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Brute forcing

Crowbar – 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 forcing 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.

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 (-b openvpn)
  • Remote Desktop Protocol (RDP) with NLA support (-b rdp)
  • SSH private key authentication (-b sshkey)
  • VNC key authentication (-b vpn)

Installation

# apt-get -y install openvpn freerdp-x11 vncviewer
# git clone https://github.com/galkan/crowbar

Usage

-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 see all usage options, please use: ./crowbar.py --help.

Example

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

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