380 likes | 679 Views
Forensics. Learning Objectives. Definition of Forensics Be able to understand process in building legally sound case Identify forensic capabilities you will need in a typical corporate environment. Definition. Forensic:
E N D
Learning Objectives • Definition of Forensics • Be able to understand process in building legally sound case • Identify forensic capabilities you will need in a typical corporate environment
Definition • Forensic: • “…a characteristic of evidence that satisfies its suitability for admission as fact and its ability to persuade based upon proof (or high statistical confidence).” • The aim of forensic science is: • “…to demonstrate how digital evidence can be used to reconstruct a crime or incident, identify suspects, apprehend the guilty, defend the innocent, and understand criminal motivations.” Ref: Casey, “Digital Evidence and Computer Crime”, 2nd ed., section 1.6, p20.
The Goal of Forensics • Forensics seeks to provide an accurate representation of extracted data: find out the truth • How was it lost? • What was lost? • What are my obligations concerning the loss?
Forensics vs. Incident Handling • Closely tied together, but different • Data collection starts immediately as a part of incident handling • Data analysis is not a part of incident handling • The incident can sometimes be closed before forensic analysis is complete
Legally Sound Data Collection • Security in Computing, chapter 9.5 • Goals • Build a solid case • Find out what was lost • Find out the truth
Privacy Issues • Generally apply principles from the physical world • Can you: • Read my mail? • Listen to my phone call? • Obtain a copy of my phone bill?
Applicable Statutes • Computer fraud and abuse act, 18USC1030 • Protects against unauthorized access (privacy intrusion)
Applicable Statutes (2) • Federal Wiretap Act (18USC2510-22) • Protect data in transit (real-time) • Three key exceptions: • Provider • Consent • Trespasser
Applicable Statutes (3) • Pen Registers and Trap and Trace Devices, 18USC3121-27 • Pen/trap or Trap & Trace • Real-time collection of header information • What is header information?
Applicable Statutes (4) • The Electronics Communications Privacy Act • ECPA • Protects stored data (both headers and content) • What is the difference between read voice mail and unread voice mail?
Applicable Statutes (5) • Patriot Act • Patches up ECPA and others by clearly defining how Law Enforcement can gather data • Renewed in early 2006 with only minor changes
Applicable Statutes (6) • Other traditional statutes may apply • Trade secrets • Harassment • Copyright Infringement
Applicable Statutes (7) • Summary • Headers vs. content • Real-time vs. stored • Complex and changing • Acting under the cover of law • What information can you share with law enforcement?
Employee Rights • Bannering • What should be in an acceptable use policy? • Is bannering sufficient? • Pseudo-employees • Contractors • Consultants • Temps • Interns • Auditors • …
Case Study(1) • Acceptable Use Violation • Indications • Initial course of action • What are you certain you can do? • What are you certain you can not do? • Where do you go forguidance?
Regulatory Issues • Gramm-Leach-Bliley Act of 1999 (GLBA) • Protect consumer personal financial data • Health Insurance Portability and Accountability Act of 1996 (HIPAA) • Federal privacy protection for individually identifiable health information • Public Firms • SEC, NASD requirements for document retention
Data Collection • Make copies of everything • Only work on copies • Create MD5 checksums
Data Collection Toolkit • Software • Static binaries • Linux-based • Hardware • Cables, adapters • Very large drives • Chain of custody forms • Calibration procedure
Case Study(2) • Bringing the evidence to court • Do you really have to explain an MD5 checksum of a hard drive to the jurors?
Data on the Computer • In files • In log files • Browser history • Windows prefetch area • Slack space • Open network connections • Virtual memory • Physical memory • Network traces Lost when machine is powered off Lost if you wait too long Real-time only
Data on Other Computers • Infrastructure logs • Web servers, mail servers • Archival systems • Network / Firewall logs • Intrusion detection systems • Everything that logs
Data in Unexpected Places • Anti-virus alerts, real-time anti-virus scans • License enforcement / application metering • [anything]Management Software • Patch management • Software management • Configuration management • Asset management
Case Study(3) • You receive a workstation anti-virus alert • Where do you expect to find log data?
Case Study(4) • Data on someone else’s computer
Gathering Data from People • Interviews • With others • With the suspect • Interview Techniques • Never reveal what you do or do not know Did you ever ask a first grader what happened in school today?
Data Sources – Summary • Defense in depth == forensics in depth • Only you know all the potential data sources • It is always your responsibility to help identify and present the data
The Big Question • Can you ever imagine this event/incident leading to a court case? • Yes: legally sound collection • No: more flexibility but fewer resources; often a good training execrcise • Always consider the costs: • Prosecution • Damage to reputation • Loss of corporate secrets
Case Study(5) • A routine anti-virus alert (revisited)
Preparations • Pre-planning • Training • Consider outsourcing • Managed cost • Impartial results • Add an addendum to your MSSP contract
Decisions, Decisions • CSo, CIO, CEO, CLO • What decisions need to be made? • When and how do you receive elevated authority? • Admin rights • Right to monitor • How do you proceed when there is no decision?
Case Study(6) • What can we learn from: • Email logs • Web server logs • Interviews • Human resources • Who would be involved in making decisions? • What are some possible outcomes?
Law Enforcement • FBI • FTC • US Postal Inspectors • US Secret Service • Local law enforcement • Task forces and other institutions
Law Enforcement • Build relationships beforehand • Cooperation leads to resource sharing • Law Enforcement does not know your network topology
Conclusion • Definition of Forensics • Tell the story: what was lost, how it was lost • Be able to understand process in building legally sound case • Complex issues • Identify forensic capabilities you will need in a typical corporate environment • Only you know your topology