This document provides an overview of a presentation about using human interface devices like keyboards for penetration testing. The presentation covers using the Teensy microcontroller to create payloads that are executed when the device is plugged into a target system. It demonstrates writing payloads using the Kautilya toolkit to perform attacks like installing backdoors, changing system settings, gathering information, and executing code on Windows and Linux machines. The document also discusses limitations and ways to prevent attacks using malicious human interface devices.

1. Creating Havoc using Human
Interface Device
Nikhil Mittal

2. About Me
• SamratAshok
• Twitter - @nikhil_mitt
• Blog – http://labofapenetrationtester.blogspot.com
• Creator of Kautilya, Mareech and Nishang
• Interested in Offensive Information Security, new
attack vectors and methodologies to pwn systems.
• Previous Talks
– Clubhack’10, Hackfest’11, Clubhack’11, Black hat Abu
Dhabi’11, Troopers’12
• Upcoming Talks
– Training at Shakacon’12 and GrrCON’12

3. Agenda - Introduction
• A typical Pen Test Scenario
• How we are doing it
• Need for new methods to break into systems
• HID anyone?

4. Agenda - Workshop
• Introduction to Teensy
• Basics of Arduino Development Environment (ADE)
• Installing and configuring ADE to use with Teensy
• Understanding the basics of programming using ADE
• Writing Hello World
• Basic usage and programming of Teensy
• Introduction to Kautilya
• Demonstration of Payloads in Kautilya
• Program and perform attacks on a Windows machine
• Program and perform advanced attacks on a Windows machine
• Program and perform attacks on a Linux machine
• Understanding structure of and automation using Kautilya
• Understanding Integration of payloads in Kautilya

5. Agenda - Conclusion
• Protection against HID based attacks
• Pen Test Stories
• Limitations
• Future
• Conclusion

6. Let’s get started
• Be as interactive as you can. Query me, ask nasty
questions, insult me.
• It is mandatory to laugh on jokes, they be on slides or
cracked by me.
• We will start slow and then pick up speed. Be patient if
you know something, everybody is not good as you.
• I don’t have much theory so be ready to see demos
and source code.
• Make sure you keep your eyes on. You should be able
to program your device after this. I will keep checking if
everyone is awake ;)

7. A typical Pen Test Scenario
• A client engagement comes with IP addresses.
• We need to complete the assignment in very
restrictive time frame.
• Pressure is on us to deliver a “good” report
with some high severity findings. (That “High”
return inside a red colored box)

8. How the threats are Tested
Vuln
Exploit Report
Scan

9. • This is a best case scenario.
• Only lucky ones find that.
• Generally legacy Enterprise Applications or
Business Critical applications are not upgraded
and are the first targets.
• There is almost no fun doing it that way.

10. Some of us do it better
Enum Scan Exploit Report

11. Some of us do it even better
Enum
Post
+ Scan Exploit Report
Exp
Intel

12. Why do we need to exploit?
• To gain access to the systems.
• This shows the real threat to clients that we
can actually make an impact on their business.
No more “so-what” 
• We can create reports with “High” Severity
findings which bring $$$

13. What do we exploit?
• Memory Corruption bugs.
– Server side
– Client Side
• Mis-configurations
• Open file shares.
• Sticky slips.
• Man In The Middle (many types)
• Unsecured Dumpsters
• Humans
• <Audience>

14. Worse Scenario
• Many times we get some vulnerabilities but
can’t exploit.
– No public exploits available.
– Not allowed on the system.
– Countermeasure blocking it.
– Exploit completed but no session was generated
:P

15. Worst Scenario
• Hardened Systems
• Patches in place
• Countermeasures blocking scans and exploits
• Security incident monitoring and blocking
• No network access
• We need alternatives.

16. Need for new methods to break into
systems
• Bad guys are getting smarter.
• Smart attacks of 2011
– Sony (ok not so smart :P)
– RSA (clever attack), chained to Lockheed Martin
– Epsilon (Spear Phishing)
– Barracuda Networks (WAF turned off for little while)
– Some attacks on India
• Smart attacks of 2010
– Stuxnet
– Operation Aurora
• And Many more (like Apache in 2009)

17. Need for new methods to break into
systems
• Breaking into systems is not as easy as done in
the movies.
• Those defending the systems have become
smarter (at many places :P) and it is getting
harder to break into “secured” environments.
• Everyone is breaking into systems using the
older ways, you need new ways to do it better.

18. HID anyone?
• Wikipedia – “A human interface device or HID
is a type of computer device that interacts
directly with, and most often takes input from,
humans and may deliver output to humans.”
• Mice, Keyboards and Joysticks are most
common HID.
• What could go
wrong?

19. Introduction to Teensy
• A USB Micro-controller device.
• Storage of about 130 KB.
• We will use Teensy ++ which is an updated
version of Teensy.

20. From pjrc.com

21. Current usage of Teensy
• http://www.pjrc.com/teensy/projects.html
• Really cool projects.

22. Arduino - Installation
• Install Arduino
• Windows Serial Installer (only Windows)
• Install Teensyduino
• Detailed with screenshots here:
http://labofapenetrationtester.blogspot.in/2012
/04/teensy-usb-hid-for-penetration-
testers.html
http://www.pjrc.com/teensy/td_download.html

23. Arduino - Configuration
• Make sure to select correct “Board” and “USB
Type” under Tools menu item.
• If Teensyduino has been installed
properly, sketch examples could be found at
File->Examples->Teensy

24. Programming using ADE
• Almost C++ like syntax is used in ADE
• Two functions are required at minimum
– setup() which runs whenever Teensy is plugged or
restarted.
– loop() which keeps running after setup()
• Basic usage and programming of Teensy
• Writing Hello World with Teensy.

