Crowbar (Levye) – Brute forcing tool
What is Crowbar?
Crowbar (formally known as Levye) is a brute forcing tool that can be used during penetration tests. It was developed to brute force some protocols in a different manner according to other popular brute force tools. As an example, while most brute forcing tools use username and password for SSH brute force, Crowbar uses SSH key(s). This allows for any private keys that have been obtained during penetration tests, to be used to attack other SSH servers.
Currently, Crowbar supports:
- OpenVPN (
- Remote Desktop Protocol (RDP) with NLA support (
- SSH private key authentication (
- VNC key authentication (
Install all the dependencies:
# apt-get -y install openvpn freerdp-x11 vncviewer
Then get the 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 use
- Else you can try
- Else you may need to compile & tweak
freerdpby following: http://opentechnotes.blogspot.co.uk/2015/02/compile-headless-freerdp-credential-checking.html
Don’t forget to edit the script to point to the new binary!
-h: Shows a help menu -b: Target service. Crowbar supports:
vnckey. -s: Target IP address/range (in CIDR notation) -S:
</path/to/file>which is stores target IP addresses -u: Single username -U:
</path/to/file>which stores the username list -n: Thread count -l:
</path/to/file>to store the log file (default is
</path/to/file>to store the successfully attempt(s) (default is
./crowbar.out) -c: Static password -C:
</path/to/file>for passwords list -t: Timeout value -p: Port number (if the service is not on the default port) -k:
</path/to/file-or-folder>for key files (for SSH or VNC) -m:
</path/to/file>for a OpenVPN configuration file -d: Run nmap on the IP range (in
-S) in order to discover whether the targets has an open port or not. This allows for multiple targets to be easily brute forced using Crowbar -v: Enable verbose mode (shows all the attempts) -q: Enable quiet mode (only show successful logins)
If you want see all usage options, please use:
ATTENTION: 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 - "DOMAIN\gokhan 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.
# ./crowbar.py -b rdp -s 192.168.2.182/32 -u admin -c Aa123456
# ./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
# ./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
# ./crowbar.py -b sshkey -s 192.168.2.105/32 -u root -k /root/.ssh/
# ./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 184.108.40.206/32 -p 443 -m /root/Desktop/vpnbook.ovpn -k /root/Desktop/vpnbook_ca.crt -u vpnbook -c cr2hudaF