Forensic Imaging Station – Steampunk Edition

I’ve worked remotely for the past 6 years which means I spend a lot of time in my home office.  Last year we moved into a new house with much better space for my office, and I’ve been shaping it more and more to my tastes.

I do a lot of forensic imaging. I’ve got a pretty basic but rock solid setup that works for me (see Forensic Imaging a Microsoft Surface Pro).  Since I use it frequently I’m hesitant to put it away, but at the same point I don’t like looking at a pile of wires and devices when not in use. That brings us to the latest home office update, the Forensic Imaging Station (Steampunk Edition).

For this project I grabbed a small wooden box from Hobby Lobby.  A good cigar box will also work.  That was going to be my first choice but the only spare box I had on hand said “Corona” on the face and… you know. This box looks nice but it’s composed of mostly particle board, so go slow drilling.

I drilled four holes in the box. A 1/2 inch hole on the front face under the locking clasp for the USB-C cable, and three 5/8 inch holes – 2 on the side and one on the back, to accommodate the rest.

Inside the box I’ve arranged a USB hub connecting:

  • Paladin flash drive
  • External WD hard drive 
  • Keyboard (USB)
  • RF dongle for mouse.
  • Pass through for “universal” laptop power adapter
Cheap wood makes for messy holes.

This box had plenty of space to arrange the components. The laptop power adapter comes in the back of the box and then back out on the side.  The USB connector for the hub is also passed through the side. The cable for the keyboard passes through the front.

The finished set-up

The setup is completed with an Azio Retro Compact keyboard, (with replacement copper-edged keys) and a sort of matching mouse.

When it’s time to image, just sit the laptop on top, connect the USB cable and power, and you’re good to go.

Questions from the Webcast

Recently my session on PowerShell Tools for IR Forensics Collection was re-broadcast by Magnet Forensics. During the event there were a few questions and I thought I’d share my responses here.

If you missed the presentation, just look to the previous post and you’ll find a link for YouTube.

Does the CSIRT script check for sufficient available space for the temp files before running? I’ve run into this issue with KAPE collections that get a lot of event logs.

No it doesn’t. Depending on the artifact collection type, the output sizes can vary greatly.  Once you have a collection script that you want to use as your default, I’d measure what the average size is. In all my collection processes I like to make sure I have 1.5x available free space for what I anticipate collecting.  A WMI ‘check’ could be built into the script to verify the freespace vs. expected collection needs.

Example WMI command for available freespace:

Get-WmiObject -Class Win32_LogicalDisk | ? {$_. DriveType -eq 3} | select DeviceID, {$_.Size /1GB}, {$_.FreeSpace /1GB}

To get the current size of the event logs via WMI:

$WMI = Get-CimInstance -ClassName 'Win32_NTEventlogfile'
$WMI |Format-Table -AutoSize

This will present the available free space on any fixed disks attached to the system.

The best utilization of free space I could come up with was to grab the memory first, compress it, ship it off and then repeat the collection, compression and transfer with KAPE. This minimizes the amount of disk space needed on the remote host. Both processes have a clean-up operation where all local data is deleted from the endpoint once the network transfer has successfully completed.

With memory sizes so big lately, is it possible to configure the script to collect the important artifacts from memory, rather than the entire memory (e.g. process listing, network connections, etc.)?

It would be possible to generate that information on the endpoint using a series of PowerShell commands and write the output to a text file (Get-Process, Get-NetTCPConnection, etc.).  This is certainly useful from an IR perspective, but the only artifact that would be returned back would be the output file. Depending on the circumstances of the investigation you may still need/want the full memory image as evidence.

Do we have the list of artifacts that are being collected here?

In the example presented we’re leveraging the SANS Triage KAPE collection target. The specific collection template used by the CSIRT-Collect script can be adjusted by changing the KAPE command options in the script. You can view the details for any KAPE target by either double-clicking the entry in the KAPE gui, or by viewing the corresponding .tkape file in the program directory (use your text editor of choice).  For the SANS Triage collection, the following artifacts are gathered:

