What Is Digital Forensics? Meaning, Importance, and Types

Digital forensics is defined as a forensic science branch that deals with the recovery, investigation, and preservation of digital evidence while upholding legal standards. This article explains digital forensics in detail.

What Is Digital Forensics?
Types of Digital Forensics
Digital Forensics Process
Importance of Digital Forensics

What Is Digital Forensics?

Digital forensics is a forensic science branch that deals with recovering, investigating, and preserving digital evidence while upholding legal standards.

The global forensics industry is expected to generate around $27,705 million by 2028, according to the 2022 forensic technologies market report by Vantage Market Research. This figure makes sense because of the world’s constant, dynamic technological advancements.Â

The computer used to be a lone server in a corporate setting. Now, a computer sits within all aspects of everyday life. Computers are a part of smartwatches, mobile phones, CCTV systems, or even smart sprinkler systems. No industry can progress without embedding digital technology into its processes. The internet of things has enabled various consumer systems to connect to each other.Â

â€˜Computer forensics’ was the first term to be used for the investigation of computer-related crimes. The FBI launched the first computer forensics program in 1984, and the first honeypot trap was created in 1986 by Cliff Stoll at the Lawrence Berkeley National Laboratory. Computer forensics took off as a profession, mainly to curb the spread of child pornography.Â

Subsequently, the term digital forensics began to be used, covering any piece of technology that holds digital data. We use the terms digital forensics, computer forensics, and cyber forensics interchangeably.

Forensics is typically associated with the analysis of any crime scene. After a robbery, for example, the crime scene is combed for fingerprints and anything else that may lead to DNA evidence. With digital forensics, a device becomes the crime scene. The investigator tries to figure out who accessed it, what was stored on it, what could have been deleted, etc.

Two groups of people mainly use digital forensics:

Law enforcement agencies in criminal and civil cases: These agencies use digital evidence to aid suspects’ convictions or acquittals. These cases can vary from murder trials to civil cases such as those involving transfer of property.
Incident response teams in organizations: These teams are the first responders to cyber attacks such as data breaches or ransomware threats. They use digital forensics to investigate the points of entry and possible remediation.

Specific events in corporate settings trigger digital forensic investigations. These events include abnormal activity in the network or servers, corporate espionage, cyberattacks, intellectual property theft, bankruptcy investigations, or industry compliance audits.Â

The end goal of cyber forensics is to conduct a structured investigation informed by guidelines, resulting in a document. This document must be ready for use as proof in a court of law or in audit offices.

A cyber forensics investigator is an expert with a bachelor’s (or higher) degree in computer forensics. This professional must have the knack for understanding criminal intent and follow the investigation thread accordingly.

â€˜Digital evidence’ depends on the device type being scraped through. This can be anything from user account data to electronic door logs. Investigators can gather two types of digital evidence:

Volatile data: Volatile data is digital information stored in a temporary medium. This data is lost when the device is powered off. The most common volatile data in a digital forensics investigation is random access memory (RAM). Other examples are network connections, open files, running processes, and active sessions. Usually, one can gather some residual data from these sources.
Nonvolatile data: Nonvolatile data is digital information stored in permanent mediums, such as hard disks. The data is not lost even when the device is switched off. Nonvolatile data includes system files, event logs, dump files, configuration files, and account information. This data is less tricky to retrieve for evidence purposes than volatile data.

Digital forensics tools can be hardware- or software-based. These tools are used to inspect devices while maintaining the integrity of the data. Some standard tools are:

File analysis tools: These tools extract and analyze individual files.
Network analysis tools: These are predominantly network monitoring tools that extract traffic and payload information.
Database analyzers: These tools extract, analyze, and query the database to gather the necessary information.
Registry tools: Windows-based computing systems maintain user activity in something called registries. These tools gather information from them.
Data capture tools: These tools capture data, both encrypted and otherwise. They provide a window into persistent hard disks and enable data extraction without damaging original content.
Email scanners: They scan all email communications for evidence. These are important for investigating social engineering attacks.
Mobile device scanners: These devices scan internal and mobile memories in mobile devices.Â

The computer forensics process is reactiveâ€“an investigation that kicks off after the occurrence of an event. It is separate from the cybersecurity process that an organization must include for overall security posture. Cybersecurity measures make sure that such events are proactively minimized.

See More: What Is Advanced Persistent Threat? Definition, Lifecycle, Identification, and Management Best Practices

Types of Digital Forensics

Computer forensics started as a single science; however, it has branched off because of the variety of digital data. Based on the focus of the investigation, the different types of digital forensics are:

1. Electronic discovery

Electronic discovery, or e-discovery, is digital data analysis, processing, and preservation. It is used in a regulatory or legal context.

2. Forensic data analysis

This is the type of cyber forensics that deals explicitly with organized data. It involves data analysts combing through troves of data to arrive at usable evidence. It mainly affects the financial fraud space.

