What Is Digital Forensics and How Do You Get Into It?

Imagine your computer gets compromised. Someone has accessed your files, run unfamiliar programs, or logged in using an account that doesn't belong to them.

How would you find out what happened?

You could start by examining system logs, checking which programs were executed, and looking for traces of suspicious activity. Every piece of evidence could help you understand how the attacker gained access and what they did afterwards.

That's where digital forensics comes in. Digital forensics is an important part of cyber security because it helps investigators reconstruct events, understand security incidents, and make decisions based on evidence.

If you're interested in solving technical problems and investigating cyber attacks, it's a fascinating field to explore.

This guide explains what digital forensics is, how investigations work, the tools and skills you'll need, and how to start learning through TryHackMe.

What Is Digital Forensics?

Digital forensics is the process of collecting, preserving, examining, and analysing digital evidence to understand what happened on a device, system, or network.

Digital evidence is information stored or recorded by electronic systems that can help establish events or activities.

For example, digital evidence might reveal:

• When someone logged into a computer.
• Which files were created, accessed, or modified.
• Whether a suspicious program executed.
• Which network connections a device made.
• What changes occurred before or after a security incident.

Digital forensics investigators examine this evidence to reconstruct events and explain their findings.

The field is used in cyber security investigations, criminal investigations, fraud cases, and other situations where digital activity needs to be examined.

In cyber security, digital forensics often helps answer questions about compromised systems and attacker behaviour.

What Is the Difference Between Digital Forensics and Incident Response?

Digital forensics and incident response are closely connected, but they have different purposes.

Digital forensics focuses on examining evidence to establish what happened.

Incident response (IR) is the process of managing a security incident, including investigating the threat, limiting its impact, removing attacker access, and restoring affected systems.

Together, they are commonly called Digital Forensics and Incident Response (DFIR).

For example, a forensic investigator might discover that an attacker used stolen credentials to access a server.

The incident response team could use that finding to investigate related accounts, restrict compromised access, and determine whether other systems are affected.

The responsibilities often overlap, particularly in smaller security teams.

What Types of Digital Evidence Do Investigators Examine?

Digital investigations involve examining information left behind by systems, applications, and user activity.

Investigators often call these traces digital artefacts.

A digital artefact is a record or piece of information that may help explain what happened on a system. It could be a log entry, file, registry setting, or information recovered from memory.

Different evidence sources answer different questions.

For beginners, Windows event logs and file system artefacts are useful places to start because they help you understand familiar activities such as logins, downloads, and program execution.

What Is File Metadata?

Metadata is information that describes another piece of data.

For example, a document's metadata may include its creation date, modification date, author field, or the software used to produce it.

Investigators can examine that information to understand a file's history.

However, metadata needs careful interpretation. An author field containing someone's name does not automatically prove that person created the document. The value could have been inherited, changed, or entered by another user.

Digital forensics involves understanding what a record establishes and where additional evidence is needed.

What Is Memory Forensics?

Memory forensics is the examination of information captured from a computer's random-access memory (RAM).

RAM holds data that programs use while the computer is running.

A memory capture can contain information about processes, connections, and other activity present at the time of collection.

This makes memory useful when investigating malware or suspicious activity that may not leave complete traces on disk.

Memory is considered volatile evidence because its contents can change rapidly and are generally lost when a computer is powered off.

How Does a Digital Forensics Investigation Work?

Digital forensics follows a structured process to help investigators collect evidence, examine it carefully, and produce findings that other people can verify.

NIST's Guide to Integrating Forensic Techniques Into Incident Response describes four main phases: collection, examination, analysis, and reporting.

1. Collection: Gather Relevant Evidence

The first step is identifying and acquiring information that could help answer the investigation's questions.

For example, if you're investigating a suspicious Windows login, you might collect authentication logs and relevant activity from the affected host.

Investigators need to understand where the evidence came from and how it was acquired.

In some investigations, they create a forensic image, a bit-for-bit copy of a storage device or relevant data source, for examination.

Other investigations use targeted collection to gather particular logs or artefacts. The method depends on the system, available access, and investigation requirements.

2. Examination: Find Useful Information

Once evidence has been collected, investigators process it to identify relevant information.

That could involve opening log files, extracting file metadata, or examining collected registry data.

Specialist tools can help organise large volumes of evidence and make important artefacts easier to inspect.

For example, a Windows event log may contain thousands of entries. Investigators can filter those records to focus on a relevant account, time period, or event type.

3. Analysis: Understand What Happened

Analysis involves interpreting the evidence and connecting relevant observations.

Suppose an investigator finds an unusual login, followed by suspicious PowerShell execution and a connection to another system.

Those observations might be related, but the investigator needs to examine the evidence before reaching a conclusion.

One useful technique is timeline analysis, which involves arranging relevant events in chronological order to reconstruct activity.

Investigators need to account for different time zones, missing records, and alternative explanations. A good forensic conclusion explains what the evidence supports and which questions remain unresolved.

4. Reporting: Explain the Findings

The final phase involves documenting the investigation. A forensic report should explain the original question, the evidence examined, the methods used, and the findings.

It should also identify limitations and any further investigation required.

In a cyber security incident, the report helps responders understand what happened and which systems or accounts may need attention.

These phases aren't always completed in a strict sequence. New findings may require additional collection or examination as the investigation develops.

Why Is Evidence Preservation Important?

Digital evidence can be altered accidentally during an investigation. Opening a file, running a command, or collecting information from a live system may change some of the data being examined.

Investigators therefore need to preserve evidence appropriately and document how it was handled.

Two important concepts are chain of custody and file hashing.

