Hacking Exposed Computer Forensics Blog

Daily Blog #270: Bsides Austin 2014

Hello Reader,
I had a great time today at Bsides Austin. When I come to conferences that are primarily information security focused I feel like an ambassador to the world of DFIR. I always try to explain to them what lead me out of the infosec world and into DFIR and why I feel its a better place long term. I gave the same talk here that I did at Bsides DFW but to tell the truth, I didn't stick to the slides very much. I took the time to explain whats possible with filesystem journal forensics and then extend that with other operating system artifacts for NTFS/HFS+ and EXT3 so they could understand what possible now.

I was very encouraged the majority of the audience identified themselves as doing some kind of incident response and got the concepts I was going over. I also didn't get the 'how would you defeat truecrypt if someone says they forgot their password' question until the last 5 minutes, you know you are 'that guy'! So with all of that being said I hope that some people are interested into joining the ranks of DFIR professionals as we all know we need more of us! Here is a link to download today's slides for those of you who wanted to focus more on the data structures I didn't cover.

https://drive.google.com/file/d/0B_mjsPB8uKOAdlJKd19Zc1MybVE/edit?usp=sharing

And here is the signup form for the last month of the Triforce beta:
https://docs.google.com/forms/d/1GzOMe-QHtB12ZnI4ZTjLA06DJP6ZScXngO42ZDGIpR0/viewform

Daily Blog #269: Cool! When did FTK start doing that? #1 Create/mod dates of Carved PDFs from PDF metadata

Hello Reader,
Occasionally in our work we stumble across new features from our tools that suddenly makes our lives easier. A long time ago I blogged about when FTK made the 'export lnk metadata' option available which made our lives so much easier. Today I want to talk about something else they just kinda put in and don't know when.

FTK is now correctly parsing out the creation and modification dates (if they exist) from carved pdf files and placing them in the correct fields within the interface. This may sound simple and apparent but for a very long time any carved file within FTK would have no time entries as well, they had no file timestamps... they were carved. What we saw this week was for those files that have timestamps within their metadata FTK is starting to pull this out in the processing of the carved file and sticking them into their relevant timestamp location.

Does this sound simple? It is, but it can be a huge time saver! Here is an example. I have a pdf file that I'm looking for an image that has been deleted and is no longer recoverable from all the usual locations (recycle bin, mft deleted file record, shadow copy, etc..) so I have to carve to find it. I know the date the file was created on the system as I still have a shellbag from the desktop access of the file, but I believe that it is a scanned image stored in a pdf. This presents a problem as I can't just do a keyword search for what I think the file contains as its an image.

You could try to OCR all of the carved pdf's and then search for keywords, but calling the OCRing of carved data (which may be incomplete and curropted) failure prone is being kind. So instead I was able to filter my file list for carved pdf's and then sort by create date. Boom there was one carved pdf created on the same day as the shellbag entry pointing to it. A quick preview of the file within Adobe Reader and I had what I was looking for.

So the next time you are what appears to be a huge lake of carved data trying to find a file interest, check to see if the tool you are using is exposing the dates stored within the document metadata it could be your ticket to a quick resolution.

Daily Blog #268: SANS DFIR Summit details

SANS DFIR Summit details by David Cowen - HECF Blog

Hello Reader,
You may have seen on Sunday's post some information about my upcoming talk at the SANS DFIR Summit. I thought I would spend some time this week talking about each of the events I'll be talking about in detail so you can set your expectations on which event you'd like to see me at the most (or all of them!). I try to always talk about something different at the major events to keep things interesting for both of us. I also always put my slides up from the event here on the blog, maybe one day they'll let me put up recordings of the talks as well!

Click here to learn more about the event and see the schedule.

Today I wanted to focus on the SANS DFIR Summit as they choose a topic I submitted and was hoping they would like called 'Best Finds of 2014'. I'll be speaking on the first day at 1:45pm in Track 2. I'm excited about this talk because of the huge amount of space SANS has granted me to operate within the topic. Typically when I submit a topic to a CFP I have to choose one particular aspect of our research and focus on it for an hour, which you'll see me doing at other conferences this year. This topic though let's me really show you a wider survey of whats really cool and more importantly forensically useful from a whole years worth of research. I'll be hitting the highlights through all of the best artifacts we've covered here in the blog and those that we've only talked about during the Forensic Lunch.

I've found continued success in our own cases this year with the artifacts and analysis techniques I'll be showing this year and I'll give case citations to those of you who need to support using new artifacts by proving their use in past cases. My citations will be for US Civil courts (state and federal) so for those of you on the criminal side you'll likely have to do more validation. So I'm very confident in the utility of these artifacts having used them and defended them in court and achieving great results for our clients.

