CSF 3403 Digital Forensics & Investigation PDF

CSF 3403 - Digital Forensics and Investigation Chapter 6: Current Digital Forensics Tools 1  2 Learning Outcomes CLO1: Demonstrate an understanding of digit...

CSF 3403 - Digital Forensics and Investigation Chapter 6: Current Digital Forensics Tools 1  2 Learning Outcomes CLO1: Demonstrate an understanding of digital forensics principles, techniques, and legal considerations essential for the collection and investigation of digital evidence. CLO2: Apply proper techniques and tools to acquire and preserve digital evidence from various sources meeting legal standards. CLO3 :Investigate digital crimes and incidents using digital forensic tools producing detailed forensic reports. CLO4: Apply forensic techniques to assess digital artifacts from diverse sources and in various formats.  3 Delivery Outline W1-2: CH1: Understanding The Digital Forensics Profession and Investigations (CLO 1) CH2: Under standing Forensics Lab Requirements (CLO 1) W3: CH6 - Current Digital Forensics Tools (CLO1) W4: CH4 - Processing Crime and Incident Scenes (CLO1,2) W5-6: CH3 - Data Acquisition (CLO2) W7: CH5 - Working with Windows and CLI Systems (CLO3) As_Exam: 25% W8: CH7 – Linux and Macintosh File Systems (CLO3) W9: CH9 – Digital Forensics Analysis and Validation (CLO4) W10: CH8 - Recovering Graphics Files (CLO4) CH11 - E-mail and Social Media Investigations (CLO4) W11: CH14 - Report Writing for High-Tech Investigations (CLO4) W12: Practical Test: PCQ_ACE Exam 15% W13: CH12 - Mobile Device Forensics and the internet of anything (CLO4) W14: CH13 - Cloud Forensics (CLO4) By: Ali Abu Romman  Chapter 6: Current Digital Forensics Tools (CLO1) By: Ali Abu Romman  5 Objectives Upon completing this chapter, students will be able to: Explain how to evaluate needs for digital forensics tools Describe available digital forensics software tools List some considerations for digital forensics hardware tools Describe methods for validating and testing forensics tools Section 1 Evaluating Digital Forensics Tool Needs  7 Evaluating Digital Forensics Tool Needs Consider open-source tools; the best value for as many features as possible Questions to ask when evaluating tools: On which OS does the forensics tool run? Is the tool multipurpose? Can the tool analyze more than one file system? Can a scripting language be used with the tool to automate repetitive functions and tasks? Does it have automated features? What is the vendor’s reputation for providing product support?  8 Types of Digital Forensics Tools Hardware forensic tools Range from simple, single-purpose components to complete computer systems and servers Software forensic tools Types Command-line applications GUI applications Commonly used to copy data from a suspect’s disk drive to an image file  9 Tasks Performed by Digital Forensics Tools Follow guidelines set up by NIST’s Computer Forensics Tool Testing (CFTT) program ISO standard 27037 states: Digital Evidence First Responders (DEFRs) should use validated tools Five major categories: Acquisition Validation and verification Extraction Reconstruction Reporting  10 1. Acquisition Making a copy of the original drive Acquisition subfunctions: Physical data copy Logical data copy Data acquisition format Command-line acquisition GUI acquisition Remote, live, and memory acquisitions  11 1. Acquisition Two types of data-copying methods are used in software acquisitions: Physical copying of the entire drive Logical copying of a disk partition The formats for disk acquisitions vary From raw data to vendor-specific proprietary You can view a raw image file’s contents with any hexadecimal editor Creating smaller segmented files is a typical feature in vendor acquisition tools Remote acquisition of files is common in larger organizations Popular tools, such as AccessData and EnCase, can do remote acquisitions of forensics drive images on a network  12 2. Validation and Verification Validation A way to confirm that a tool is functioning as intended Verification Proves that two sets of data are identical by calculating hash values A related process is filtering, which involves sorting and searching through investigation findings to separate good data and suspicious data. Subfunctions Hashing CRC-32, MD5, SHA-1 (Secure Hash Algorithms) Filtering Based on hash value sets Analyzing file headers Discriminate files based on their types National Software Reference Library (NSRL) has compiled a list of known file hashes For a variety of OSs, applications, and images  13 2. Validation and Verification Validation and discrimination Many computer forensics programs include a list of common header values With this information, you can see whether a file extension is incorrect for the file type Most forensics tools can identify header values  14 3. Extraction Recovery task in a digital investigation Most challenging of all tasks to master Recovering data I Subfunctions of extraction Data viewing Keyword searching Decompressing or uncompressing Carving Decrypting Bookmarking or tagging Keyword search speeds up analysis for investigators s the first step in analyzing an investigation’s data  15 3. Extraction From an investigation perspective, encrypted files and systems are a problem Many password recovery tools have a feature for generating potential password lists For a password dictionary attack If a password dictionary attack fails, you can run a brute-force attack  16 4. Reconstruction Re-create a suspect drive to show what happened during a crime or an incident Methods of reconstruction Disk-to-disk copy Partition-to-partition copy Image-to-disk copy Image-to-partition copy Disk-to-image copy Rebuilding files from data runs and carving  17 4. Reconstruction Re-create a suspect drive to show what happened during a crime or an incident Methods of reconstruction Disk-to-disk copy Partition-to-partition copy Image-to-disk copy Image-to-partition copy Disk-to-image copy Rebuilding files from data runs and carving  18 4. Reconstruction To re-create an image of a suspect drive Copy an image to another location, such as a partition, a physical disk, or a virtual machine Simplest method is to use a tool that makes a direct disk-to-image copy Examples of disk-to-image copy tools: Linux dd command ProDiscover Voom Technologies Shadow Drive  19 5. Reporting To perform a forensics disk analysis and examination, you need to create a report Subfunctions of reporting