Digital Forensics: The Ultimate Guide
Digital forensics has become a mainstay in the world of cybercrime investigation. While traditional methods have involved manual analysis, advances in artificial intelligence and machine learning are making digital forensics more accessible and efficient.
Digital forensics investigations are becoming more and more common. That's because today’s digital society is littered with bad actors with malicious intent -- so, by leveraging digital forensics, cyber investigators can dig deep into this web of deceit and skullduggery.
This guide is designed to walk you through everything you need to know about digital forensics: from what it is, to how it's performed, to the tools that make it possible.
What is Digital Forensics?
Digital forensics involves preserving, identifying, extracting and documenting evidence from electronic devices. Analysts who practice digital forensics try to identify and collect evidence from cybercrimes or other crimes covered by legislation regarding information technology, such as theft, fraud, espionage and child protection offences.
The process of digital forensics includes accessing seized hardware and using specialized software tools to search for relevant evidence during an investigation. Forensic teams analyze and identify data found on various types of electronic devices, like computers and smart devices.
The History of Digital Forensics
Rooted in the personal computing revolution, the history of digital forensics stretches back to the late 1970s when IBM released its first personal computer. In the 1990s, countries around the world legislated digital forensics as an important tool for law enforcement agencies. (Also read: Advanced Analytics: Police Tools Combating Crime.)
Today, there are five branches of technology in a digital forensics investigation:
- Seizure, forensic imaging and media analysis.
- Examination of relevant artefacts.
- Access control through authentication mechanisms like passwords or tokens.
- Legal consulting, such as document review or litigation management, software tools for incident response or post-incident workflows.
Although digital forensics is associated with the computing revolution, forensics has a long and rich history dating back to the late 1800s. In 1879, Hans Gross was the first to use scientific study in criminal investigations. He was a German jurist who helped establish the field of forensic science.
Other important years in the history of forensics include:
- 1932. The FBI set up a lab that allowed law enforcement officers from across the United States to access their services. This lab played a significant role in developing digital forensics as we know it today.
- 1992. The term “computer forensics” was used for the first time in academic literature. It appeared in an article written by Peter Sommer and Michael Goodman called “Computers and Law: The Use of Computers in British Criminal Investigations.”
- 2000. The first FBI Regional Computer Forensic Laboratory (RCFL) was established. This lab trained law enforcement officers in digital forensics techniques and methodology.
- 2002. The Scientific Working Group on Digital Evidence (SWGDE) published the first book about digital forensics called “Best Practices for Computer Forensics.” This book outlined best practices for computer forensics investigators and examiners.
- 2010. Simson Garfinkel identified issues facing digital investigations. His paper “Digital Evidence: A Forensic Science Perspective” highlighted many of the challenges investigators face when dealing with digital evidence.
Types of Digital Forensics
There are many types of digital forensics, but the most common are:
- Disk (file-carving) forensics.
- Network forensics.
- Wireless forensics.
- Data forensics.
- Malware forensics, which involves examining malware infections such as viruses and rootkits to find out how they got in and if they’ve been eradicated. (Also read: How to Find and Remove Camera Malware.)
- Email forensics.
- Memory forensics, which is used to examine the contents of both Random Access Memory (RAM), which is primary-volatile memory, and Read-Only Memory (ROM), which is primary-non-volatile memory. Memory forensics can be quite tricky and requires expertise and special equipment.
- Mobile forensics.
In all types of digital forensics, investigators are looking for pieces of evidence -- no matter how small -- to build a picture of the facts or to look for clues that might join the dots in a wider case. Alternatively, investigators may use the data to look for certain types of traffic they suspect are malicious -- such as an encapsulated packet that isn’t quite what it appears to be.
There are three main types of digital forensics analysis. They are:
1. Live Analysis
Live analysis is when a forensic tool is used to process data in real time. We typically find these tools in endpoint security products or security information and event management (SIEM) systems. They identify threats as they occur and alert administrators in real time.
2. Forensic Analysis
Forensic analysis involves using a forensic tool to process data after it has been collected. These tools are found in eDiscovery or digital forensics platforms. They analyze data collected from endpoints, disks or network devices.
3. Hybrid Analysis
Hybrid analysis is when a forensic tool is used to process both live and forensic data.
What Do Digital Forensics Investigators Do?
Digital forensics investigators can study a wide range of things, including cybercrime and consumer protection services. The process of digital forensics may also include seizing devices or preserving devices to preserve the evidence left behind after someone has tampered with them, while in use by an offender who has now left the scene.
Collecting the evidence required for digital forensics takes a lot of effort. This includes pinpointing things like what evidence is present, where it is stored and how it is stored.
