CSN08101 Digital Forensics Lecture 10: Windows Registry Module - - PowerPoint PPT Presentation

CSN08101 Digital Forensics

Lecture 10: Windows Registry

Module Leader: Dr Gordon Russell Lecturers: Robert Ludwiniak

Lecture Objectives

• Windows Registry

– Structure – Properties – Examples

• Timeline Analysis
• Web Browsers

– Internet Explorer – FireFox

WINDOWS REGISTRY

Road to Central Depository

• DOS

– config.sys & autoexec.bat

• Windows 3.0

– INI file

• Windows 3.1

– Start of the idea of a central repository

• Windows 95 and beyond

– Establishment and expansion of the registry

Understanding the Windows Registry

• Registry

– A database that stores hardware and software configuration information, network connections, user preferences, and setup information

• For investigative purposes, the Registry can

contain valuable evidence

• To view the Registry, you can use:

– Regedit (Registry Editor) program for Windows 9x systems – Regedt32 for Windows 2000 and XP

Organisation and Terminology

• At the physical level

– Files called hives – Located in: %SYSTEMROOT%\System32\config

• Keys (analogous to folders)
• Values (analogous to files)
• Hierarchy:

– Hives

• Keys

– Values

Hives

Key Value

Hive Properties

• HKEY_USERS – all loaded user data
• HKEY_CURRENT_USER – currently logged on user

(NTUSER.DAT)

• HKEY_LOCAL_MACHINE – array of software and

hardware settings

• HKEY_CURRENT_CONFIG – hardware and software

settings at start-up

• HKEY_CLASSES_ROOT – contains information about

application needs to be used to open files

File Locations and Purpose

Windows 7 Root Keys Windows 7 Root Keys

Registry: A Wealth of Information

Information that can be recovered include:

– System Configuration – Devices on the System – User Names – Personal Settings and Browser Preferences – Web Browsing Activity – Files Opened – Programs Executed – Passwords

Forensic Analysis - Hardware

Windows Security and Relative ID

• The Windows Registry utilizes a alphanumeric

combination to uniquely identify a security principal or security group.

• The Security ID (SID) is used to identify the

computer system.

• The Relative ID (RID) is used to identity the

specific user on the computer system.

• The SID appears as:

– S-1-5-21-927890586-3685698554-67682326-1005

Forensic Analysis – User ID

• SID (security identifier)

– Well-known SIDs

• SID: S-1-0

Name: Null Authority

• SID: S-1-5-2 Name: Network

– S-1-5-21-2553256115-2633344321-4076599324-1006

• S

string is SID

• 1

revision number

• 5

authority level (from 0 to 5)

• 21-2553256115-2633344321-4076599324 - domain or local

computer identifier

• 1006 RID – Relative identifier
• Local SAM resolves SID for locally authenticated

users (not domain users)

– Use recycle bin to check for owners

Forensic Analysis - Software

Forensics Analysis: NTUSER.DAT

• Internet Explorer

– IE auto logon and password – IE search terms – IE settings – Typed URLs – Auto-complete passwords

Forensics Analysis - NTUSER.DAT IE explorer Typed URLs

Forensic Analysis – MRU List

A “Most Recently Used List” contains entries made due to specific actions performed by the user. There are numerous MRU list locations throughout various Registry keys. These lists are maintained in case the user returns to them in the future. Essentially, their function is similar to how the history and cookies act in a web browser.

Forensic Analysis – Last Opened Application in Windows

Forensic Analysis – USB Devices

RegRipper

The RegRipper is an open-source application for extracting, correlating, and displaying specific information from Registry hive files from the Windows NT (2000, XP, 2003, Vista and 7) family of operating systems.

TIMELINE ANALYSIS

System Time

• Determined by booting into the BIOS and

comparing it with an external source

– Radio Signal Clock or Time Server

• CMOS Clock

– Complementary Metal Oxide Semiconductor Chip (CMOS) – Accessed by most OS to determine the time

Operating System Time

• Embedded within the file system or high level file

metadata

• Will take into account local time (or not!)
• Can confuse an investigation depending on tool

configuration and time zone

• Will ask for the time from the BIOS CMOS

Program Time

• Programs will ask for the time from the OS
• They can bypass the OS and ask for the time

directly from the BIOS

• It’s important to check and understand where a

program gets its time details from.

