Network Forensics

Foreword xvii Preface xix

Acknowledgments xxv

About the Authors xxvii









Part I: Foundation 1

Chapter 1: Practical Investigative Strategies 3



1.1 Real-World Cases 3

1.2 Footprints 8

1.3 Concepts in Digital Evidence 9

1.4 Challenges Relating to Network Evidence 16

1.5 Network Forensics Investigative Methodology (OSCAR) 17

1.6 Conclusion 22



Chapter 2: Technical Fundamentals 23

2.1 Sources of Network-Based Evidence 23

2.2 Principles of Internetworking 30

2.3 Internet Protocol Suite 35

2.4 Conclusion 44



Chapter 3: Evidence Acquisition 45

3.1 Physical Interception 46

3.2 Traffic Acquisition Software 54

3.3 Active Acquisition 65

3.4 Conclusion 72





Part II: Traffic Analysis 73

Chapter 4: Packet Analysis 75



4.1 Protocol Analysis 76

4.2 Packet Analysis 95

4.3 Flow Analysis 103

4.4 Higher-Layer Traffic Analysis 120

4.5 Conclusion 133

4.6 Case Study: Ann's Rendezvous 135



Chapter 5: Statistical Flow Analysis 159

5.1 Process Overview 160

5.2 Sensors 161

5.3 Flow Record Export Protocols 166

5.4 Collection and Aggregation 168

5.5 Analysis 172

5.6 Conclusion 183

5.7 Case Study: The Curious Mr. X 184



Chapter 6: Wireless: Network Forensics Unplugged 199

6.1 The IEEE Layer 2 Protocol Series 201

6.2 Wireless Access Points (WAPs) 214

6.3 Wireless Traffic Capture and Analysis 219

6.4 Common Attacks 224

6.5 Locating Wireless Devices 229

6.6 Conclusion 235

6.7 Case Study: HackMe, Inc. 236



Chapter 7: Network Intrusion Detection and Analysis 257

7.1 Why Investigate NIDS/NIPS? 258

7.2 Typical NIDS/NIPS Functionality 258

7.3 Modes of Detection 261

7.4 Types of NIDS/NIPSs 262

7.5 NIDS/NIPS Evidence Acquisition 264

7.6 Comprehensive Packet Logging 267

7.7 Snort 268

7.8 Conclusion 275

7.9 Case Study: Inter0ptic Saves the Planet (Part 1 of 2) 276





Part III: Network Devices and Servers 289

Chapter 8: Event Log Aggregation, Correlation, and Analysis 291



8.1 Sources of Logs 292

8.2 Network Log Architecture 306

8.3 Collecting and Analyzing Evidence 311

8.4 Conclusion 317

8.5 Case Study: L0ne Sh4rk's Revenge 318



Chapter 9: Switches, Routers, and Firewalls 335

9.1 Storage Media 336

9.2 Switches 336

9.3 Routers 340

9.4 Firewalls 344

9.5 Interfaces 348

9.6 Logging 352

9.7 Conclusion 355

9.8 Case Study: Ann's Coffee Ring 356



Chapter 10: Web Proxies 369

10.1 Why Investigate Web Proxies? 369

10.2 Web Proxy Functionality 371

10.3 Evidence 375

10.4 Squid 377

10.5 Web Proxy Analysis 381

10.6 Encrypted Web Traffic 392

10.7 Conclusion 401

10.8 Case Study: Inter0ptic Saves the Planet (Part 2 of 2) 402





Part IV: Advanced Topics 421

Chapter 11: Network Tunneling 423



11.1 Tunneling for Functionality 423

11.2 Tunneling for Confidentiality 427

11.3 Covert Tunneling 430

11.4 Conclusion 439

11.5 Case Study: Ann Tunnels Underground 441



Chapter 12: Malware Forensics 461

12.1 Trends in Malware Evolution 462

12.2 Network Behavior of Malware 484

12.3 The Future of Malware and Network Forensics 491

12.4 Case Study: Ann's Aurora 492



Afterword 519



Index 521