Have you ever wondered what happens after a cyberattack? How do investigators find out who was responsible, what they did, or how they got in? The answers often come from digital forensics, the science of collecting, preserving, and analyzing evidence from digital devices. This room will introduce you to this fascinating field, explaining how digital clues are gathered from computers, phones, and networks to solve cybercrimes and security incidents.

Digital forensics is a critical skill in modern cybersecurity. Whether you're responding to a data breach, investigating insider threats, or supporting law enforcement, understanding how to handle digital evidence properly is essential. In this room, you'll learn the fundamental principles and processes that make digital investigations reliable and legally sound.

What You Will Learn

• Understand what digital forensics is and why it's important for cybersecurity.
• Learn the standard step-by-step process used in all digital investigations.
• Identify common sources of digital evidence, from hard drives to cloud services.
• Recognize the core principles that ensure evidence is preserved correctly.
• Gain awareness of real-world applications and career paths in digital forensics.

What You Should Know First

• Basic computer and internet knowledge (files, folders, web browsing).
• General understanding of cybersecurity concepts (malware, hacking).
• Familiarity with basic networking ideas (IP addresses, how data travels online).
• A curious mindset and attention to detail!

How to Succeed in This Room

• Read carefully: Concepts build on each other from one task to the next.
• Use the visualizations: The diagrams and charts are designed to make complex ideas clear.
• Think practically: Relate what you learn to real-world scenarios.
• Take your time: This is an introduction - focus on grasping the core ideas, not memorizing every detail.

Optional Video

This optional video covers the fundamental concepts of digital forensics. It's helpful but not required to complete the room.

Digital forensics is the process of identifying, preserving, analyzing, and presenting digital evidence. Think of it as detective work for computers, phones, networks, and any device that stores data. Just as a traditional detective looks for fingerprints and fibers, a digital forensics expert looks for file histories, log files, and network connections.

The main goal is to find out what happened, when it happened, how it happened, and who was responsible. This information is used to solve crimes, support legal cases, investigate security breaches, and recover lost data.

How is it Different from "Real-World" Forensics?

While the thinking process is similar, the evidence is very different. You can't physically hold a deleted email or dust a server for fingerprints. Digital evidence is fragile, easily changed, and often hidden.

Real-World Evidence	Digital Evidence
Fingerprints, DNA, weapons	Files, emails, log data, metadata
Stored in an evidence bag	Stored as bits and bytes on a device
Can be physically examined	Requires special tools to view and interpret
Changes are often visible	Changes can be invisible without analysis

Below is a Visual Demonstration of Real-World Evidence vs. Digital Evidence

Core Principles: Don't Touch the Evidence!

The most important rule in digital forensics is preserving the original evidence. Unlike physical evidence, simply turning on a computer can change crucial data. Experts use special tools and methods to create an exact, read-only copy of the data (called a forensic image) to work from, keeping the original safe.

This leads to two key ideas you'll hear often:

1. Integrity: Ensuring the evidence has not been altered.
2. Chain of Custody: A documented log of everyone who handled the evidence, when, and why.

Why Does This Matter?

Imagine a company finds an employee might be stealing data. If their manager simply opens the employee's laptop to look around, they could accidentally change file dates or delete temporary files. A digital forensics expert would first make a forensic image of the laptop's drive. All investigation is done on that copy, so the original evidence stays perfect for court. Following the right process makes the evidence trustworthy.

A Step-by-Step Investigation Framework

Digital forensics follows a careful, methodical process. This ensures evidence is handled correctly and findings are reliable. While real investigations can be complex, they all generally follow these six key phases.

The Six Phases of Digital Forensics

Phase	Main Goal	Key Activities
Identification	Recognize and define the incident.	Determine the scope: What device is involved? What type of crime or incident occurred?
Preservation	Protect the original evidence.	Isolate the device. Use write blockers. Create a forensic image (exact copy).
Collection	Gather the evidence formally.	Document the scene. Securely transfer the forensic image to an analysis lab.
Examination	Look for relevant data.	Use forensic tools to search, recover files, and extract data from the image.
Analysis	Understand what the data means.	Interpret findings. Answer who, what, when, where, how. Draw conclusions.
Presentation	Share the findings clearly.	Create a report for lawyers, management, or court. Explain the process and conclusions.

Walking Through an Example

Let's see how this process works with a simple scenario: An employee is suspected of sending confidential company files via personal email.