25. DEMO, Source Code and
Programming

26. Kautilya
• It is a toolkit which aims to make Teensy more
useful in Penetration Tests.
• Named after Chanakya a.k.a. Kautilya.
• Written in Ruby.
• It’s a menu drive program which let users
select and customize payloads.
• Aims to make Teensy part of every Penetration
tester’s tool chest.

27. Payloads
• Payloads are written for teensy without SD Card.
• Pastebin is extensively used. Both for uploads and
downloads.
• Payloads are commands, powershell scripts or
combination of both.
• Payload execution of course depends on privilege
of user logged in when Teensy is plugged in.
• Payloads are mostly for Windows as the victim of
choice generally is a Windows machine. 

28. Windows User Add
• Adds a user with Administrative privileges on
the victim.
• Uses net user command.

29. Default DNS
• Changes the default DNS for a connection.
• Utilizes the netsh command.

30. Edit Hosts File
• Edit hosts file to resolve a domain locally.

31. Enable RDP
• Enables RDP on victim machine.
• Starts the service.
• Adds exception to Windows firewall.
• Adds a user to Administrators group.

32. Enable Telnet
• Installs Telnet on victim machine.
• Starts the service.
• Adds exception to Windows firewall.
• Adds a user to Administrators group and
Telnetclients group..

33. Forceful Browsing
• Starts an invisible instance of Internet Explorer
which browses to the given URL.

34. Download and Execute
• Downloads an exe in text format from
pastebin, converts it back to exe and executes
it.

35. Sethc and Utilman backdoor
• Using registry hacks, calls user defined
executable or command when Shift is pressed
5 times or Win + U is pressed.
• When the system is locked, the called exe is
executed in System context.

36. Uninstall Application
• Uninstalls an msiexec application silently.

37. Chrome RDP
• This payload uses opens up chrome, launches
Remote Desktop plugin, enters credentials
and copies the access key to pastebin.
• This payload operates on browser window.

38. Information Gather
• Dumps valuable information from registry, net
command and hosts file.

39. Sniffer
• This payload pulls the sniffer powershell script
(by Robbie Fost) and executes it on the victim.
• The output is compressed and uploaded to
ftp.

40. Hashdump
• This payload pulls powerdump script of msf
from pastebin, schedules it as task to run in
system context and upload the hashes to
pastebin.

41. Keylogging
• This payload logs keys and pastes it to
pastebin every twenty seconds.
• There is a separate script to parse the output.

42. Wireless Rogue AP
• This payload creates a hosted network with
user define SSID and key.
• It also adds a user to Administrators and
TelnetClients group.
• It installs and starts telnet and adds it to
windows firewall exception.

43. Forced Wireless Connection
• This payload forces the victim to connect to an
attacker controlled WiFi AP. The AP in this case
is portable WiFi hotspot on a smartphone.
• Using this either payloads can be pulled from
the smartphone or the internet using the AP
thus effectively bypassing any internet
restriction policies on the system.

44. Code Execution
• This payload uses the powershell code
execution script (by Matt from exploit-monday
blog).
• A meterpreter shell is executed completely in
memory using this script.

45. Java Signed Applet Code Exec
• This payload browses in background to a url
where Metasploit Java Signed Applet module
is hosted and accepts the run prompt after
few seconds.

46. Time based payload execution
• This payload waits till the given time,
downloads a payload at the time and execute
it.

47. WLAN keys dump
• This payload dumps WLAN keys in clear text
and upload them to pastebin as a private
paste.

48. Pen Test Stories Could you
please plug
this in for
me?

49. Pen Test Stories
Library Fun
• We were doing internal PT for a large media
house.
• The access to network was quite restrictive.
• The desktops at Library were left unattended
many times.
• Teensy was plugged into one system with a
sethc and utilman backdoor.
• Later in the evening the system was accessed
and pwnage ensued.

50. Pen Test Stories
Breaking the perimeter
• A telecom company.
• We had to do perimeter check for the firm.
• The Wireless rogue AP payload was used and
teensy was sold to the clients employees
during lunch hours.
• Within couple of hours, we got a wireless
network with a administrative user and telnet
ready.

51. Pen Test Stories
Help by the Helpdesk
• A pharma company.
• We replaced a user’s data card with a Teensy
inside the data card’s cover.
• The payload selected was Keylogger.
• “Data card” obviously didn’t worked and we got
multiple keylogging for the user and the
helpdesk.
• Helpdesk guys had access to almost everything in
the environment and over a workday, it was over.

52. Defense from malicious HID
• Use Endpoint Protector 4 :P :P
• Group Policy in Windows which prevent
installation of hardware devices.
• UDEV rules for Linux.

53. Limitations with Teensy
• Limited storage in Teensy. Resolved if you
attach a SD card with Teensy.
• Inability to “read” from the system. You have
to assume the responses of victim OS and
there is only one way traffic.

54. Limitations with Kautilya
• Many payloads need Administrative privilege.
• Lots of traffic to and from pastebin.
• Inability to clear itself after a single run.
• Not very stable as it is still a new tool and has
not gone through user tests.
• For payloads which use executables you
manually need to convert and paste them to
pastebin.

55. Future
• Improvement in current payloads.
• Implementation of SD card.
• Use some payloads as libraries so that they
can be reused.
• Support for Non-English keyboards.
• Maybe more Linux payloads.
• Implementation of some new payloads which
are under development.

56. Thank You
• Please complete the Speaker Feedback Surveys.
• Questions?
• Insults?
• Feedback?
• Kautilya is available at
http://code.google.com/p/kautilya/
• Follow me @nikhil_mitt
• http://labofapenetrationtester.blogspot.com/