Digital Forensics

Digital Forensics

Dr. Bhavani Thuraisingham

The University of Texas at Dallas

Lecture #5

Technology and Services

September 9, 2009

Review of Lectures

Part 1 of the Course

- Reference: Part 1 of the Book + Links given in Lectures

- Lecture 1: Introduction to Digital Forensics

- Lecture 2: Background on Cyber Security

- Lecture 3: Data Recovery and Evidence Collection

- Lecture 4: Malicious Code Detection: How do you detect that the problem has occurred?

- Lecture 5: Forensics Technologies and Services Part 2 of the Course

- Part 2 of the Book

- Lecture 6: Data Acquisition Details (September 14, 2009)

Assignment #1

Text Book

- Hands-on Project 2.1

- Hands-on Project 2.2

- Chapter 2

- Page 68-69

- Due: Wednesday September 23, 2009

Outline

Forensics Technologies

- Forensics Technology Military, Law Enforcement, Business Forensics

- Forensics Techniques Finding Hidden Data, Spyware, Encryption, Data

Protection, Tracing, Data Mining

- Security Technologies Wireless, Firewalls, Biometrics

Services

- Cyber crime, Cyber detective, Risk Managemen, Investigative services, Process improvement

Introduction

Digital forensics includes computer forensics and network forensics

Computer forencis

- gathers evidence from computer media seized at crime scene

- Issues involve imaging storage media, recovering deleted files, searching slack and free space, preserving the collected information for litigation

Network forencis

- Analysis of computer network intrusion evidence

Military Forensics

CFX-2000: Computer Forencis Experiment 2000

- Information Directorate (AFRL) partnership with NIJ/NLECTC

- Hypothesis: possible to determine the motives, intent, targets, sophistication, identity and location of cyber terrorists by deploying an integrated forensics analysis framework

- Tools included commercial products and research prototypes

- http://www.afrlhorizons.com/Briefs/June01/IF0016.html

- http://rand.org/pubs/monograph_reports/MR1349/MR1349.appb.pdf

Law Enforcement Forensics

Commonly examined systems: Windows NT, Windows 2000, XP and 2003

Preserving evidence

- Mirror image backups: Safe Back technology from New Technologies Inc.

Tools to handle

- Trojan Horse programs / File slacks

- Data Hiding Techniques AnaDisk analyzes diskettes COPYQM duplicates diskettes

- E-Commerce investigation: Net Threat Analyzer

- Text search: TextSearch Plus tool

- Fuzzy logic/data mining tools to identify unknown text Intelligent Forensics Filter

Business Forensics

Remote monitoring of target computers

- Data Interception by Remote Transmission (DIRT) from Codex Data Systems

Creating trackable electronic documents Theft recovery software for laptops and PCs

- PC Phonehome tool

- RFID technology

Forensics Techniques

Techniques for finding, preserving and preparing evidence Finding evidence is a complex process as the forensic expert

has to determine where the evidence resides

- Evidence may be in files, evidence may be in disks, evidence may be on paper. Need to track all types of evidence

Preserving evidence includes ensuring that the evidence is not tampered with

- Involves pre-incident planning and training in incident discovery procedures’ If the machine is turned on, leave it on; do not run programs on that particular computer

Preparing evidence will include data recovery, documentation, etc.

Finding Hidden Data

When files are deleted, usually they can be recovered The files are marked as deleted, but they are still residing in

the disk until they are overwritten Files may also be hidden in different parts of the disk The challenge is to piece the different part of the file together

to recover the original file There is research on using statistical methods for file

recovery http://www.cramsession.com/articles/files/finding-hidden-data

---how-9172003-1401.asp http://www.devtarget.org/downloads/ca616-seufert-

wolfgarten-assignment2.pdf

Spyware/Adware

Spyware is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent.