OS Time – DOS

• MS DOS time/date Format (FAT File System)
• Stored as local time
• Used for MAC information
• 32 Bit Structure

– Seconds (5 bits from offset 0) – Minutes (6 bits from offset 5) – Hours (5 bits from offset 11) – Days (5 bits from offset 16) – Months (4 bits from offset 21) – Years (7 bits from offset 25)

64 Bit Windows FILE TIME

• 64 bit number measuring the number of 100ns

intervals since 00:00:00, 1st Jan, 1601

– 58,000 year lifetime

• Stored in the MFT – MAC

Unix Time

• 32-bit value
• Number of seconds elapsed since

– 1st January 1970, 00:00:00 GMT

• Limit

– Monday, December 2nd, 2030 and 19:42:58 GMT

Local and UTC time translation

• Coordinated Universal Time (UTC)

– Effectively the same as GMT

• Modern OS calculate the difference

between local time and UTC and store the time/date as UTC

Local Time vs UTC

• 00 DB A2 F7 5C B1 C5 01 (Localtime)

– 127703177299680000

• 00 7B B4 7E 7E B1 C5 01 (GMT)

– 127703321299680000

• Difference:

– 144,000,000,000

• Verify:

– 144,000,000,000 * 0.0000001 = 14,400 – 100 ns = 10 millionth of a second – 3,600 s in 1 hour. 14,400 in 4 hours – = 4 hours

Time and the Registry

• ME/XP/Vista/Windows 7

– HKEY_Local_Machine/System/Current ControlSet/Control/TimeZoneInformation/Bias

• ActiveTimeBias

– Amount of time (+ or -) to add to UTC – StandardName - Time Zone

GMT

No adjustment required

EST

WEB BROWSERS

Browsers

• The major browsers (most to least-used):

– Internet Explorer – 61.58% – Mozilla Firefox – 24.23% – Everything else! – 14.19%

Hitslink.com – February 2010

Internet Explorer - storage

Stores files used in displaying web pages (cache), tracking pages visited (history) and automatic identification / authentication (cookies, credentials)

• Viewed pages will retrieve its page code and embedded files (such

as graphics) from the hard drive rather than the server, so the page loads faster (cache)

• Able to see a record of recently visited pages (history)
• No sign in again at sites that require it, or to specify preferences

again (cookies and credentials). Also cookies are used by the visited site and other sites to track web browsing, which is a privacy discussion on its own.

IE – Browsing History With Cache Files

• For the subject's browsing history (index.dat

and the cache files themselves – in subdirectories), use Windows Explorer to look in

C:\Documents and Settings\<subject User’s ID>\Local Settings\Temporary Internet Files\Content.IE5\ C:\Users\<subject User’sID>\AppData\Local\Microsoft\ Windows\Temporary Internet Files\Content.IE5

IE – Browsing History Without Cache Files

• For the subject's browsing history (index.dat

without the cache files), use a browser (NOT Windows Explorer) or command prompt to look in

C:\Documents and Settings\<subject User’s ID>\Local Settings\History\History.IE5\ Daily history: MSHist01(start)YYYYMMDD(end)YYYYMMDD Weekly history: MSHist01(start)YYYYMMDD(end)YYYYMMDD

IE – Index.dat In Depth - Header

IE – Index.dat In Depth - Activity Record

IE – What If The Subject Clears The Cache?

• In IE6, when you select Delete Files, the cache

files are deleted from the hard drive, but the entries in index.dat are marked “free” and NOT removed!

• IE7 & 8 is more thorough – Selecting Delete

Files removes both the files and the entries in index.dat (although you can restore the files themselves as they are not overwritten)

IE8 – What If The subject uses “InPrivate Browsing”?

• InPrivate does make the forensic examiner’s job more

difficult by not recording items such as typed addresses, visited links, and forms, queries and passwords entered, including not recording the “host records” (URLS) in index.dat. It also deletes the contents of Temporary Internet Files when the “subject” exits the browsing session.

• However, items (such as the cached filename and page

header information) are still dutifully written to index.dat, making it still possible for an investigator to infer where the “subject” has been surfing.