Here is the list of topics I proposed back in January:

Detecting writes to NTFS disks with the ntfs-3g driver
Recovering MTP access
Outlook attachment access through USN Journals
Artifacts from renaming accounts in Windows 7
Using task scheduler logs to recover past login

I'll be adding more to that list as we just keep finding more cool stuff! I love forensics, if you couldn't tell, and there is still so much we don't know that can lead to conclusive results and findings.

In addition to all of that SANS has made buying a ticket to the event much more affordable. If you use the discount code 'SUMMIT' now through March 31, 2014 the cost of a ticket will drop by $1,000. So the two day SANS DFIR Summit would just be $495 which includes great technical presentations (no sales pitches here) and lots of fun and socializing with your fellow forensic friends.

If that is still too much for your training budget you can still win a free pass to the event in upcoming Sunday Fundays so you have lots of opportunities to come down to Austin this June!

Daily Blog #267: Sunday Funday 3/16/14 Winner!

Sunday Funday winner by David Cowen - Hacking Exposed Computer Forensics Blog

Hello Reader,
Another Sunday come and gone with another individual added to the list of winners, only three months left of my year of blogging so make sure you get your shot in the coming weeks! This weeks' iCloud challenge got a lot of responses with varying degrees of information. This weeks' winning answer took me a few reads to really 'get' but the information provided is the most complete so its worth reading a couple times to get it right. So Congratulations Thomas Pullen you won this week's challenge!

The Challenge:

Cloud backups of mobile devices are now built into almost every major operating system. For iOS devices please answer the following questions.

1. How many backups per device would you expect to find?
2. What triggers a backup to the cloud to occur?
3. What tools currently exist to access icloud backups?

The Winning Answer:

Thomas Pullen

Apple gives 5gb free storage per device unless you buy more, so you'd only expect to find 1 backup per device. backup is incremental. devices CAN have multiple backups if there is enough storage (50gb is the current maximum). i don't think there is a limit to the number of backups made other than account storage, but when restoring the IOS device it may limit to the most 3 recent backups made.

iCloud doesn't backup everything, just the following:

-Photos and videos in your Camera Roll
-Device settings
-App data
-Home screen and app organization (not the apps themselves)
-iMessage, text (SMS), and MMS messages
-Ringtones
-Visual Voicemail
-the first 1,000 photos of photo stream, if enabled (photos don't count towards storage limit)
-icloud keychain was introduced with IOS7. this is a dubious thing to store in the cloud, and a perfect reason to use elcomsoft phone password breaker.

note that you can have up to 10 iCloud accounts per device, but only one iCloud account can be the primary account (associated with your Photo Stream, Find My iPhone, Backups, and document sync). Secondary (and tertiary) accounts can only sync mail, contacts, calendars, reminders, bookmarks, and notes.

so technically, if the IOS device has 10 iCloud accounts, you can actually have 20, 30, 40 "iCloud backups" per device, although only 1 is the primary one. to be more precise, the secondary accounts would probably live inside the backup of the main account, but it's still the backup of separate iCloud email, notes, etc.
i think...but i'm not sure...that these other iCloud account info would still be backed up in the phone's primary iCloud account. see http://support.apple.com/kb/ts4020.
however it's rare that users buy more storage space so most people have just the 5gb.

Backups occur when the user has an iCloud account added to the phone, and the phone is plugged in to a charger, locked, and connected to a wi-fi network.
Also, backup can be forced...settings, iCloud, storage and backup, backup now.

iCloud data is stored in public cloud storage, usually Amazon or Microsoft servers.(!) Apple encrypts the data and holds the encryption keys.

elcomsoft phone password breaker can access some of the iCloud data stored online without alerting the user that it's been used. even if two-step verification is used. however, and this is important, you need the apple ID and password. see http://www.theregister.co.uk/2012/05/17/elcomsoft_data_retrieval_tool/ and http://www.elcomsoft.com/eppb.html

also, a court order could force apple to turn over the data to LEOs or agencies. it goes without saying that access to a computer with iTunes backups is often helpful.
also, there is social engineering...ask the user, get their apple ID and password however you can.

tools that just retrieve email, or adding the iCloud account to a windows or mac, or just logging into iCloud.com aren't strictly speaking "accessing the iCloud backup" so aren't worth mentioning here. right now, the only ways i know to access the actual iCloud backup are to use Elcomsoft or get Apple to deliver it to you via court order.

Daily Blog #266: Sunday Funday 3/16/14

Hello Reader,
It's Sunday and time for another challenge as today's post crosses into the final 100 blogs of my year of blogging. I've thoroughly enjoyed this challenge as it has forced me to keep publishing research, findings, interesting things and other excuses to write a blog.I hope you've enjoyed it as well and I hope to see you at one of the conferences I'll be speaking at this year. One of the one's I'm most excited about is the SANS DFIR Summit, you can read more about it here, where I'll be on a panel of DFIR authors as well as presenting my favorite forensic finds that I've found in the year of blogging. For today's challenge let's talk about mobile phone forensics as discussed by Vladimir Katalov of Elcomsoft on this week's Forensic Lunch.

