5.

1 Introduction to Cyber Forensics

Definition:
Cyber Forensics (also called Computer Forensics or Digital
Forensics) is the science of identifying, collecting, analyzing,
and preserving digital evidence from electronic devices
such as computers, mobile phones, hard drives, and
networks in a way that is legally admissible in a court of law.
Purpose:
•To investigate cybercrimes (hacking, identity theft,
fraud, cyber terrorism).
•To recover deleted, encrypted, or damaged digital data.
•To establish evidence for legal proceedings.
•To trace cybercriminals and prevent future attacks.
Scope:
Covers crimes involving computers, networks, emails,
mobile phones, IoT devices, and cloud storage.
Used by law enforcement agencies, corporate
investigators, and cybersecurity experts.

Process (Simplified Steps):

•Identification – Recognizing potential sources of digital
evidence.
•Collection – Proper seizure and imaging of data.
•Preservation – Maintaining integrity of evidence (hash
values, chain of custody).
•Analysis – Examining files, logs, metadata, etc.
•Presentation – Submitting reports and findings in a legally
valid format.
5.2 Historical Background of Cyber Forensics
1960s–1970s:
•Early computers were limited to government and research use.
•Digital crime was rare, mostly misuse of mainframes.
1980s:
•Growth of personal computers led to computer fraud, software
piracy, and data theft.
•The FBI and other agencies started using basic forensic techniques.
•First cases of hacking and virus attacks appeared.
1990s:
•Internet boom increased crimes like email scams, hacking, and
online fraud.
•Law enforcement recognized the need for formal digital forensics
methods.
•Organizations like the International Association of Computer
Investigative Specialists (IACIS) were formed.
•Tools such as EnCase and FTK (Forensic Toolkit) were developed.
2000s:
•Rise of cyber terrorism, identity theft, and large-scale hacking
incidents.
•Cyber Forensics became a recognized discipline taught in
universities.
•Governments introduced cybercrime laws (e.g., IT Act 2000 in
India, USA’s Patriot Act).
2010s–Present:
•Expansion to cloud computing, mobile forensics, social media
forensics, IoT forensics, and cryptocurrency investigations.
•Advanced tools (AI, machine learning) are now used to analyze
huge volumes of data.
•Digital forensics has become crucial in both criminal
investigations and corporate compliance.
Example :
Suppose a bank suspects an employee of leaking
customer data. A Cyber Forensic expert would:
•Clone the employee’s computer hard drive.
•Analyze email history, deleted files, USB logs.
•Collect evidence following chain-of-custody rules.
•Present findings in court showing proof of data theft.
5.3 Types of Cyber Forensics
Cyber Forensics is not limited to computers alone. With the growth
of digital devices and the internet, it now covers multiple specialized
branches.
1. Computer Forensics
Focus: Recovery and analysis of data from personal computers,
laptops, and storage media.
Examples of Evidence: Deleted files, system logs, browsing history,
USB usage.
Use Case: Investigating data theft by an employee using a company
PC.
2. Network Forensics
Focus: Monitoring, capturing, and analyzing network traffic to detect
suspicious activities.
Examples of Evidence: Packet captures, intrusion logs, IP addresses,
unauthorized access attempts.
Use Case: Tracing a hacker who attacked a company server.
3. Mobile Device Forensics
Focus: Extracting and analyzing data from smartphones, tablets, and
SIM cards.
Examples of Evidence: Call logs, SMS, WhatsApp chats, GPS data,
photos, app usage.
Use Case: Solving crimes by tracking the suspect’s phone location
history.
4. Database Forensics
Focus: Examining structured data stored in databases.
Examples of Evidence: Transaction logs, deleted records, unauthorized
queries.
Use Case: Detecting manipulation in a company’s financial database.
5. Email Forensics
Focus: Investigating emails to detect fraud, spam, or identity theft.
Examples of Evidence: Header information, IP address of sender,
attachments, timestamps.
Use Case: Tracking phishing scams or fake job offers.
6. Malware Forensics
Focus: Analyzing malicious software such as viruses, worms, Trojans,
ransomware.
Examples of Evidence: Code behavior, payload, attack vectors.
Use Case: Identifying the source and method of a ransomware attack.
7. Cloud Forensics
Focus: Collecting and analyzing data stored in cloud services (Google
Drive, Dropbox, AWS, Azure).
Challenges: Data stored across multiple jurisdictions, encryption, third-
party control.
Use Case: Investigating unauthorized data sharing through cloud
storage.
8. Web & Social Media Forensics
Focus: Examining online content such as websites, forums, and social
media posts.
Examples of Evidence: Fake profiles, messages, shared photos,
cyberbullying posts.
Use Case: Tracking online harassment or fake news spread.
9. IoT (Internet of Things) Forensics
Focus: Analyzing data from IoT devices like smart TVs, wearables, smart
homes, and connected cars.
Examples of Evidence: Logs from smart cameras, fitness tracker data,
vehicle GPS history.
Use Case: Using a fitness tracker to prove suspect’s movement at a
crime scene.
10. Cryptocurrency Forensics (Emerging)
Focus: Tracking financial transactions involving digital currencies
(Bitcoin, Ethereum).
Examples of Evidence: Blockchain transactions, wallet addresses,
exchange records.
Use Case: Tracing money laundering through Bitcoin.
5.3 Digital Forensics Science
Definition:
Digital Forensics Science is the systematic study of
scientific methods and techniques used to identify,
collect, analyze, and preserve digital evidence. It ensures
that the evidence is reliable, authentic, and admissible in
court.
Nature of the Science:
•Interdisciplinary – Combines computer science, law,
criminology, and cybersecurity.
•Evidence-based – Uses logical, repeatable, and
verifiable procedures.
•Technology-driven – Relies on specialized forensic
tools (e.g., EnCase, FTK, Autopsy, Sleuth Kit).
Applications in Digital Forensics Science:
Cybercrime investigation (hacking, fraud, harassment).
Corporate compliance audits.
Civil disputes (IP theft, employee misconduct).
Counter-terrorism and national security.

