After seeing how to compile John the Ripper to use all your computer's processors now we can use it for some tasks that may be useful to digital forensic investigators: getting around passwords. Today we will focus on cracking passwords for ZIP and RAR archive files. Luckily, the JtR community has done most of the hard work for us. For this to work you need to have built the community version of John the Ripper since it has extra utilities for ZIP and RAR files.
Using default input encoding: UTF-8 Loaded 1 password hash (Raw-SHA256 SHA256 128/128 SSE2 4x) Press 'q' or Ctrl-C to abort, almost any other key for status 0g 0:00:00:06 DONE (2017-01-06 12:47) 0g/s 2347Kp/s 2347Kc/s 2347KC/s Session completed show $ john -show mypassword 0 password hashes cracked, 1 left What did I do wrong? Type rtgen sha1 ascii-32-95 1 20 0 1000 1000 0 and press Enter (creates a sha1 rainbow crack table) 4. Press Enter (sort Rainbow) 5.l /root/capturedhashes.txt and press Enter to crack the password in hash file.h hashvalue and press Enter to crack the password in hash 7. Answer Questions.
For this exercise I have created password protected RAR and ZIP files, that each contain two files.The password for the rar file is 'test1234' and the password for the zip file is 'test4321'.
John The Ripper Crack Hashes
- John the Ripper is a widely known and verified fast password cracker, available for Windows, DOS, BeOS, and OpenVMS and many flavours of Linux. It uses wordlists/dictionary to crack many different types of hashes including MD5, SHA, etc. John the Ripper: Fast Password Cracker.
- John the Ripper is a favourite password cracking tool of many pentesters. There is plenty of documentation about its command line options. I’ve encountered the following problems using John the Ripper. These are not problems with the tool itself, but inherent problems with pentesting and password cracking in general.
In the 'run' folder of John the Ripper community version (I am using John-1.7.9-jumbo-7), there are two programs called 'zip2john' and 'rar2john'. Run them against their respective file types to extract the password hashes:
This will give you files that contain the password hashes to be cracked... something like this:
After, that you can run John the Ripper directly on the password hash files:
You should get a message like:
Loaded 1 password hash (PKZIP [32/64])
. By using John with no options it will use its default order of cracking modes. See the examples page for more information on modes.Notice, in this case we are not using explicit dictionaries. You could potentially speed the cracking process up if you have an idea what the password may be. If you look at your processor usage, if only one is maxed out, then you did not enable OpenMP when building. If you have a multi-processor system, it will greatly speed up the cracking process.
Now sit back and wait for the cracking to finish. On a 64bit quad-core i7 system, without using GPU, and while doing some other CPU-intensive tasks, the password was cracked in 6.5 hours.
Now if you want to see the cracked passwords give john the following arguments: It should output something like:
John The Ripper 0 Password Hashes Cracked 1 Left Handed
Note: the hash file should have the same type of hashes. For example, we cannot put the rar AND zip hashes in the same file. But this means you could try to crack more than one zip/rar file at a time.For the rar file it did not take nearly as long since the password was relatively common. If you take a look at john.conf in the run directory, it has a list of the patterns it checks (in order). The pattern 12345 is much more likely than 54321, so it is checked first resulting in a quick crack.