What is digital forensics?

Digital forensics is a field of forensic science. It is used to investigate cybercrimes but can also help with criminal and civil investigations. Cybersecurity teams can use digital forensics to identify the cybercriminals behind a malware attack, while law enforcement agencies might use it to analyze data from the devices of a murder suspect.

Digital forensics has broad applications because it treats digital evidence like any other form of evidence. Officials follow specific procedures to collect physical evidence from a crime scene. Similarly, digital forensics investigators adhere to a strict forensics process—known as a chain of custody—to ensure proper handling and protection against tampering.

Digital forensics and computer forensics are often referred to interchangeably. However, digital forensics technically involves gathering evidence from any digital device, whereas computer forensics involves gathering evidence specifically from computing devices, such as computers, tablets, mobile phones and devices with a CPU.

Digital forensics and incident response (DFIR) is an emerging cybersecurity discipline that combines computer forensics and incident response activities to enhance cybersecurity operations. It helps accelerate the remediation of cyberthreats while ensuring that any related digital evidence remains uncompromised.

Digital forensics, or digital forensic science, first surfaced in the early 1980s with the rise of personal computers and gained prominence in the 1990s.

However, it wasn’t until the early 21st century that countries like the United States formalized their digital forensics policies. The shift toward standardization stemmed from rising computer crimes in the 2000s and nationwide law enforcement decentralization.

As crimes involving digital devices increased, more individuals became involved in prosecuting such offenses. To ensure that criminal investigations handled digital evidence in a way that was admissible in court, officials established specific procedures.

Today, digital forensics is becoming more relevant. To understand why, consider the overwhelming amount of digital data available on practically everyone and everything.

As society increasingly depends on computer systems and cloud computing technologies, individuals are conducting more of their lives online. This shift spans a growing number of devices, including mobile phones, tablets, IoT devices, connected devices and more.

The result is an unprecedented amount of data from diverse sources and formats. Investigators can use this digital evidence to analyze and understand a growing range of criminal activities, including cyberattacks, data breaches, and both criminal and civil investigations.

Like all evidence, physical or digital, investigators and law enforcement agencies must collect, handle, analyze and store it correctly. Otherwise, data can be lost, tampered with or rendered inadmissible in court.

Forensics experts are responsible for performing digital forensics investigations, and as demand for the field grows, so do the job opportunities. The Bureau of Labor Statistics estimates computer forensics job openings will increase by 31% through 2029.

The National Institute of Standards and Technology (NIST)  outlines four steps in the digital forensic analysis process. Those steps include:

When digital forensics emerged in the early 1980s, there were few formal digital forensics tools. Most forensics teams relied on live analysis, a notoriously tricky practice that posed a significant risk of tampering.

By the late 1990s, the growing demand for digital evidence led to the development of more sophisticated tools like EnCase and forensic toolkit (FTK). These tools enabled forensic analysts to examine copies of digital media without relying on live forensics.

Today, forensic experts employ a wide range of digital forensics tools. These tools can be hardware or software-based and analyze data sources without tampering with the data. Common examples include file analysis tools, which extract and analyze individual files, and registry tools, which gather information from Windows-based computing systems that catalog user activity in registries.

Certain providers also offer dedicated open source tools for specific forensic purposes—with commercial platforms, like Encase and CAINE, offering comprehensive functions and reporting capabilities. CAINE, specifically, boasts an entire Linux distribution tailored to the needs of forensic teams.

Digital forensics contains discrete branches based on the different sources of forensic data.

Some of the most popular branches of digital forensics include:

• Computer forensics (or cyber forensics): Combining computer science and legal forensics to gather digital evidence from computing devices.

• Mobile device forensics: Investigating and evaluating digital evidence on smartphones, tablets and other mobile devices.

• Database forensics: Examining and analyzing databases and their related metadata to uncover evidence of cybercrimes or data breaches.

• Network forensics: Monitoring and analyzing data found in computer network traffic, including web browsing and communications between devices.

• File system forensics: Examining data found in files and folders stored on endpoint devices like desktops, laptops, mobile phones and servers.

• Memory forensics: Analyzing digital data found in a device's random access memory (RAM).

When computer forensics and incident response—the detection and mitigation of cyberattacks in progress—are conducted independently, they can interfere with each other and negatively impact an organization.

Incident response teams can alter or destroy digital evidence while removing a threat from the network. Forensic investigators can delay threat resolution while they hunt down and capture evidence.

Digital forensics and incident response, or DFIR, integrates computer forensics and incident response into a unified workflow to help information security teams combat cyberthreats more efficiently. At the same time, it ensures the preservation of digital evidence that might otherwise be lost in the urgency of threat mitigation.

• Forensic data collection happening alongside threat mitigation: Incident responders use computer forensic techniques to collect and preserve data while they contain and eradicate the threat. They ensure that the proper chain of custody is followed, preventing valuable evidence from being altered or destroyed.

• Post-incident review including examination of digital evidence: In addition to preserving evidence for legal action, DFIR teams use it to reconstruct cybersecurity incidents from start to finish. This process helps them determine what happened, how it occurred, the extent of the damage and how to prevent similar attacks in the future.
  

DFIR can lead to faster threat mitigation, more robust threat recovery and improved evidence for investigating criminal cases, cybercrimes, insurance claims and other security incidents.