RarCrack is a program that uses brute force algorithm to find and recover the correct password for compressed archive in .rar (WinRAR), .7z (7-Zip) and .zip (WinZip) format in any POSIX compatible operating system. As such, RarCrack is useful when you have forgotten or lost the password for the compressed archive package in the supported format. To make bruteforce password breaking faster, RarCrack supports specifying a selection of characters and digits to be used in password generations in order to crack the password.

The guide below is a brief explanation on how to use RarCrack to recover and retrieve back the password for .rar, .7z or .zip files. Note that RarCrack requires glibc 2.4, pthreads and libxml2 libraries in order to work. Use rpm, pkg_add, apt-get and other commands to install the dependencies if it’s not installed yet.
  1. Download RarCrack by using the one of the following commands (just the difference of downloading mirror) in terminal:
wget http://superb-east.dl.sourceforge.net/sourceforge/rarcrack/rarcrack-0.2.tar.bz2
wget http://kent.dl.sourceforge.net/sourceforge/rarcrack/rarcrack-0.2.tar.bz2
wget http://nchc.dl.sourceforge.net/sourceforge/rarcrack/rarcrack-0.2.tar.bz2
  1. Extract the RarCrack archive:
tar -xjf rarcrack-0.2.tar.bz2
  1. Change directory into the extracted RarCrack folder:
cd rarcrack-0.2
  1. Install the RarCrack with the following command:
make
sudo make install (so simply make install if already log in as root)
  1. To crack or break the RAR, 7z or ZIP file Password, use the following syntax:
rarcrack encrypted_archive.ext [--threads thread_num] [--type rar|zip|7z]
The switch in [] is optional. RarCrack can autodetect the archive type, so the –type parameter only require if auto-detection of file type is wrong. And by default, RarCrack launches two cracking threads if no thread number is specified.
For example,
rarcrack example.rar
rarcrack forget password.zip
  1. After starting the process to break and crack the password, RarCrack will print and save the current status of cracking to a XML status file. Any valid good password to open the archive, if found, will be printed as good_password variable. An example of the XML file is as follow:


0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ
uU

Tip: If you can barely remember the password but pretty confident that only certain characters or digits are used, modify the “abc” character set to include those characters or numbers only. On first use, run the RarCrack to generate the XML status file, then edit then file and rerun the RarCrack again.
To unlock a protected or locked RAR archive, use WinRAR Unlock instead