Example:
If investigators recover a deleted WhatsApp message, they
must scientifically prove:
How it was recovered,
That it hasn’t been tampered with,
And that it can be reliably verified by another expert.
5.4 The Need for Computer Forensics
With the rise of technology, computer forensics has become essential
for law enforcement, business organizations, and individuals.
1. Growth of Cybercrime
Hacking, phishing, identity theft, ransomware, and online scams are
increasing daily.
Forensics helps in detecting criminals and preventing further damage.
2. Legal Requirements
Courts demand authentic and verifiable digital evidence.
Computer Forensics ensures data presented is legally admissible.
3. Data Recovery
Important in cases where files are deleted, encrypted, or damaged.
Helps recover financial records, contracts, or confidential information.
4. Corporate Investigations
Used to investigate employee fraud, policy violations, intellectual
property theft.
Protects organizations from insider threats.
5. National Security
Helps track cyberterrorism, espionage, and attacks on critical
infrastructure.
Essential for defense and intelligence agencies.
6. Digital Age Dependency
Individuals, businesses, and governments store sensitive data
digitally.
Without forensics, cybercrimes would remain undetected and
unpunished.

Example:
Imagine an online banking fraud case where ₹5 lakhs are stolen:
Computer Forensics experts recover the hacker’s IP, trace login
history, and analyze malware used.
This evidence is then presented in court to convict the criminal.
5.5 Cyber Forensics and Digital Evidence
Cyber Forensics & Digital Evidence Link:
Cyber Forensics revolves around finding, preserving, and analyzing
digital evidence that can be presented in a court of law.
Digital Evidence (Definition):
Any information stored, transmitted, or received in digital form that
can prove or disprove a crime.
Types of Digital Evidence:
•Computer Data – Documents, spreadsheets, system logs.
•Network Data – IP addresses, traffic logs, intrusion records.
•Mobile Data – SMS, call records, WhatsApp chats, photos.
•Cloud Data – Stored files, backups, shared links.
•Multimedia Evidence – Images, audio, video recordings.
Key Properties of Digital Evidence:
•Volatile (can be easily lost or altered).
•Easily Replicated (copies must be verified with hash values).
•Admissibility depends on proper collection & preservation.
Example: In a cyberstalking case, digital evidence could include
threatening emails, call logs, and IP addresses from which abusive
messages were sent.
5.6 Forensics Analysis of Email
Why Email Forensics?
Emails are commonly used for phishing, fraud, cyberbullying, identity
theft, and corporate espionage.
Steps in Email Forensics:
•Header Analysis – Examining “Received From” IP, timestamps, and
routing paths.
•Content Analysis – Checking subject lines, body text, links, and
attachments.
•Attachment Analysis – Scanning files for malware, hidden scripts, or
trojans.
•Tracing IP Addresses – Identifying sender’s location.
•Metadata Extraction – File creation time, last modification, hidden
data.
Example: A company receives a phishing email
pretending to be from a bank. Forensic analysis of the
email header reveals the real sender’s IP address,
proving it originated from another country.
5.7 Digital Forensics Lifecycle
The investigation process in digital forensics follows a systematic
lifecycle to ensure evidence integrity.
Phases of Digital Forensics Lifecycle:
•Identification – Recognize potential digital evidence (devices, logs,
emails).
•Preservation – Secure and isolate the evidence (write blockers,
hash values, chain of custody).
•Collection – Acquire data legally and properly (disk imaging,
memory dump).
•Examination – Filter, recover, and organize data (search keywords,
deleted files).
•Analysis – Interpret evidence, correlate logs, reconstruct events.
•Presentation – Prepare reports and testify in court with clear,
simple explanation.
•Review – Evaluate methods used, improve tools & procedures.
Example: If a laptop is seized in a fraud case:
Evidence is identified & preserved,
Hard disk is imaged (collected),
Deleted invoices are examined & analyzed,
Findings are presented in court.
5.8 Challenges in Computer Forensics
Despite its importance, digital forensics faces many challenges:
Large Volume of Data
Modern devices hold terabytes of data → makes analysis time-
consuming.
Data Encryption
Criminals use strong encryption tools to hide information.
Anti-Forensic Techniques
Use of wiping tools, steganography, or anonymizers to cover tracks.
Cloud & Jurisdiction Issues
Data stored in multiple countries → legal complexities.
Volatility of Evidence
RAM data, live chats, and temporary files disappear quickly if not
preserved.
Evolving Technology
Constant updates in IoT, blockchain, AI-driven attacks require
continuous tool upgrades.
Admissibility in Court
Evidence may be challenged if chain of custody is broken.
Shortage of Skilled Experts
Few professionals have expertise in both technical and legal
domains.
Example: In a ransomware attack, even if forensic experts trace the
malware, encrypted files may remain inaccessible without the
decryption key.