Chain of Custody

A chain of custody is a record showing who collected, accessed, transferred, or handled evidence and when those activities occurred.

It helps establish the history of the material and supports confidence in how it was managed.

Depending on the investigation, the record may include collection details, storage locations, access history, and transfers between investigators.

File Hashing

A cryptographic hash is a value calculated from a file's contents using a mathematical algorithm.

Investigators can use hashes to check whether a collected file and a working copy contain identical data.

For example, you can calculate a SHA-256 hash for a practice file using PowerShell:

The command returns a hash value for the specified file.

You can calculate the hash again later and compare the results. Matching SHA-256 values provide strong evidence that the file contents have not changed between those checks.

However, a matching hash does not establish who created the file or whether its contents are trustworthy. Those questions require supporting evidence.

When practicing digital forensics, preserve your supplied evidence and use working copies where appropriate.

Example: Investigating Suspicious Activity on a Windows Computer

Let's look at a simple fictional investigation.

An employee downloads a document. Shortly afterwards, the organisation's security monitoring system reports unusual PowerShell activity on the employee's workstation.

The investigator wants to determine whether the downloaded document was involved in the suspicious activity.

Step 1: Examine the Process Activity

Start with the available process records. Identify when PowerShell executed, which account was associated with it, and what command-line information was recorded.

Check the parent process, which is the process responsible for launching another process.

For example, PowerShell starting directly from an Office application may be worth investigating in the context of the reported activity.

That relationship can be useful evidence, although it does not automatically establish malicious intent.

Step 2: Examine the Downloaded File

Next, investigate the document. Look at its location and available metadata, then examine any relevant browser, file system, or execution artefacts.

You want to establish whether the file and PowerShell activity can be connected through the available evidence.

A close timestamp is an investigative lead, but it does not prove that opening the document caused the script to execute.

Step 3: Build a Timeline

Arrange the relevant observations in chronological order.

For example:

Each entry should reference the supporting record.

Step 4: Document Your Findings

Your report should explain what the evidence establishes and whether further investigation is needed.

For example, you might confirm that PowerShell executed under a specific user account shortly after a document was downloaded.

If the evidence doesn't establish a connection between the two, you should explain what additional information could help answer that question.

What Skills and Tools Do You Need to Learn Digital Forensics?

You don't need to learn every forensic tool before beginning.

Start by understanding how operating systems work and how their activity is recorded.

Windows and Linux fundamentals, basic networking, log analysis, and file system knowledge provide a useful foundation.

As you progress, you can introduce tools that support specific investigative tasks.

TryHackMe's Windows Forensics 1 room is a useful introduction to registry forensics. When you're ready to explore memory analysis, the Volatility room introduces another important part of the field.

How to Start Learning Digital Forensics on TryHackMe

A good way to begin is to move from foundational knowledge into small investigations before attempting more complex Windows incidents.

Step 1: Learn the Fundamentals

If you're completely new to cyber security, start with Cyber Security 101. The path introduces operating systems, networking, and foundational security concepts.

Those skills will help you understand the evidence you encounter during forensic investigations.

Step 2: Complete Your First Forensics Lab

Next, try Intro to Digital Forensics. The room introduces evidence handling and gives you practical experience examining document and image metadata.

It's a manageable starting point because you can concentrate on a small number of files and practise drawing conclusions from their properties.

Step 3: Investigate Windows Artefacts

Once you're comfortable with the basic investigation process, move into Windows-specific forensic exercises.

Try Windows Forensics 1 to explore how registry data can provide useful evidence. You'll develop a better understanding of how Windows records configuration and activity.

Step 4: Progress to Incident Response and Forensics

With stronger Windows and investigation fundamentals, explore TryHackMe's Windows Incident Response & Forensics path.

It develops deeper skills in evidence collection, Windows artefact analysis, attacker behaviour, and forensic timelines.

The path also covers more advanced areas, including memory and file system investigation.

Your First Digital Forensics Project: Examine a File's Metadata

One of the easiest ways to practice digital forensics is to complete a small investigation and write down what you discovered.

After working through TryHackMe's Intro to Digital Forensics room, use a permitted practice file to create your own short case study.

Your investigation question could be:

What can the available metadata tell us about this document's creation and history?

What Should Your Report Include?

Use a simple structure:

1. Investigation question: Explain what you're trying to establish.
2. Evidence: Describe the file and where the practice material came from.
3. Method: Record the tool and steps you used to examine it.
4. Findings: Explain the relevant metadata and other observations.
5. Conclusion: Describe what the evidence supports and what remains uncertain.

Include a file hash in your evidence inventory if appropriate.

For example, you might discover an author field, a creation timestamp, and information about the software that saved a document.

Explain what those records mean without treating them as definitive proof of who created or handled the file.

When you've finished, review whether another person could follow your method and understand your conclusions.

Can You Build a Career in Digital Forensics?

Yes. Digital forensics skills are relevant to several cyber security roles, including digital forensics analyst, DFIR analyst, incident response analyst, and security analyst.

The responsibilities vary. Some practitioners specialise in collecting and analysing forensic evidence. Others combine forensic investigation with containment, remediation, and incident coordination.

There is also demand for related investigation skills.

The UK government's Cyber Security Skills in the UK Labour Market 2026 report found that incident response appeared in 18% of core cyber security job postings analysed from 2025.

If you're interested in entering the field, concentrate on developing your investigation skills and documenting practical work you can explain.

Start Investigating Digital Evidence With TryHackMe

Digital forensics gives you a way to understand security incidents through the evidence systems leave behind.

You can begin with something as simple as examining a document's metadata, then progress towards reconstructing more complex Windows intrusions.