3. Incident Response

Incident response is digital forensics from a corporate point of view. This type of forensics aims to ensure business continuity and reduce the impact of an event (such as a data breach). Internal teams in an organization mainly carry it out.

4. Computer forensics

Computer forensics is digital forensics that deals with accessing, gathering, and analyzing information on computer systems that operate at a computing or storage capacity. Most types of digital forensics are a branch of computer forensics.

5. Network forensics

Standalone computers are rare today. Almost all digital devices are connected to each other and the internet using computer networks. Network forensics involves the analysis of network traffic patterns and incriminating payloads.Â

6. Database forensics

Database forensics involves the analysis and extraction of data and metadata from databases. This includes data stored by third-party services in a contract with the suspect. These might even be SaaS vendors when we consider incidents in organizations.

7. Disk forensics

Another subset of computer forensics, disk forensics, specializes in data retrieval and recovery from nonvolatile devices.Â

8. Memory forensics

While disk forensics focuses on persistent storage, memory forensics focuses on RAM. Memory forensics is also called live acquisition since it presents the â€˜crime scene’ as it is.Â

9. Cloud forensics

With most systems on the cloud now, cloud forensics deals with cloud-hosted information. It requires the analysis of configuration, security, and the geolocation of cloud-based assets. Cloud forensics requires cooperation from cloud vendors (such as AWS and Google Cloud).

10. Email forensics

Email forensics involves retrieving and scanning all email communication, including the deleted ones. Forensic analysts look for identities, content, time stamps, and other metadata attached to the emails. Email forensics looks for forged emails and malicious content, such as phishing emails.

11. Malware forensics

Malware forensics is the type of forensics dealing with tracing the source of malware that has already been injected into the system. It is sometimes a part of incident response. Malware forensic analysts investigate the extent of damage and try to trace it back to the code used to build the malware.

Most digital forensic investigators specialize in more than one of these types. The type of digital forensics used in a case depends on the evidence present and the nature of the crime (or incident) that investigators must solve.Â

See More: What Is a Cyber Threat? Definition, Types, Hunting, Best Practices, and Examples

Digital Forensics Process

Digital forensics, no matter what type, requires a preconceived and systematic approach. Several digital forensic process models exist that can be followed. The steps in each of these models vary based on the goal of the investigation: law enforcement, auditing, or incident response.Â

No matter which model is adopted, a few steps are common across all of them, such as:

Step 1: Investigation preparation

This is the first stage of any cyber forensic investigation. Here, investigators ensure they have the right tools and people. This ultimately depends on the type of event that is being investigated.Â

In the case of a legal investigation, the investigation team obtains a search authority. In a criminal case, the search authority comes with a search warrant or a subpoena. In a civil case, it might just be consent to a search.Â

Forensic tools are validated at this stage too. Investigators must clear each piece of hardware and software of issues and have their accuracy verified. This is especially important for new and old tools with new upgrades or patches. Sometimes, one may need a second round of validation before the analysis stage. Every time this validation is done, it needs to be documented.Â

The processes mentioned above are crucial. If done incorrectly, it negates any findings from the investigation and cannot be used in court.Â

In the case of incident response, external investigation teams require an SLA (service-level agreement), while internal teams just need to establish their chain of command. Once this is done, a list of possible digital devices and systems is created. This is done by looking for a digital footprint.

The digital footprint traces an activity. For example, in the case of intellectual property theft, investigators look into the suspect’s behavior on the system. This includes the applications they accessed, which websites they visited, and what devices were used. Tracing the digital footprint produces a list of assets. The items on this list are then seized for in-depth analysis, keeping the criminal intent in mind.

Step 2: Evidence identification

Once the initial details and legalities are determined, the second step is identifying the evidence and finding where it is stored.

During this stage, it is essential to document the evidence, where it is stored, and the format in which it is stored. This could be an email or a video clip that indicates the event being investigated.Â

Step 3: Collection of evidence

The collection stage of digital forensics involves carefully extracting this evidence while ensuring no damage occurs. Sometimes, this step is as straightforward as making a hard disk copy and combing through it.

However, it might not be as simple as it seems in all scenarios. This step can also involve recovering deleted files or cracking passwords to gain access.Â

Data is also examined at this stage and whittled down where necessary. When the haystack is smaller, the needle is easier to find. Once the data becomes accessible, it is isolated and secured. Backups are created, making sure all content and metadata are the same.

Step 4: Evidence preservation

The original data that acts as digital evidence is now isolated and cannot be handled by anyone without authority. Forensic images are exact copies of digital proof, done at the bit level (0 or 1). The process of generating this bitstream image is called imaging.

Hashing is a mathematical algorithm that processes the original bitstream and the images. The hashing function creates a unique value for every unique bitstream it processes. These hashes are treated as the â€˜fingerprints’ of the digital evidence. An image and the original digital evidence are deemed the same if their fingerprints match.

A chain of custody is established and documented during this stage. This chain of custody is crucial, especially if this evidence is to be used in court. It is a detailed account of the digital evidence, from when it was retrieved to when it is presented in court or to an auditing team. Each time evidence changes hands, it is noted next to a description of that piece of evidence at that point in time.

