Windows Registry Forensics-Review

I read Harlan Carvey's "Windows Registry Forensics" on a flight to Florida last week so I thought I'd write up a little review.

If you haven't already read "Windows Forensic Analysis" I highly recommend you do so.

First of all I have a tremendous amount of respect for someone who is willing to put their thoughts to paper when it comes to digital forensics. It's a very difficult topic because things are always evolving. It also takes a tremendous amount of time to write a book,  I'm trying to help a buddy with just a few chapters in a book he started and it's extremely difficult.

I will admit that I was expecting a little more book when I first purchased it, the registry is such a large piece of the Windows OS that I really thought the book would be encyclopedic. That being said, I was not disappointed  by the content.

The book is layed out in 4 chapters: Analysis, Tools, Case Studies:System and Case Studies: User tracking.

The Analysis chapter covers the binary structure of the registry as well as it's main purpose to the operating system and to the users. A considerable amount of this section was review for me (ten years of sysadmin work) but I've never read anything that tears down into the physical on-disk structure of the registry at the lowest level. Harlan obviously spent some time in this section tearing the registry down to it's nuts and bolts.

The tools chapter: If you don't read Harlan's blog or keep up with who is doing what in the industry you'll be expecting him to spend 50 pages talking about EnCase. Instead he uses the chapter to talk about a myriad of other tools which are just as useful if not more so than EnCase. He spends a fair amount of time explaining his own Perl tool "Regripper" and how it came to be as well as encouraging readers to develop their own plugins for regripper. I personally use regripper on every case I work so I know how useful it is and have spent a fair amount of time trying to figure out how it odes what it does. The book helped explain a little bit of the "behind the curtain" thought process that went into it's design.


Case Studies: System. Here's where the book starts to really pick up. 72 pages of nuts and bolts and "Here's why I've spent the last 150 pages explaining all this crap to you."  I read this section twice.  The registry contains so much information about the state of a given system that it is imperative a good investigator knows what they are looking at, what is normal, and why. After reading Harlan's case studies I have a better understanding of the pieces I already knew about and some insight into other chunks of the registry that have never caught my eye. Excellent chapter.

Case Studies: Tracking user activity.  The most useful chapter in the book! I am familiar with registry artifacts found during an investigation. For the most part I know how to use those artifacts to forward or disprove a theory. Even with that knowledge this section caught me off guard with how little I really know. Especially good was the dissection of all the areas of the registry that can be used for malware persistence and the write up on "shellbags". I have run across these artifacts a dozen or more times in my supertimelines but never payed them all that much attention, I knew that they represented user activity of some kind, but it didn't seem related to any type of malicious activity. Now I know that I was correct in my assumption but I also know that those shellbags are definitive proof of an interactive session.

All in all, I enjoyed reading the book. Harlan keeps it personable while maintaining an air of technicality. So many books like this are so dry that they can't be read for more than 15 minutes. Not so in this case. I have absolutely no regrets on the purchase price and just like "Windows Forensic Analysis" I will be referring to this book for years to come and I'm glad I have it as a resource.

PCAnywhere or "Here Hacker, Hacker"

Let me start by apologizing to anyone that was enjoying fresh, regular content from my blog. I haven't written a new post in several months

 I am not without reason. Starting a new job and getting used to the way things are done on a new team is time consuming and can require a lot of focus.  A wise man once said: "If you don't know what you're doing, do it neatly"  It doesn't fit entirely, but the learning curve has been steep, and my first few cases were worked through slowly, carefully and methodically.

This is not to say that my next cases will be worked any less carefully, but I've found you develop a rhythm in an investigation and you have to let the evidence lead you down the path to the answer.

Case in point:

I have already had a number of POS breach cases where PCAnywhere was the point of intrusion. I will focus on 2 for the purpose of this blog.  These 2 cases were similar in that they were both running the same type of POS software and it was set up by the same integrator.

PCAnywhere is a 2 part remote administration utility that has been around for a number of years. I don't know exactly when it came out but I remember running into it as a system administrator at least 7 years ago. It has gone through a number of version upgrades over the years and the latest stable version is v 12.5.  The 2 parts are the client, which is usually used by the remote administrator to make a connection to a remote PC or server for maintenance. The second part is the listener which (obviously) resides on the client machine that is to be remotely managed. Here's a list of the versions and the port usage (by version) from Symantec:

I have used numerous pieces of PCAnywhere evidence in my cases. 

The first is the connection logs. By default they are located in %SystemRoot%\Program Files\PCAnywhere and have a .pl9 extension. These logs are extremely configurable in the software itself.  They are easily viewed by using a registered copy of PCAnywhere or by downloading a trial from Symantec. These logs could contain anything from a basic timestamp and a connection attempt ,to full Windows Event Logging and verbose connection details to include connecting IP, user id info, files transferred, etc. For a full list of logging options, see this site.  Obviously these logs are very useful to an investigation. Unfortunately,  they are rarely verbose and in many cases I have found that logging is not even enabled. 

