Rootkits:

What they are, and how to find them

Welcome    Why?    Training    Games    ChangeBlog    External Resources    Submit Content

 

Creator:     Xeno Kovah  @XenoKovah


License:    Creative Commons: Attribution, Share-Alike

(http://creativecommons.org/licenses/by-sa/3.0/)


Class Prerequisites: You are recommended, but not required, to have taken Introduction to x86, Intermediate x86, and Life of Binaries.


Lab Requirements: Requires a Windows XP virtual machine. Rootkits are installed into the machine per the instructions in the TiddlyWiki class materials.


Class Textbook: “The Rootkits Arsenal” by Bill Blunden. (All page references in the class material are currently for the 1st edition book, the 2nd edition is not recommended.) This book was chosen because it contains the broadest coverage of rootkit topics. “Rootkits: Subverting the Windows Kernel” is good as well, but getting a bit dated. Recommended, but not required, is Windows Internals 6th edition, Part 1 and Part 2. This provides a large amount of detail on Windows’ internals, of which rootkit-relevant components are a small part. But the books can provide additional information that people interested in deep system security may be interested in.


Recommended Class Duration: 2 days


Creator Available to Teach In-Person Classes: Yes


Author Comments:


Introductory Intel x86, Intermediate Intel x86, and Life of Binaries are strongly recommended to be taken before of this class.


Rootkits are a class of malware which are dedicated to hiding the attacker’s presence on a compromised system. This class will focus on understanding how rootkits work, and what tools can be used to help find them.


This will be a very hands-on class where we talk about specific techniques which rootkits use, and then do labs where we show how a proof of concept rootkit is able to hide things from a defender. Example techniques include

•Trojaned binaries

•Inline hooks

•Import Address Table (IAT) hooking

•System Call Table/System Service Descriptor Table (SSDT) hooking

•Interrupt Descriptor Table (IDT) hooking

•Direct Kernel Object Manipulation (DKOM)

•Kernel Object Hooking (KOH)

•IO Request Packet (IRP) filtering

•Hiding files/processes/open ports

•Compromising the Master Boot Record (MBR) to install a “bootkit”


The class will help the student learn which tools to use to look for rootkits on Windows systems, how to evaluate the breadth of a tool’s detection capabilities, and how to interpret tool results.


This class is structured so that students are given a homework to detect rootkits *before* they have taken the class. This homework is given in the context of the following scenario:


“You, being the only ‘security person’ in the area, have been called in to

examine a running Windows server because "it's acting funny." They don't

care that you like Mac/Linux/BSD/Plan9 better, you need to look at it! You

are solemnly informed that this is system is mission critical and can only

be rebooted if absolutely necessary. You must investigate whether any sort

of compromise has taken place on the system, with minimal impact to the

mission. What do you do? What DO you DO?”


The homework is then for the student to use any means at their disposal to write up answers to the following questions: “What malicious changes were made to the system?”, “What tools did you use to detect the changes?”, “How can you remove the changes?”. The students’ answers are then anonymized and shared with the rest of the class afterwards, so that they can see how others approached the problem, and learn from their techniques. The anonymization of the homework before distribution is important so that students know that even though they don’t know, and aren’t expected to know, anything about the area yet, their entry will not be judged by other students.


A student Q&A forum has been set up at http://www.reddit.com/r/OST_Rootkits.


To submit any suggestions, corrections, or explanations of things I didn’t know the reasons for, please email me at the address listed above.




Author Biography: Xeno has a BS in CS from UMN, and an MS in security from CMU, which he attended through the National Science Foundation Scholarship for Service (aka CyberCorps) program. He has been attending security conferences since 1999 and working full time on security research since 2007. His current research work involves detecting rootkits and malware from kernel level down into firmware/BIOS.



Class Materials


All Materials Except Rootkits & Detectors(below) (.zip of ppt(242 slides), lab creation TiddlyWiki(html+javascript), anonymized homework writeups(txt&pdf), rootkit detector comparison matrix circa 4-8-2011(xlsx))
All Materials Except Rootkits & Detectors(below) (.zip of odp(242 slides), lab creation TiddlyWiki(html+javascript), anonymized homework writeups(txt&pdf), rootkit detector comparison matrix circa 4-8-2011(ods))
All Materials Except Rootkits & Detectors(below) (.zip of pdf(242 slides), lab creation TiddlyWiki(html+javascript), anonymized homework writeups(txt&pdf), rootkit detector comparison matrix circa 4-8-2011(xlsx,ods))


WARNING! password = “infected” because AV *will* flag on some of these files.


(Collection of Rootkit detectors. Some used in class some not. Most likely out of date by the time of download) - Password = “notinfected”, but my AV doesn’t like flister, so yours might not either.


Slides Part 1 (Rootkits taxonomies & overview + how material from previous classes applies to rootkits, 110 slides)
Slides Part 2 (Rootkit aspects not seen in previous classes, e.g. SSDT, 69 slides)
Slides Part 3 (Memory analysis w/ Volatility, KOH, 63 slides)
Lab creation instructions TiddlyWiki (a standalone wiki implemented with html+java)
Anonymized homework answer writeups (learn from seeing how some students approached the central lab).
Rootkit detector comparison matrix circa 4-8-2011



Full quality downloadable QuickTime, h.264, and Ogg videos at Archive.org:

Day 1 Part 1 (52:37, 597 MB)

Day 1 Part 2 (1:11:23, 739 MB)

Day 1 Part 3 (58:56, 830 MB)

Day 1 Part 4 (1:04:34, 675 MB)

Day 1 Part 5 (57:56, 697 MB)

Day 1 Part 6 (1:00:29, 750 MB)

Day 2 Part 1 (53:17, 731 MB)

Day 2 Part 2 (1:00:29, 693 MB)

Day 2 Part 3 (1:03:57, 946 MB)

Day 2 Part 4 (50:19, 511 MB)

Day 2 Part 5 (1:02:54, 695 MB)

(10:56:51 total, sans lab time)


The videos are useful for students, but also more useful for potential instructors who would like to teach this material. By watching the video, you will better understand the intent of some slides which do not stand on their own. You are recommended to watch the largest size video so that the most possible text is visible without having to follow along in the slides.



Revision History:


03-17-2013 - Made fine-grain class map more prominent

04-14-2012 - Uploaded videos to Youtube

01-15-2012 - Added “undetectable” keylogger lab creation steps to TiddlyWiki

09-21-2011 - Videos uploaded

06-31-2011 - in-class revisions

05-19-2011 - Initial class content upload


If you have used and modified this material, we would appreciate it if you submit your modified version for publishing here, so that all versions can benefit from your changes.