1. Identification: The incident is reported. The target is the employee's work computer.
2. Preservation: The computer is taken offline. A forensic technician connects it via a write blocker (a hardware tool that prevents any changes to the drive) and creates a forensic image. A hash value (like a digital fingerprint) is calculated to prove the copy is identical to the original.
3. Collection: The forensic image is stored on a secure drive. The chain of custody log is started.
4. Examination: Using forensic software, the examiner searches the image for email clients, webmail logs, and file transfer history.
5. Analysis: The examiner finds that a large PDF file was uploaded to a personal webmail service last Tuesday at 3:15 PM. They correlate this with login records showing the employee was active on the computer at that time.
6. Presentation: The examiner writes a report stating the evidence suggests the employee transferred the file, detailing the steps taken to reach this conclusion.

It's Not Always a Straight Line

Investigations can loop back. Analysis might reveal a new device to examine, sending the team back to the Identification phase. The process is a framework to ensure thoroughness, not a rigid checklist.

Digital evidence isn't just on a computer's hard drive. It can be found anywhere data is created, stored, or transmitted. A skilled investigator knows where to look and how different pieces of evidence connect to tell the full story. Evidence generally comes from three main places: devices, networks, and the cloud.

Common Sources of Digital Evidence

Evidence Source	What It Is	Examples of Evidence
Computers & Laptops	The most traditional source.	Documents, emails, browsing history, deleted files, system logs, installed programs.
Mobile Devices	Phones and tablets contain rich personal data.	Call logs, text messages (SMS), location history (GPS), app data, social media activity.
Network Logs	Data about traffic moving through a network.	Firewall logs, server access records, router history, login attempts, connection timestamps.
Cloud Storage	Data stored on internet services.	Emails in Gmail/Outlook, files in Dropbox/OneDrive, photos on social media, chat backups.
Peripheral Devices	Other connected hardware.	USB drive history, printer logs, external hard drives, camera memory cards.

Below is a visual map showing how these different evidence sources connect in a modern environment.

Putting It All Together: A Simple Case

Imagine investigating an account hack at a company. You wouldn't just look at one place:

1. Computer (Device): Check the employee's workstation for malware or keyloggers.
2. Server Logs (Network): Look for the unusual login time and the IP address it came from.
3. Email Server (Cloud/Network): Check for a phishing email that tricked the employee into revealing their password.
4. Authentication Logs (Network): See if the same IP address tried to hack other accounts.

Each source provides a piece of the puzzle. The computer might show how the attack happened, the logs show when and from where, and the email shows the initial trick.

The Changing Landscape

While computer hard drives used to be the main target, today's investigations must also consider network evidence (which can show attack patterns) and cloud evidence (which may be controlled by a third-party company and require legal requests to access). A modern digital forensics expert needs to understand all these sources.

Congratulations! You've completed your introduction to the fundamentals of digital forensics. Let's review the key concepts you've explored that form the foundation of this critical cybersecurity field.

Key Takeaways

• Digital forensics is the structured process of finding, preserving, and analyzing evidence from digital devices to understand events and support investigations.
• The core principle is to never alter the original evidence. This is maintained through forensic imaging and a documented chain of custody.
• Investigations follow a standard process: Identification, Preservation, Collection, Examination, Analysis, and Presentation.
• Evidence can come from many sources, including computers, mobile devices, network logs, and cloud services. A good investigation often pieces together clues from multiple sources.
• The ultimate goal is to produce reliable, factual answers about what happened in a way that can be understood by others, such as a legal team or company management.

What You Should Now Understand

You should now have a clear, high-level picture of what digital forensics is and why it is a vital part of responding to security incidents and solving cybercrimes. You understand that it is a careful, methodical science—not just "hacking backward", and that it requires specific tools and procedures to ensure evidence is trustworthy.

Where to Go From Here

This room covered the what and why of digital forensics. Your next steps could involve rooms that dive into the how:

• Computer Forensics: Deep dive into analyzing hard drives and operating systems.
• Network Forensics: Focus on investigating attacks by analyzing network traffic and logs.
• Mobile Forensics: Explore the specialized techniques for extracting evidence from smartphones and tablets.
• Forensic Tool Fundamentals: Get hands-on with the actual software used by professionals.

You've taken the first step into a fascinating and in-demand area of cybersecurity. Keep asking questions, stay curious about how things work, and remember: every click, every file, and every connection leaves a trace.