cRARk 3.43

Overview

Since you’re reading this, I’m assuming you a) want to find the password of a locked RAR archive or b) landed here by mistake. In case of b), there’s no reason to stay here so perhaps you want to visit this site and improve your vocabulary skills while participating in a good cause: http://freerice.com/. If on the other hand you have a locked RAR file and want to open it, then a command-line tool called cRaRk will help you achieve this by using brute-force attack. This type of attack goes through all possible combinations of characters until it finds the correct one; it’s handy for small passwords, but chances are that this method won’t get you anywhere for longer and more complicated passwords.

Installation

No installation needed here, but you do have to make a few configurations first before you can use the program. After downloading the archive that contains cRaRk, extract its contents. The last item that is going to be extracted is password protected, so skip that one (it’s used for testing purposes). Among the extracted contents are three files that you need: “english.def”, “spanish.def” and “russian.def”. Depending on your language, change the appropriate file’s name to “password.def”. Therefore English-speaking users will rename “english.def” to “password.def”. This is the first and most basic setting you’ll have to make, but you may have to change other things as well for more specific usage of the program. For more information on this part, read section 4.2 of the F.A.Q. page: http://www.crark.net/cRARk.html#4.

In the same directory there’s also a file called “driver-timeout.reg”. Windows Vista and 7 users might need to import it into the registry (double click on it) if a message about stopped driver appears while using cRaRk.

This software is available for Windows, Mac OS X and Linux.

Interface

The program is used via the command-line interface, so don’t expect a GUI or anything. For help on how to use the program, launch crark.exe. The command-line window will open with information on the program’s usage and the arguments you can use.

If however you’re not a fan of command-line tools, then Crark GUI wrapper for Windows will make your day, but keep in mind that it was not designed by cRaRk’s author.

Pros

To perform the password recovery operation, cRaRk uses a password definition file which contains all the rules that cRaRk is going to use to search for the password. By editing this file appropriately you can tell the program to brute-force only combinations of specific characters, or fix the first part of the password and brute-force only the last part. If you have a bit of information about the password, you can use it to increase your chances of finding it.

cRaRk makes use of NVIDIA’s CUDA technology and AMD’s OpenCL technology. It is actually one of the fastest programs in its area.

Cons

There are no cons, but unfortunately the program isn’t updated anymore to add new features, but the author accepts bug reports found by users.

Alternatives

An alternative for recovering passwords from RAR archives is Unrar Extract and Recover (free) which uses dictionary-attack method to retrieve passwords. A good dictionary will raise significantly your chances of finding the password. If you want to unlock ZIP files, you can use Appnimi ZIP Password Unlocker (free). Its type of attack is brute-force.

Conclusion

An advanced user can make a lot out of this program, especially with a powerful system and a strong GPU. But be that as it may, the average user will probably have trouble setting up and using it to find a password. Recommended for experienced users.