# Event Logs
# Evidence of Execution
        Name: Prefetch
        Name: RecentFileCache
        Name: Amcache
        Name: Amcache transaction files
        Name: Syscache
        Name: Syscache transaction files
        Name: PowerShell Console Log
# File System    
        Name: $MFT
        Name: $LogFile
        Name: $J
        Name: $Max
        Name: $SDS
        Name: $Boot
        Name: $T
# LNK Files and JumpLists       
        Name: Lnk files from Recent
        Comment: Also includes automatic and custom jumplist directories
        Name: Lnk files from Microsoft Office Recent
        Name: Lnk files from Recent (XP)
        Name: Desktop lnk files XP
        Name: Desktop lnk files
        Name: Restore point lnk files XP
# Recycle Bin and Recycler
        Name: $Recycle.Bin
        Name: RECYCLER WinXP
# System Registry Files
        Name: SAM registry transaction files
        Name: SECURITY registry transaction files
        Name: SOFTWARE registry transaction files
        Name: SYSTEM registry transaction files
        Name: SAM registry hive
        Name: SECURITY registry hive
        Name: SOFTWARE registry hive
        Name: SYSTEM registry hive
        Name: RegBack registry transaction files
        Name: SAM registry hive (RegBack)
        Name: SECURITY registry hive (RegBack)
        Name: SOFTWARE registry hive (RegBack)
        Name: SYSTEM registry hive (RegBack)
        Name: SYSTEM registry hive (RegBack)
        Name: System Profile registry hive
        Name: System Profile registry transaction files
        Name: Local Service registry hive
        Name: Local Service registry transaction files
        Name: Network Service registry hive
        Name: Network Service registry transaction files
        Name: System Restore Points Registry Hives (XP)
# User Registry Files
        Name: ntuser.dat registry hive XP
        Name: ntuser.dat registry hive
        Name: ntuser.dat registry transaction files
        Name: ntuser.dat DEFAULT registry hive
        Name: ntuser.dat DEFAULT transaction files
        Name: UsrClass.dat registry hive
        Name: UsrClass.dat registry transaction files
# System Level Artifacts 
# Scheduled Tasks
        Name: at .job
        Name: at SchedLgU.txt
        Name: XML
        Name: SRUM
        Name: Thumbcache DB
# USB Devices Logs
        Name: Setupapi.log XP
        Name: Setupapi.log Win7+
        Name: WindowsIndexSearch
        Name: WBEM
# User Communication        
# Outlook PST and OST files
        Name: PST XP
        Name: OST XP
        Name: PST
        Name: OST
# Skype
        Name: main.db (App <v12)
        Name: skype.db (App +v12)
        Name: main.db XP
        Name: main.db Win7+
        Name: s4l-[username].db (App +v8)
        Name: leveldb (Skype for Desktop +v8)
# Web Browser Artifacts       
        Name: Chrome bookmarks XP
        Name: Chrome Cookies XP
        Name: Chrome Current Session XP
        Name: Chrome Current Tabs XP
        Name: Chrome Favicons XP
        Name: Chrome History XP
        Name: Chrome Last Session XP
        Name: Chrome Last Tabs XP
        Name: Chrome Preferences XP
        Name: Chrome Shortcuts XP
        Name: Chrome Top Sites XP
        Name: Chrome Visited Links XP
        Name: Chrome Web Data XP
        Name: Chrome bookmarks
        Name: Chrome Cookies
        Name: Chrome Current Session
        Name: Chrome Current Tabs
        Name: Chrome Favicons
        Name: Chrome History
        Name: Chrome Last Session
        Name: Chrome Last Tabs
       Name: Chrome Preferences
        Name: Chrome Shortcuts
        Name: Chrome Top Sites
        Name: Chrome Visited Links
        Name: Chrome Web Data
        Name: Chrome Extension Files
        Name: Chrome Extension Files XP
        Name: Edge folder
        Name: WebcacheV01.dat
        Name: Firefox Places
        Name: Firefox Downloads
        Name: Firefox Form history
        Name: Firefox Cookies
        Name: Firefox Signons
        Name: Firefox Webappstore
        Name: Firefox Favicons
        Name: Firefox Addons
        Name: Firefox Search
        Name: Firefox Places (XP)
        Name: Firefox Downloads (XP)   
        Name: Firefox Form history (XP)
        Name: Firefox Cookies (XP)
        Name: Firefox Signons (XP)
        Name: Firefox Webappstore (XP)
        Name: Firefox Favicons (XP)
        Name: Firefox Addons (XP)
        Name: Firefox Search  (XP)
        Name: Index.dat History
        Name: Index.dat History subdirectory
        Name: Index.dat temp internet files
        Name: Index.dat cookies (XP)
        Name: Index.dat UserData (XP)
        Name: Index.dat Office XP
        Name: Index.dat Office
        Name: Local Internet Explorer folder
        Name: Roaming Internet Explorer folder
        Name: IE 9/10 History
        Name: IE 9/10 Cache
        Name: IE 9/10 Cookies
        Name: IE 9/10 Download History
        Name: IE 11 Metadata
        Name: IE 11 Cache
        Name: IE 11 Cookies
# Windows Timeline
        Name: ActivitiesCache.db
        Name: ActivitiesCache.db-shm
        Name: ActivitiesCache.db-wal

Thanks to everyone who participated. If you have further questions feel free to post them here or on the GitHub site