I have a problem with this. ADMINISTRATORS: IF YOU ARE GOING TO OPEN A GAPING HOLE INTO YOUR CLIENT"S ENVIRONMENT, AT LEAST HAVE THE DECENCY TO PUT IN A STRONG PASSWORD AND SWITCH ON THE LOGS!  Yer killin' me. You're also costing your clients tens of thousands of dollars.

There are also a number of vulnerabilities related to the older versions of PCAnywhere. Search the CERT website to read further on them all.  US-CERT Site.  One of these older vulnerabilities allowed you to pass the listener a message that says your login type is "0" Which allows you to log in with full admin credentials using a null username and password. That's Kwality there.

A bit more in depth is a file that I have found extremely useful that you probably don't know about. When you log in using the graphical interface a file called aw.swp is generated. This file is a cachefile that is created to speed up Windows operation.  It is used every time you use the remote desktop via PCAnywhere. This leaves a nice trail of birth, modified and access times in the system timeline. I even found evidence of card-holder data being moved in the aw.swp file. My assumption is that the built-in PCAnywhere file transfer button was used to move a file containing captured data. No one at Symantec ever contacted me back on this issue.  

Nothing ground-breaking here. It just goes to show that some of the most common applications leave behind some very definitive evidence. Sometimes you just have to dig around a little bit for an explanation of why.

I'm putting the finishing touches on a presentation for this years round of conferences. It's called "I'm your MAC(b) Daddy" and focuses on using super timelines to solve breach cases. I will post it here if I don't get accepted. I also have a post on generating timelines for filesystems that are not supported by fls and mactime. 

New updates soon. Thanks for stopping by.

"Perl's" of Wisdom

I spent the afternoon prepping up a laptop to take with me when I work cases on the road. If you've read some of  my earlier posts you know that I really like open source tools.

Regripper, The Sleuth Kit, UnxUtils, F-Response(not open source but worth every penny) and Imdisk are just a few of the indispensable tools that I think you should be using if you're serious about forensics. This is not to say that you have to jump off the deep end and run everything from a linux box. I'm not afraid to admit that I like to use Windows on my laptops. I'm not even afraid to admit that I like Windows XP.  

Here's what I don't like:

I don't like switching back and forth between machines to accomplish basic tasks, even if it's just popping open a VM and minimizing it again. Lame, hate it, I want  to be able to do everything from one machine. Why? I guess I'm just lazy and stuff. I don't want to bring 4 laptops with me to work a case. But I do want to be able to solve it while I'm on site.

So here we go,  If you want to crack off a timeline while those disks are imaging, I only know one way. F-repsonse and  Perl scripts.  F-response lets you deploy a tiny little client to each workstation, terminal, server or whatever it is you want to image, and suck all that data down to a single point. This is infinitely easier than attaching a hard drive to every machine in an environment, and it gets better.

The extra added bonus to F-response is that it offers up a live, read-only, environment to play with while that painfully slow image is running. 

It really is this easy:

Load up F-response listener 

Deploy client to nearly any OS in existence

Push start

Run your favorite imaging client (I like FTK lite)

Image hard drives from a single point on the listener.

Here's the bonus.  On the same machine that functions as the F-response listener, you have a mapped drive to the same physical disks that you are imaging. They show up as a regular mapped drive! E:, F:, G:  all read-only and there for you to get your forensics on.

Want a sneak peak at your timeline? Bam! 

fls -m 'C:\' -f ntfs \\.\: > bodyfile

Want to do a little password crack-a-lackin? Done! Use Ftk-Lite and extract that SAM hive.

Drop those hashes into Ophcrack and watch those default passwords appear before your very eyes.

This is not to say it's all a cakewalk. Thanks to Harlan there are some awesome perl scripts floating around the internet that will help you. Forcing these scripts to work on a Windows box can be a chore. Trust me, I just spent half my day proving it.

Case in point: regtime.pl  

This is Harlan's superfly, TNT perl script that shreds all of the registry hives(including NTUSER.dat)  and spits them out in standard bodyfile format.  (go back a few months and see my post on super timelines for use)

 The only 2 places I know of to get regtime.pl from are Harlan's email and the SIFT workstation. I didn't want to bug my mentor's mentor too much so I chose the SIFT download. 1.5 GB's later I had all the contents of /usr/local/src/windows-perl saved to my desktop.

Easy right? Install active-Perl from the website and go? 

Wrong.

BONK!

No biggie, I'm missing a perl dependency right?  BONK!
There's something wrong with the script? BONK!
Something got screwed up when I copied it over from Linux? BONK!
My Perl environment is not the polished marble that Harlan's is?  Well, maybe....   BONK!