- http://en.wikipedia.org/wiki/Spyware Spyware is mostly advertising supported software (adware) Shareware authors place ads from media company and get a

piece if the revenue PC surveillance tools that allow a user to nominate computer

activity

- Keystroke capture, snapshots, email logging, chats etc. Privacy concerns with spyware

Encryption

Popular Encryption techniques

- Public key/ Private Key Owner of the data encrypts with the public key of the

receiver; Receiver decrypts with his private key In some cases owner may encrypt with his private key for

multiple receiver. Receiver will decrypt with the owner’s public key

Merkle Hash is a popular method to hash documents; one way hash function

Challenge is to generate unique keys Issues: Trusted authority to generate keys and credentials

Internet/Web Tracing

Where has the email come from

- Check IP address

- Sender may use fake address by changing fields; sending server may not check this and so the mail is sent

Tracing web activity Who has logged into the system say from a public web site

and modified accounts and grades? Web/email tracking tools

- http://www.cryer.co.uk/resources/websitetracking.htm

- http://www.visualware.com/resources/tutorials/email.html

Wireless Technology Forensics Forensic Examination of a RIM (BlackBerry) Wireless Device

http://www.rh-law.com/ediscovery/Blackberry.pdf

- “There are two types of RIM devices within each model class. The Exchange Edition is meant

for use in a corporate environment while the Internet Edition works with standard POP email

accounts. The Exchange Edition employs Triple-DES encryption to send and receive but the

Internet Edition communicates in clear text. Neither employs an encrypted files system”

Relevance of RIM forensics

- “The RIM device shares the same evidentiary value as any other Personal Digital Assistant

(PDA). As the investigator may suspect of most file systems, a delete is by no means a total

removal of data on the device. However, the RIM’s always-on, wireless push technology adds

a unique dimension to forensic examination. Changing and updating data no longer requires a

desktop synchronization. In fact, a RIM device does not need a cradle or desktop connection

to be useful. The more time a PDA spends with its owner, the greater the chance is that it will

more accurately reflect and tell a story about that person. Thus, the RIM’s currently

unsurpassed portability is the examiner’s greatest ally”

Wireless Technology Forensics - 2 The Hardware

- The RIM device is designed around an Intel 32-bit i386 processor, a low power

embedded version of the same processor that used to power a desktop PC. Each unit

has 512 KB of SRAM and 4 or 5 MB of Flash RAM, depending on the model. The RIM’s

SRAM is analogous to the RAM on a desktop and the Flash memory is the “disk space”

used to store the Operating System (OS), applications, and the file system. The RIM’s

OS is a single executable named PAGER.EXE and the applications are DLL’s.

Toolbox

- BlackBerry Desktop Software available free at www.blackberry.com; BlackBerry C++

Software Development Kit v2.1 available free at www.blackberry.com; • Hex editor; • Text

editor; • AA batteries; • Spare BlackBerry Cradles

- The examination PC should meet the minimum requirements for the BlackBerry Software

Development Kit (SDK) and have two available external 9-pin RS232 serial ports. Disk

space required for evidence gathering is minimal: space equal to the amount of Flash

RAM in the RIM units being investigated.

Firewall Forensics http://www.linuxsecurity.com/resource_files/firewalls/firewall-

seen.html Analyzing firewall logs, especially what port numbers etc.

mean?. May use this information to help figure out what hackers are up to.

- What does destination port number ZZZZ mean?

- What does this ICMP info mean?

- What do these IP addresses indicate?

- Stuff doesn't work

- What are some typical signatures of well-known programs?

- What do these other logs mean?

- How do I configure filters?

- Packet Zen

- What's the deal with NetBIOS (UDP port 137)?

Biometrics Forensics: Richard Vorder Bruegge

http://www.biometrics.org/bc2004/Bios/vorderbruegge_bio_OK.pdf

http://www.biometrics.org/bc2004/Presentations/Conference/2%20Tuesday%20September%2021/Tue_Ballroom%20B/1%20DOJ%20Session/Vorderbruegge_Presentation.pdf

It often happens that people confuse biometrics and forensics. After all, television and movies make it look like automated biometrics databases can be used to identify and convict people all the time. Isn't that what forensics is all about? Unfortunately, this can have an adverse affect on the development of forensic tools which utilize biometric features, because those in position to make funding decisions may not understand the distinction between the two. This presentation will attempt to provide the audience with a better understanding of the relationship between biometrics and forensics from the standpoint of a forensic scientist.