Step 5: Information analysis

All relevant digital data is examined during this stage, and the most relevant parts are analyzed and extracted. This relevant information is converted into a format one can use to present to the stakeholders or the court.

The amount of time spent in this stage depends on the facts of the event. In some cases, it might stretch over a long period. It is essential to keep the circumstances and facts of the investigation in mind here.

During the analysis stage, investigators try to establish a timeline, identify connections, locate illegal content such as child pornography, and determine whether a system has fallen victim to malware or any other form of cyber attack.Â

By the end of this stage, investigators form conclusions. An example would be marking â€˜likely’ to a question such as â€˜Has this USB drive been tampered with?’.

This step may take many iterations to reach a desired point of closure. Each action in this stage is documented in the interest of repeatability. Repeatability is required so that an authorized third party can reach the same conclusions by following the same steps with the same tools on the same piece of evidence. This establishes the authenticity of the investigation.

Step 6: Report presentation

Documentation is a step that runs alongside every stage of the digital forensic process. Once the investigation is completed, a post-investigation document covers all findings. The format of this document must be in line with the requirements of the court or client.

Most forensic tools also auto-generate their reports to be consumed by experts. These are technical and cannot be understood by everyone.

This is where the presentation part comes in. The presentation of these reports varies based on the intended audience. For instance, in a court of law, the presentation must be simple enough for the judge and jury to understand while covering the steps taken to acquire the evidence. The presentation can make or break a case in someone’s favor.

After a cybercrime incident, a more technically detailed report does the trick in a technical setup. This report will be the starting point for remediations and possible changes in infrastructure.

Through all these steps, the digital forensic investigation team ensures that:

No data is lost, modified, or overlooked
All analyzed information is the same as the original data extracted
Documentation of every person, tool, and action is carried out
A chain of custody is established

See More: What Is Cyber Threat Intelligence? Definition, Objectives, Challenges, and Best Practices

Why is Digital Forensics Important?

Regardless of the industry vertical, businesses are rapidly evolving due to technological advancements. While this has led to streamlined processes and increased efficiency, it has also increased the attack surface. An attack surface is the multiple points of entry that leave an organization open to external threats.

In a business setting, digital forensics is crucial to incident response and compliance auditing. Investigators must submit the forensic investigation’s documented findings if the incident has a legal aspect.Â

Regulations such as HIPAA require security and privacy controls within the organization’s systems. In case of data breaches, digital forensic reports can also prove to the regulatory bodies that the organization has met all these requirements.Â

Besides, a thorough forensic investigation also leads to the uncovering of other vulnerabilities. Viruses and malware unrelated to the case and yet harmful to the systems may crop up. Organizations can leverage forensic reports to improve their security hygiene.Â

Digital forensics is also used to recover stolen or lost data. Damage analysis is a part of the process.

In a world where the internet provides a cloak of anonymity, digital forensics helps stop online harassment and fraud. All law enforcement agencies now have a cyber cell to deal with these crimes. It even helps defense departments keep track of unusual military activity.

In 2014, after the Russian annexation of Crimea, Russian troops were accused of operating in parts of Ukraine. Russia vehemently denied this. Meanwhile, a Russian sergeant, Alexander Sotkin, was discovered to have posted his selfies on Instagram. Instagram photos are geotagged, so one can easily glean the location of these photographs. It was discovered that he was an on-duty soldier moving between his military base in Russia and certain parts of Ukraine.Â

This is a basic digital forensic example. As cyber warfare has started picking up worldwide, government bodies are preparing digital forensic teams to be ready for battle.

Digital forensics is vital in civil and criminal courts now that human lives have become inextricably entangled with devices. One example of a criminal case that was resolved using digital forensics is the murder of a 67-year-old woman in San Jose, California. The prime suspect alleged that he had met her before she died. The woman was wearing a Fitbit, a fitness tracker that tracks her heart rate. Data gathered from the Fitbit indicated the exact time of the murder. That, combined with CCTV footage from her house, proved that the prime suspect had lied and was with her during her death, and was duly convicted.

A high-profile criminal arrest aided by cyber forensics was that of a serial killer who named himself â€˜The BTK Killer’. The killer, who had a habit of sending cryptic notes to police officers, made the mistake of sending a note on a Microsoft Word document on a floppy disk. Digital forensic investigators could trace the metadata they had extracted from the disk to the killer’s identity.

See More: Dark Web vs. Deep Web: 5 Key Differences

Takeaway

Digital forensics is a dynamic field changing along with the world’s technological landscape. Cyber-attacks have become more common, all thanks to the easy availability of hacking tools and elements such as the dark web. Cloud setups have led to data storage across multiple geographical locations, leading to jurisdiction struggles. Government bodies and organizations worldwide struggle to streamline digital forensic laws and policies. This means heavy investments will be made in this field, making digital forensics difficult to ignore.

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