Bookmarking or tagging Log reports Timelines Report generator Use this information when producing a final report for your investigation  20 5. Reporting Considerations Flexibility Reliability Future expandability Create a software library containing older versions of forensics utilities, OSs, and other programs Section 2 Digital Forensics Software/Hardware Tools  22 Command-line Forensics Tools The following sections explore some options for command-line and GUI tools in both Windows and Linux: The first tools that analyzed and extracted data from floppy disks and hard disks were MS-DOS tools for IBM PC file systems Norton DiskEdit One of the first MS-DOS tools used for computer investigations Command-line tools require few system resources Designed to run in minimal configurations  23 Command-line Forensics Tools UNIX has been mostly replaced by Linux You might still encounter systems running UNIX Linux platforms have become more popular with home and business end users SMART Designed to be installed on numerous Linux versions Can analyze a variety of file systems with SMART Many plug-in utilities are included with SMART Another useful option in SMART is its hex viewer  24 Command-line Forensics Tools Helix 3 One of the easiest suites to use You can load it on a live Windows system Loads as a bootable Linux OS from a cold boot **Some international courts have not accepted live acquisitions as a valid forensics practice Kali Linux Formerly known as BackTrack Includes a variety of tools and has an easy-to-use KDE interface  25 Other GUI Forensics Tools GUI forensics tools can simplify digital forensics investigations Have also simplified training for beginning examiners Most of them are put together as suites of tools Advantages Ease of use Multitasking No need for learning older OSs  26 Other GUI Forensics Tools Disadvantages Excessive resource requirements Produce inconsistent results Create tool dependencies Investigators’ may want to use only one tool Should be familiar with more than one type of tool  27 Digital Forensics Hardware Tools Technology changes rapidly Hardware eventually fails Schedule equipment replacements periodically When planning your budget consider: Amount of time you expect the forensic workstation to be running Failures Consultant and vendor fees Anticipate equipment replacement Carefully consider what you need Categories Stationary workstation Portable workstation Lightweight workstation Balance what you need and what your system can handle Remember that RAM and storage need updating as technology advances  28 Forensic Workstations Carefully consider what you need Categories Stationary workstation Portable workstation Lightweight workstation Balance what you need and what your system can handle Remember that RAM and storage need updating as technology advances Police agency labs Need many options Use several PC configurations Keep a hardware library in addition to your software library Private corporation labs Handle only system types used in the organization  29 Forensic Workstations Building a forensic workstation is not as difficult as it sounds Advantages Customized to your needs Save money Disadvantages Hard to find support for problems Can become expensive if careless Also need to identify what you intend to analyze  30 Using a Write-Blocker Write-blocker Prevents data writes to a hard disk Software-enabled blockers Typically run in a shell mode (Windows CLI) Example: PD Block from Digital Intelligence Hardware options Ideal for GUI forensic tools Act as a bridge between the suspect drive and the forensic workstation You can navigate to the blocked drive with any application Discards the written data For the OS the data copy is successful Connecting technologies FireWire USB 2.0 and 3.0 SATA, PATA, and SCSI controllers  31 Validating and Testing Forensic Software It is important to make sure the evidence you recover and analyze can be admitted in court You must test and validate your software to prevent damaging the evidence NIST publishes articles, provides tools, and creates procedures for testing/validating forensics software Computer Forensics Tool Testing (CFTT) project Manages research on forensics tools NIST has created criteria for testing forensics tools based on: Standard testing methods ISO 17025 criteria for testing items that have no current standards  32 Using Validation Protocols Always verify your results by performing the same tasks with other similar forensics tools Use at least two tools Retrieving and examination Verification Understand how forensics tools work One way to compare results and verify a new tool is by using a disk editor Such as Hex Workshop or WinHex Disk editors do not have a flashy interface, however they: Are reliable tools Can access raw data Digital Forensics Examination Protocol Perform the investigation with a GUI tool Verify your results with a disk editor Compare hash values obtained with both tools  33 Using Validation Protocols Digital Forensics Tool Upgrade Protocol Test New releases OS patches and upgrades If you find a problem, report it to forensics tool vendor Do not use the forensics tool until the problem has been fixed Use a test hard disk for validation purposes Check the Web for new editions, updates, patches, and validation tests for your tools  34 Summary Consult your business plan to get the best hardware and software Computer forensics tools functions Acquisition Validation and verification Extraction Reconstruction Reporting Maintain a software library on your lab Computer Forensics tools types Software Hardware Forensics software Command-line GUI  35 Delivery Outline W1-2: CH1: Understanding The Digital Forensics Profession and Investigations (CLO 1) CH2: Under standing Forensics Lab Requirements (CLO 1) W3: CH6 - Current Digital Forensics Tools (CLO1) W4: CH4 - Processing Crime and Incident Scenes (CLO1,2) W5-6: CH3 - Data Acquisition (CLO2) W7: CH5 - Working with Windows and CLI Systems (CLO3) As_Exam: 25% W8: CH7 – Linux and Macintosh File Systems (CLO3) W9: CH9 – Digital Forensics Analysis and Validation (CLO4) W10: CH8 - Recovering Graphics Files (CLO4) CH11 - E-mail and Social Media Investigations (CLO4) W11: CH14 - Report Writing for High-Tech Investigations (CLO4) W12: Practical Test: PCQ_ACE Exam 15% W13: CH12 - Mobile Device Forensics and the internet of anything (CLO4) W14: CH13 - Cloud Forensics (CLO4)  CIS 2103 800 MyHCT (800 69428) www.hct.ac.ae