Biometrics Forensics: Richard Vorder Bruegge

Advances in the field of biometrics offers great potential for the field of forensics. Biometric databases offer the promise of enabling law enforcement and the intelligence community to rapidly identify questioned individuals if they are present in the queried database. However, obtaining a "hit" in a biometric database is a far cry from an identification in the world of forensic science. The standard of proof to which forensic scientists in the United States are held is "beyond a reasonable doubt". That "reasonable doubt" criteria, coupled with standards for scientific and technical evidence elucidated in the "Daubert" and "Kumho Tire" cases, require that conclusions offered by forensic scientists be supported at beyond that offered by current biometric systems, particularly in the field of facial recognition.

http://forensic-evidence.com/site/ID/ID_prime_qd.html Reviewing Court Approves of Fingerprint Admissibility

Technologies: Conclusion Two types of forensics: Computer forencis and network forensics Computer forencis is mainly about file system forencis; network

forensics is about detecting intrusions and connecting with hackers/terrorists

Various techniques are being developed for Military forensics, Law enforcement forencis, Business forensics; not mutually exclusive

Difference tools for differing systems Systems include operating systems, database systems, networks,

middleware, wireless systems, firewalls, biometrics Biometrics systems may be compromised; however biometrics may

be used as evidence Data mining/analysis being used for forensics

- http://eprints.qut.edu.au/archive/00002274/01/2274.pdf (Image mining for digital forensics)

Types of Computer Forensics Systems Internet Security Systems Intrusion Detection Systems Firewall Security Systems Storage Area Network Security Systems Network disaster recovery systems Public key infrastructure systems Wireless network security systems Satellite encryption security systems Instant Messaging Security Systems Net privacy systems Identity management security systems Identify theft prevention systems Biometric security systems Homeland security systems

Cyber Crime

Financial Fraud Sabotage of Data or Networks Theft of Proprietary Information System Penetration from the outside and denial of service Unauthorized access by insiders and employee misuse of

Internet access privileges: Insider threat Malicious code (e.g., Virus)

Cyber Detective

Forensics investigators

- detect the extent f security breach,

- recover lost data,

- determine how an intruder got past the security mechanisms,

- and possibly identify the culprit Legal issues

- Admissibility of digital evidence in court

- Laws lag technology

- Theft: A person must permanently deprive the victim of property: does this apply to cyber theft?

Risk Management Risk management

- is the human activity which integrates recognition of risk, risk assessment, developing strategies to manage it, and mitigation of risk using managerial resources.

- The strategies include transferring the risk to another party, avoiding the risk, reducing the negative effect of the risk, and accepting some or all of the consequences of a particular risk.

- http://en.wikipedia.org/wiki/Risk_management Risk management for Computer Forensics

- Effective IT and staff policies

- Use of state of the art Vendor tools

- Effective procedures

Forensic Services

Forensics Incident Response Evidence Collection Forensic Analysis Expert witness Forensic litigation and insurance claims support Training Process improvement

Investigative services examples

Intrusion detection service

- Installing technical safeguards to spot network intruders or detect denial of service attacks at e-commerce servers

Digital evidence collection

- Identify all devices that may contain evidence

- Quarantine all in-house computers

- Court orders to preserver and collect evidence

Process Improvement: Tools

Dig –x/nslookup Whois Ping Traceroute Finger Anonymous surfing USENET Need to integrate the processes

Links

http://www.compforensics.com/ http://www.computer-forensic.com/faqs.html http://www.cfsiusa.com/

- Dallas, TX http://www.evestigate.com/ http://www.digitaldataforensics.com/ http://www.databankservices.com/

- Austin, TX http://www.vogon-international.com/computer-

forensics/ http://www.vogon.co.uk/ http://www.forensiccomputerservice.com/