WTH is going on here? Thought 1 turns out to be correct. This is a dependency issue. Even after you've been through your environment 10 times and all your dependencies look sweet, there's the registry.pm file in the right path and  you've contacted the developer because you've ruled out everything else. (sorry Harlan, I owe you  expensive scotch when we finally meet).  It's really very clear in all of it's perly non-clarity.   It can't locate Parse/Win32Registry.pm and this is clearly a misplaced file in a directory path right?  Not exactly. 


Try this.
From the command line type "ppm" for the perl package manager, go to view and check "all packages".  Glory, Glory, Hallelujah.  There's a package called Parse-Win32Registry. Right click and install that bad boy.

Now when you try that mystical regtime.pl command it coughs up a perfect bodyfile.

Coders are a bubble off; I'm telling you.


Next trick:  Path variables.

The command "dir" sucks, "ls" does not

ls, grep, cat, and a whole host of others are available in the unxutils package. Go downlaod it and install it and while you're on the web grab strings and grep.

Once you've got all these ported apps installed you don't want to cd into a specific directory to use them right?  You want to be able to use the command like you're the one in control.

Editing your $PATH is the answer.

Right click  my computer and go to properties--go to "advanced"--"environment variables"

Highlight "PATH" and click edit.  Use a semicolon as a separator and add the full system path to your sexy new executables.

Pretty soon your path can look like mine:

C:\Python26\Scripts;C:\Python26\;C:\Perl\site\bin;C:\Perl\bin;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;C:\Tools\sleuthkit-win32-3.1.3\sleuthkit-win32-3.1.3\bin;C:\Tools\UnxUtils\usr\local\wbin;C:\Program Files\GnuWin32\bin;C:\Tools\sleuthkit-win32-3.1.3\sleuthkit-win32-3.1.3\bin


And my $PATH is dead sexy.

Best. Job. Ever.

So, I promised exciting news last post and then it dawned on me that it's only exciting to my family and I. Sorry for the letdown.

I started my new job on Monday the 27th. Not just any old new job, but a job with Trustwave's Spiderlabs. If you don't know who who or what Spiderlabs are, start with the company webpage, then look at all the DEFCON talks, whitepapers, blogs and everything else these guys are responsible for.  They are the top Incident Response and Computer Forensics team in the country (my opinion of course) and I am absolutely stoked about joining them.

How on earth did I land a job with Trustwave?

For starters I have a lot of very relevant experience. I can walk into a server closet and discern what goes to what and why within a few minutes. This is important when every case situation is a total unknown.

I also went out of my way on my own dime to go to DEFCON and meet prospective employers. I shook a lot of hands, bought some drinks and asked some good questions. (see: networking)

I got certified earlier this year(see my earlier posts on studying for the GCFA) and started a forensics division at my former employer, business was just starting to build up when I got this offer.

Lastly, I may be the single luckiest person I know!  Timing, luck and a personal relationship with one of their senior consultants all came together at just the right time and led to job interviews. The rest is now history.


So what's a new guy learn on his first 2 cases?

1) People are still making the same simple mistakes when it comes to System Administration and auditing. Plain and simple. If you open RDP, PCAnywhere or VNC up to the internet and leave a weak, default or blank password, consider yourself pwned!

2) Hackers are getting better and better at disguising malware as valid processes. I can't go into a lot of detail here but plain sight is still the best hiding place of all.

3) P.O.S. integrators are screwing their customers! This is not to say that there are not some good integrators out there, but seriously, you cannot just drop these systems into place and pay absolutely no attention to the basic security fundamentals. When you do, you wind up costing your customers tens and possibly hundreds of thousands of dollars in investigations and fines.  Buck up! Put in a Netgear Prosafe for $85 and change those default passwords......or don't, I guess it's job security.


Thanks for following along.

Grayson

A little more love for DEFCON 18

DEFCON featured a number of talks about the Zeus trojan and for good reason. I think it's the most sophisticated mass-use malware ever written.  It can keylog, hoard your credit card numbers and even join you to a global botnet. Fun stuff huh?


It's current known variants are  Zbot, PRG, Wsnpoem, Gorhax and Kneber.  


It can be very difficult to detect and remove because, every time you infect a machine, the signature changes. It's mass customization for malware!  The full package comes with a command and control php and sql webcenter for managing your unruly botnet as well as software for generating your very own custom malware. How much would you pay for this crystal-clear wonder? $4999? $3999?  Nope it can be yours for the low,low price of $500-$700 on the software black-market. (It should be noted that the latest version may cost you a few thousand).


So why do we care as forensic analysts?  


There are a couple pieces here:


1. It steals credentials and credit card data. Steal enough credit card data and the Feds will be hunting for you. This may lead to a forensic analysis of a host and Zeus is being found in the wild at credit card breaches. (I have it from an excellent source....)


