All about Windows 7
When thinking about references we have available when performing digital forensic examinations on a Windows 7 system there aren’t a lot that come to mind. We have some great presentation slides (cough cough Troy Larson cough), a few blog posts, and the paper SWDGE Technical Notes on Microsoft Windows 7. However, there isn’t a DFIR book who’s main focus is about Windows 7 until now. WFA 3/e comes out of the gates talking about Windows 7 in Chapter 3. The chapter goes into great detail about volume shadow copies (VSCs). What VSCs are, how to access VSCs, different methods to examine VSCs, and different tools available to use against VSCs. The Windows 7 theme continued into Chapter 4 File Analysis with topics such as event logs and jumplists (a new artifact showing user activity). Rounding out the forensic nuggets about Windows 7 was Chapter 5 Registry Analysis. At first I was worried about reading the same information I read in Windows Forensic Analysis 2nd Edition or Windows Registry Forensics but my worries were unfounded. The author has said numerous times WFA 3/e is not a rewrite to his other books and is a companion book. The registry analysis chapter showed how true the statement is because it focused on what information can be pulled from Windows 7 registry hives. The author also highlighted the differences between Windows 7 and previous Windows operating systems. If anyone is going to be encountering Windows 7 systems then WFA 3/e will be one of the references to have within reaching distance.
Process, Process, Process
WFA 3/e discusses numerous Windows artifacts and different tools capable of parsing those artifacts. The book also provides context about the artifacts and tools by discussing the DFIR processes behind them. Right off the bat the author lays the foundation by discussing Analysis Concepts in Chapter 1. There is even a section about tools versus processes. A quote I liked was “analysts can find themselves focusing on specific tool or application rather than the overall process”. I see a lot of DFIR discussions focus on tools instead of the overall process on how those tools could be used. I even fell into this trap earlier in my career. Whenever I read a DFIR book or any analysis book for that matter I want to see the author explain the overall process because it makes it easier for me to translate the information over to my work. WFA 3/e did an outstanding job discussing processes which can be seen in various chapters. The two chapters I wanted to mention specifically are 6 and 7.
Chapter 6 Malware Detection was dedicated to how the author goes about to finding malware on a system. The author lays out the overall process he follows (a checklist accompanies the book) and then goes into detail about what he is looking for and what tools he uses to carry out the process. The same approach is used in Chapter 7 Timeline Analysis. The author discusses his process for performing timeline analysis including: how he approaches timelines, how he builds timelines, and how he examines timelines.
It’s nice to see the processes someone else uses and the case experiences shared by the author helped reinforced why the process is important. WFA 3/e doesn’t disappoint because the author not only provides tools to do DFIR work but he lays out a process that others can follow.
Don’t Overlook the Materials Accompanying the Book
The author made the supporting material to WFA 3/e available online (on this Google page) and this is a welcomed feature for those of us who bought the book’s electronic version. Similar to the author’s previous books I already mentioned, the materials accompanying his book are full of DFIR goodies such as ….
* jumplist parser (jl.pl): the author wrote a script to parse jumplists. This is the only command-line tool I know of that can parse jumplists. I tested script against jumplists inside VSCs and the results were impressive.
* Malware detection capability: there are different scripts to help with detecting malware including mbr.pl to find mbr infections and wfpchk.pl to check the contents of the dllcache.
* Checklists: there are a few different checklists that may be useful references during an examine.
* Source code: the source code is provided to all the scripts. I’m teaching myself Perl so being able to read the code helps me get a better understanding about not only knowing how the script works but how the author puts scripts together.
Clarification about ShadowExplorer
There were no significant improvements I could suggest to make WFA 3/e better. I could make a couple minor suggestions but there isn’t anything glaring. However, there was something I wanted to clarify. Chapter 3 Volume Shadow Copies Analysis mentions using ShadowExplorer to access and browse VSCs. The author mentioned that ShadowExplorer will only show the VSCs available within the volume or drive on which the program is installed on. That ShadowExplorer has to be reinstalled on the drive in order to view its VSCs. The section I’m referring to is on Kindle page 1,366. I might have misunderstood this statement and if I did then please ignore this section to my book review.
ShadowExplorer only needs to be installed on your forensic workstation and it can be used to view any volume’s VSCs mounted to the workstation. The drop down menu next to the drive letter lets you select any drive letter on the workstation to view that volume’s VSCs. I’ve used ShadowExplorer in this manner to view VSCs for drives connected to my system through USB docks and to view the VSCs inside a mounted forensic image. It's a nice way to preview VSCs.
Overall Five Star Review
Overall I give WFA 3/e a five star review (Amazon rating from 0 to 5 stars). The book has a lot to offer from Windows 7 artifacts to DFIR processes to better understanding the artifacts we encounter. As I said in the beginning to the post, the book is a welcomed addition to anyone’s DFIR library and it’s a great companion book to the author’s other books about digital forensics on Windows systems.
I wanted to say how humbling it was to see the author mention my blog. Before I became more active online I lurked in the shadows following a lot of people in the DFIR community. Harlan is one of those people. Every time I see someone mention me I am still taken back. I wanted to say thank you Harlan for the recognition and including an earlier version to my Regripper VSC batch script in your materials. (an updated version to the script can be found here).
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