C-RAM Group: 

Shahid Aslam Khan, Sue Ann Ung and Satneev Bhamra 

Application Notes

We have found some things that are very useful while working as a team on the EE 552 project.

Last Modified: October 5, 2001

 


 

Remote Screen Capture in the X-host Environment

  1. At a UNIX workstation terminal, determine the workstation your want to check the window of. This can be done by 'fingering' the person logged in at the workstation.
  2. Make sure the target terminal is running xhost. You can do this by first 'telneting' to the terminal or by remote log in. Then at the target terminal, type the following at the prompt.

% xhost +

  1. To initiate a screen capture, in the xterm window of the LOCAL terminal, type the following.

% xwd -root -display xxx.xxx.xxx.xxx:0.0 > filename

where xxx.xxx.xxx.xxx is the Internet Protocol (IP) address of the UNIX machine to be attacked. The attack in this case, is to capture the targeted machine's screen. The filename is the file where the screen capture will be saved on the attackers computer.

  1. To display the captured image enter:

xwud -infilename

  1. The Xwindows screen capture feature is not a software bug, but into XWindows for system administration and information sharing. This attack has the potential to be conducted through a firewall but no experiment has been done yet at this time. The exploitation of this xhost+ feature is undetectable and can be run at any time.