2. Most commercial antivirus scanners will not detect or remove Zeus from an infected machine. These scanners are signature based (for the most part) and as I said before "every time you infect a machine, the signature changes".  


So now what? 


Forensic tools to the rescue!  

There are a number of ways to detect Zeus using a fairly common suite of forensic tools. I am not going to rehash someone elses work here. Kevin Stevens and Don Jackson have a fantastic write up on Zeus and its variants at the SecureWorks website. 

There is also a forensic breakdown of infected keys and tool usage here.  Really nice job Tyler. Most of this paper is based on results from memory analysis using volatility.

And what blog would be complete without mentioning regripper?  There is a third-party plugin called userinit that was written to find "urlzone" trojans. As a side effect it parses the same hive that the sdra64 binary attaches itself to (userinit).


That's it for me. I'm spending a lot of time studying for the CISSP exam.

Exciting news next post......

Good Luck.

DEFCON 18

I went to DEFCON 18 (Barely Legal) 2 weeks ago. It was a great con and I can't wait for next year. The sheer brainpower on display in that hotel was impressive.

I saw some great presentations on everything from forensic methodology to custom malware, met some feds, and watched ReL1K pwn him some Windows 7 boxes with powershell (seriously nice work on the Social Engineering Toolkit).

I even got to see Hope Dworaczyk (Playmate of the Year) get awarded "Best Reason To Get Malware" by the guys from Barracuda labs.  Friggin' sweet!

If you've never been, GO!  It's an educational experience to say the least. Seriously, who knew you could get a mohawk to stand up over two feet tall?

There are some very cool things on the horizon for the internet:

Dan Kaminsky demo'd  DNSSEC. Finally, a way to actually prove that an email, website or any other electronic communication actually came from who it said it did!  Dan is a stinkin' genius by the way. I look forward to his next project, whatever it is.

Anybody heard about this whole "smart grid" thing? It's going to suck. Every single "smart" device out there is going to be a hackers dream.  One guy put up a presentation called "iBurglar". It's a webscript that will parse the power usage data that people post on twitter, facebook, etc... It will turn around and produce a calendar of the best times to rob that person. Dude was not a burglar, he was just trying to make a point about how dumb it is to put that kind of personal information out there.  It worked! Smart grid + dumb people = problems.

There were several talks about SCADA systems and their importance in the future of cyberwarfare. SCADA systems are web-enabled controls for our public infrastructure that can be tampered with to create"weapons of mass distraction".  I doubt that they could ever be used to do any catastrophic damage, but they could be used to throw the general public into a tizzy.

Spiderlabs says "All your droid are belong to us"  Thanks for letting me think that my droid was secure for the first 6 weeks I had it anyway......jerks.


More on DEFCON next week.

Did you know that the Zeus trojan has a web command center and a GUI for creating new versions? Ridiculously easy to own your own botnet!

Ghosts!

I haven't posted in a while so I asked my 6 year old boy what he thought I should write about.

 "Ghosts!" was his immediate and emphatic answer.  I don't know how to explain to him that my blog is about digital forensics and related topics, so here I am writing about ghosts.   A ghost , as I understand it, is a physical manifestation of a person's soul after their body has died. I myself have never witnessed said manifestations, but I have had some pretty damn weird stuff happen to me in one of my homes and in the cave I worked at when I was a teenager. For the record, ghosts don't exist.

Neither do entry-level jobs for forensic analysts without a bachelor's degree.

I may have more luck looking for a forensics job if I ever decide to leave Montana. That's not a decision I ever want to have to make. Simply put, this place rocks!  So what's a guy do to try to make himself more marketable?  Certification and Education are a good place to start.

I have been studying for the CISSP exam for the last several weeks and plan to take the exam in September. CISSP also counts for  several credits towards a Bachelor's degree in Information Assurance and Security.

Bonus!

I Hated (yes, capital H) high school but I tried to go to community college right afterward, anyway.  I wound up feeling like it was just an even more miserable extension of the former so I withdrew (dropped out) midway through my second semester and joined the Navy.  I got lots of training in the Navy that I actually enjoyed, like math, science, electronics, computers, etc. After I got out, I took some Microsoft courses and took all the MCSE tests. I enjoyed those classes as well. Now I have 12 years of experience and a fistful of certificates from formal training as well as the GCFA cert and my MCSE.

It's time to go back and rectify the whole "dropped out" thing. I'm looking at a couple of the online colleges and gearing up to knock out a degree as fast as I can. I look at the curriculum and it causes me pain to have to take "Windows Server Networking" since I could likely teach the course.  But it has to be done. I'm no longer running into job postings that state "or equivalent experience".

Wish me luck.
I'll need it to stay awake for "Introduction to Unix"

P.S. I'm going to get back to some more technical posts in the near future.  I have a few system images to run through and post about.