Tag: PowerShell; DFIR; Github; Presentations

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 https://github.com/dwmetz/CSIRT-Collect