Internet Explorer – Cookies

• For cookies saved on the subject's hard drive

(individual cookie text files), use Windows Explorer to look in C:\Documents and Settings\<subject User’s ID>\Cookies\

IE 6 and Before – Identification / Authentication

• Stores encrypted userIDs and passwords

(AutoComplete) in HKCU\Software\Microsoft\Internet Explorer\IntelliForms\ SPW, and web addresses in HKLM\Software\Microsoft\Protected Storage System Provider\<subject’s user ID>

IE 7 & 8 – Identification / Authentication

• Stores encrypted userIDs and passwords

(AutoComplete) in

HKCU\Software\Microsoft\Internet Explorer\IntelliForms\Storage2

• Encryption has been improved

Mandiant Web Historian - Overview

• A tool that allows you to take a given

index.dat file and parse it into a readable / exportable format

• Available at

http://www.mandiant.com/webhistorian.htm

Mandiant Web Historian – History Report

Pasco

• Pasco is another tool for analysis of the

index.dat files, but this one also runs on Unix, which is another environment where you may be running other forensics tools

• Does basically the same operation as Web

Historian, outputting to delimited text files that can be imported elsewhere

Pasco - History with Cache

Galleta - Cookie analysis

• From the command line (Unix or

Windows): galleta <option> (filename)

• Option: -t (column delimiter – defaults to

tab)

• Use > to redirect output into a file

IE PassView - Stored Credentials

• IE PassView reads the stored Internet Explorer

credentials from the Windows Registry and returns the website, userID and password in columnar format

• Note that this will obtain the user credentials, but

not other autocomplete information such as form fields

• You will have to run it on the subject's computer –

not a very good idea, so create a (forensic) working copy and run it from there

Firefox - Overview

• Open source web browser
• Evolved from the Netscape Navigator web

browser

• Support for images, frames, SSL and javascript
• Full disk cache support

Firefox – File Locations

• Firefox stores its history, downloads, form fields,

cookies, and Identification / Authentication files in the same location: C:\Documents and Settings\<subject User’s ID>\Application Data\Mozilla \Firefox\Profiles\<seemingly random characters>.default\ (Windows XP) or C:\Users\<subject User’s ID>\AppData\Local\Mozilla \Firefox\Profiles\<seemingly random characters>.default\ (Windows Vista, 7 and 2008)

Firefox – File Locations (2)

• Firefox stores its cache files in a different location:

C:\Documents and Settings\<subject User’s ID>\Local Settings\Application Data\Mozilla \Firefox\Profiles\<seemingly random characters>.default\Cache\ (Windows XP) or C:\Users\<subject User’s ID>\AppData\Local\Mozilla \Firefox\Profiles\<seemingly random characters>.default\Cache\ (Windows Vista, 7)

SQLite Library

• Software library that implements a transactional

SQL Database Engine

• Used by Firefox to store information in the files

we discussed before

• Unlike with earlier Firefox versions, the text in

SQLite format can be read easily within Firefox

Firefox– Viewing (Almost) Without Tools

Mandiant Web Historian – Firefox

Firefox Cache – Inside The Files

• On Firefox, the cache information is stored

across 3 types of files: one (1) cache map file, three (3) cache block files, and as many additional cache data files as required to store additional cache data

Firefox – What If The subject Clears The Cache?

• In Firefox, the situation is skewed much more in

favor of the subject. Going to Tools and selecting Clear Private Data deletes not only the cache files, but handily removes the cache map and cache block files, so tying the files (assuming you could recover them) to the cache map and blocks becomes quite a bit more difficult

Cache View - Firefox

MozillaCookiesView - Firefox

FireMaster – Stored Credentials

• Firefox gives you the option to save your often-

used userIDs and passwords that you utilize to access websites

• Unfortunately for the forensic investigator, the

subject may specify a Master password, which prevents access to all the other passwords

• FireMaster cracks this master password, allowing

you to access the password list in the browser or via FirePassword

FirePassword – Stored Credentials

• Used with or without the Master Password

(depending on if it’s been set) to see the websites your subject visited and the userIDs and passwords s/he used to get in

• Much quicker than FireMaster, as you either

don’t have a Master Password or have already specified it!

ANY QUESTIONS ...