The Prize:

A $200 Amazon Gift Card, delivered by email

The Rules:

You must post your answer before Monday 3/17/14 2AM CST (GMT -5)
The most complete answer wins
You are allowed to edit your answer after posting
If two answers are too similar for one to win, the one with the earlier posting time wins
Be specific and be thoughtful
Anonymous entries are allowed, please email them to dcowen@g-cpartners.com
In order for an anonymous winner to receive a prize they must give their name to me, but i will not release it in a blog post

The Challenge:
Cloud backups of mobile devices are now built into almost every major operating system. For iOS devices please answer the following questions.

1. How many backups per device would you expect to find?
2. What triggers a backup to the cloud to occur?
3. What tools currently exist to access icloud backups?

Daily Blog #265: Saturday Reading 3/15/14

Hello Reader,
It's Saturday! If you are working the weekend than just think that all those annoying co-workers who normally bug you aren't there today! It's time to learn something new while you watch the progress bars flow on this weeks Saturday Reading.

1. We had another great Forensic Lunch today, I hope you will consider making time in your Friday to watch it live someday as I think its just way more fun live. You can watch it here:
https://www.youtube.com/watch?v=BtB8DA4dQ7s&list=UUZ7mQV3j4GNX-LU1IKPVQZg

This week we had in order of appearance:

Jake Williams, @malwarejake, talking about the results of the SANS Endpoint Security survey and the positions they are looking to hire at the Mayo Clinic for those of you looking for senior DFIR positions!
You can also train with jake next month in Orlando and elsewhere, go here to see the classes he's teaching https://www.sans.org/instructors/jake-williams.
SANS/Guidance Endpoint Security Survey Webcast - http://bit.ly/1hYUYMU
Alissa's Memory Forensics Class - Orlando, http://bit.ly/1e0ZEkD
Jake's Log Management and Forensics Class - Orlando, http://bit.ly/PBqkQy
Jake and Alissa's Memory Forensics vLive class - http://bit.ly/1imyw0V

Brian Baskin, @bbaskin, talking about his research, blog (ghetto forensics), books (here is an amazon link), and his work at DC3 where they are looking for people interested in DFIR with a clearance who live in the Baltimore area! Reach out to him if you are interested.

Vladimir Katalov, @vkatalov, the CEO of Elcomsoft talking about upcoming research regarding iCloud key chain recovery from network traffic, Blackberry 10 backups, accessing cloud storage and which gpus work well for long term password cracking. You can go to elcomsoft's website here and these are my favorite tools they sell:
Elcomsoft Phone Password Breaker http://www.elcomsoft.com/eppb.html, great for cracking encrypted phone backups and accessing iCloud backups!
Elcomsoft iOS Toolkit, http://www.elcomsoft.com/eift.html, great for low level working in iOS forensics.
Elcomsoft password cracking bundle, http://www.elcomsoft.com/eprb.html, a nice collection of there password cracking tools

2. Alissa Torres has a cool blog up on the SANS blog about carving network streams from memory dumps, check it out http://digital-forensics.sans.org/blog/2014/03/14/stream-based-memory-analysis-case-study.

3. A reminder there is still time to nominate your favorite DFIR software vendor, blogger, tool maker and personalities for Forensic 4:cast awards, Go here: http://forensic4cast.com/forensic-4cast-awards to nominate. Speaking as someone who was nominated and won an award last year I can say that it really does make the day of the person you nominate to even see their work recognized. So do the community a favor and nominate those who you feel deserve it!

4. Colby Lahaie has a blog up involving his capstone research to fulfill his degree requirements over at Champlain. He's researching the what the cloud storage program Idrive leaves behind from a disk and network point of view. Keeping up with the cloud can be tough so I am always looking for more information, read it here: http://lahaie4n6.blogspot.com/2014/03/whats-life-like-in-clouds.html

5. Brian Moran has a new post up about lessons learned from his recent weeks in the field, http://brimorlabs.blogspot.com/2014/03/some-quick-lessons-learned.html. Learning lessons from others who are where you may be in the near future can save you a lot of trouble later.

6. Andrew Hay landed at Open DNS and wrote a blog post about life as a researcher, I like it! http://labs.umbrella.com/2014/03/10/only-easy-research-day-was-yesterday/

7. Hidden Illusion has a neat blog post up on using Yara to brute force Xor encoded strings, http://hiddenillusion.blogspot.com/2014/03/bruteforcing-xor-with-yara.html.