Digital forensics investigators' basic duties include:
When an incident occurs, the first order of business is to locate and identify evidence and determine the access paths an attacker used to infiltrate the organization. (Also read: Uncovering Security Breaches.)
The next step involves digitizing the evidence and preventing people from tampering with the crime scene or incident.
This means photographing everything -- including hardware, software and documents -- and taking notes on anything that seems relevant. It’s also important to document the time and date of each image taken as well as any identifying information about who took them.
Digital forensics investigators use software to create an exact copy of a piece of digital media and then examine the copy without altering the original.
Documenting digital forensic investigation findings is an essential step in describing the digital evidence found in the investigation. A thorough documentation process should include:
- An analysis of all evidence collected.
- A timeline of events.
- A description of how the evidence was collected.
- A description of the analysis performed.
Once the evidence has been extracted, the forensic team can start sniffing out bad actors. This may involve recovering deleted files or examining a machine's contents remotely.
By creating a detailed documentation plan, investigators can ensure they capture adequate evidence and maintain the chain of custody.
Information should be clear and understandable, and be written in a fashion that participants can easily understand. There’s no room for any ambiguity within any summaries or explanations.
Forensic teams require access to the best techniques and tools to solve complicated cases. In order to do their job effectively, forensic analysts need to be familiar with a wide range of software and hardware tools. They also need to have a strong understanding of how computers work and how data is stored.
Challenges of Digital Forensics
While today's digital forensics teams face a number of challenges, an underlying theme defining many of them is the increasing complexity of advanced threats and the speed of intrusion. There’s also the mind-boggling volume of data and the need to identify and analyze evidence. (Also read: Business Email Compromise (BEC) Attacks Explained: Are You at Risk?)
On top of that, multiple cybersecurity incidents can happen at the same time -- and these have to be managed quickly to arrive at a successful outcome, especially among law enforcement agencies. Organizations' Incident Response (IR) teams need to understand what happened, why it happened and how to fix it.
Digital Forensics Tools
Types of Digital Forensics Tools
Digital forensics tools are divided into seven major categories:
- Disk and data capture tools.
- File viewers.
- Internet analysis tools.
- Email analysis tools.
- Mobile devices analysis tools.
- Network forensics tools.
- Database forensics tools.
The History of Digital Forensics Tools
In today's era of digital forensics, the volume of data and analysis requirements has doubled -- if not tripled -- from a few years ago. Thus, digital forensics can quickly snowball for any organization, especially law enforcement agencies.
That means digital forensics tools need to address two issues:
- The overwhelming amount of data organizations today create and store.
- The momentous legal implications accompanying every step of the digital forensics process, especially preserving the chain of custody.
The Federal Law Enforcement Training Center (FLETC) first recognized the need for software like this in 1989. Its solution, called DIBS, was released commercially in 1991.
After the 1990s, demand for digital evidence led to the development of tools like EnCase and FTK, which allowed analysts to examine copies of media without live forensics. There are now trends towards live memory forensics in tools like WindowsSCOPE. Live memory forensics can be executed on mobile devices with tools like Wireshark and Hashkeeper.
The Future of Digital Forensics Tools
Digital forensics tools have advanced significantly over the past few years. New tools have been developed that analyze both live and forensic data, while legacy tools have been enhanced to allow for new types of analysis.
Some of the latest digital forensics tools include advanced robotics. This integration allows law enforcement to crack smart devices captured during an investigation by tirelessly entering thousands of PIN number combinations.
Many organizations, including law enforcement agencies and corporations, are also turning to artificial intelligence and machine learning to automate the analysis process and reduce the manual data examination process. (Also read: Robotic Process Automation: What You Need to Know.)
The Benefits of Automated Digital Forensics
Automating the collection of forensically sound evidence presentations, from witnesses to investigators and prosecutors, can dramatically reduce the time and expense of digital forensic investigations.
Moreover, once the evidence is collected, automated forensics software can significantly reduce the time and human resources needed to create defensible evidence presentations such as reports and exhibits. (Also read: The Top 6 Ways AI Is Improving Business Productivity.)
With advancements in robotics and automated software developments, digital forensics has evolved from a painstaking process to a more automated and cost-effective one.
In the past, forensic experts had to manually extract data from systems and devices to conduct digital forensic investigations. Now, however, automated software tools make the process easier and quicker, categorizing evidence, scoring, and prioritizing the evidence in seconds with speed and accuracy.
Specialist forensics companies like Cellebrite, Grayshift, and Magnet Forensics have introduced new advances in digital forensics. Basis Technology has reduced the latest toolkits down from the size of an attaché case to a simple USB drive, freeing up valuable time for law enforcement agencies and corporate organizations.