
import zipfile
import optparse
from threading import Thread

def extractFile(zFile, password):
try:
zFile.extractall(pwd=password)
print ‘[+] Found password ‘ + password + ‘\n’
except:
pass

def main():
parser = optparse.OptionParser(“usage %prog “+\
“-f -d “)
parser.add_option(‘-f’, dest=’zname’, type=’string’,\
help=’specify zip file’)
parser.add_option(‘-d’, dest=’dname’, type=’string’,\
help=’specify dictionary file’)
(options, args) = parser.parse_args()
if (options.zname == None) | (options.dname == None):
print parser.usage
exit(0)
else:
zname = options.zname
dname = options.dname

zFile = zipfile.ZipFile(zname)
passFile = open(dname)

for line in passFile.readlines():
password = line.strip(‘\n’)
t = Thread(target=extractFile, args=(zFile, password))
t.start()

if __name__ == ‘__main__’:
main()

As usual there is two function(1)main(2)extractfile

(1)main() :-
parser = optparse.OptionParser(“usage %prog “+\ “-f -d “)
Above line display usage option on terminal screen.

parser.add_option(‘-f’, dest=’zname’, type=’string’,\ help=’specify zip file’)
Individual command line option to specify zip file name ;so when we execute script we have to provide -f before zip file name.

parser.add_option(‘-d’, dest=’dname’, type=’string’,\ help=’specify dictionary file’)
Individual command line option to specify dictionary file ;so when we execute script we has to prode -d before dictionary file name.

After that there is if loop which check that if there is invalid zip file or invalid dictionary file name then it print usage message & exit execution.And if zip file name & dictionary file is valid then it saved it name to variable zname & dname.

zFile = zipfile.ZipFile(zname) : It indicate that we instantiate new zip file class by specifying file name of password protected zip file.

passFile = open(dname) :- Open the dictionary file & saved it to passFile.

for line in passFile.readlines(): This loop is executed for number of words in dictionary file.
First read lines from dictionary file ;save string to line ;then strip dictionary one by one word & saved value of word to password.

Now we call extractfile function

(2)extractFile(zFile, password):
zFile.extractall(pwd=password) :- It extract zip file with password from variable password which come from for loop & which is first word of dictionary file, if password is true than it print Found password with password.

Now if password is wrong it threw error message. & for loop is again executed from main function & now password is second word of dictionary file.

zip-file-password-crack

Usage:-
chmod +x script_name
./script_name -f zip_file_name -d dictionary_file_name