8. Corey Harrell has a new blog up this week talking about how he got into DFIR, I hope someday to get Corey to come on the lunch and talk about himself and his work. http://journeyintoir.blogspot.com/2014/03/lose-yourself-in-dfir-music.html

That's all for this week, let me know if I missed anything either in the comments, twitter or email. I'm always looking for more good things to read!

Daily Blog #264: Forensic Lunch 3/14/14 - Discussion with Jake Williams, Brian Baskin, and Vladimir Katalov

Happy Pi Day Reader!,
We had another great Forensic Lunch today, I hope you will consider making time in your Friday to watch it live someday as I think its just way more fun live. This week we had in order of appearance:

Jake Williams, @malwarejake, talking about the results of the SANS Endpoint Security survey and the positions they are looking to hire at the Mayo Clinic for those of you looking for senior DFIR positions!

You can also train with jake next month in Orlando and elsewhere, go here to see the classes he's teaching https://www.sans.org/instructors/jake-williams.
SANS/Guidance Endpoint Security Survey Webcast - http://bit.ly/1hYUYMU

Alissa's Memory Forensics Class - Orlando, http://bit.ly/1e0ZEkD

Jake's Log Management and Forensics Class - Orlando, http://bit.ly/PBqkQy

Jake and Alissa's Memory Forensics vLive class - http://bit.ly/1imyw0V

Brian Baskin, @bbaskin, talking about his research, blog (ghetto forensics), books (here is an amazon link), and his work at DC3 where they are looking for people interested in DFIR with a clearance who live in the Baltimore area! Reach out to him if you are interested.

Vladimir Katalov, @vkatalov, the CEO of Elcomsoft talking about upcoming research regarding iCloud key chain recovery from network traffic, Blackberry 10 backups, accessing cloud storage and which gpus work well for long term password cracking. You can go to elcomsoft's website here and these are my favorite tools they sell:
Elcomsoft Phone Password Breaker http://www.elcomsoft.com/eppb.html, great for cracking encrypted phone backups and accessing iCloud backups!
Elcomsoft iOS Toolkit, http://www.elcomsoft.com/eift.html, great for low level working in iOS forensics.
Elcomsoft password cracking bundle, http://www.elcomsoft.com/eprb.html, a nice collection of there password cracking tools

Also Read: Decrypting images with a little help from Arsenal Image Mounter

full disk encryption

Daily Blog #263: Decrypting images with a little help from Arsenal Image Mounter

Hello Reader,
Looks like I need some more time before I finish up my work with Hal's mlocator and mlocate-time scripts, so instead of finishing that series I thought I would post about something cool that I found with a client. Hello client who is not being named directly! It was good seeing you this week.

So, let's say you have an image of a full disk encrypted drive and you want to get a tool that doesn't support transparently decrypting the disk (something tools like FTK and Encase can do) to work with the image. Now what we are about to talk about here assumes that you have the password/recovery key/private key whatever it is you need to decrypt the disk, so don't think this is some magic backdoor mechanism for encrypted disks.

Step 1. The first thing you'll need to do is get your disk image into raw/dd format. If you have it in another format you can convert most formats to raw using FTK Imager. If this sounds confusing I'll post another blog showing how to do this. If you made a raw image then your ready to go!

Step 2. You need to decide if you want to keep a copy of the encrypted disk image, and thus have two images one encrypted and decrypted. I would recommend this for criminal cases as they have a higher burden of proof but not for civil cases.

Step 3. Take the raw image and use Arsenal Image Mounter to mount it as a physical volume. The trick here again lies in that AIM is going to get Windows to recognize the disk as a physical volume via iSCSI.

Step 4. You will choose the option to modify the original image rather than make it read only or have an overlay file.

Step 5. Your encrypted physical disk image is now present on your computer and will interact as any other physical disk. You should now load up whatever encryption software was used to encrypt the disk in the first place and enter the passcode/recovery key to unlock the drive. For Bitlocker drives (what we tested this week) the dialog will just pop up and say Hey Buddy! This is a bitlocker drive, got the recovery key?

Step 6. Remove the drive encryption, in Bitlocker you just have to go to the control panel->bitlocker and turn off bitlocker on the mounted image.

Step 7. Wait for the decryption to finish and unmount the image.

There you go, you're done! The image you mounted has now been modified and contains a full decrypted disk image and ready to work with any tool you have that supports raw disk images.

This method isn't perfect but it does solve some issues and if you keep a copy of the encrypted image you'll always be able to go back and either repeat the procedure or load it a tool that supports the encryption suite directly.

I'll make another post like this specifically for Bitlocker next week when I have time to make some test data.

Also Read: Daily Blog #262

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