What Is Computer Forensics: Learn to Become a Cyber Forensics Expert

What Is Computer Forensics?

The United States’ Computer Emergency Readiness Team (CERT) defines computer forensics as “the discipline that combines elements of law and computer science to collect and analyze data from computer systems, networks, wireless communications, and storage devices in a way that is admissible as evidence in a court of law.”

Since forensics by itself is defined as scientific tests and techniques used to detect and solve crimes, you can see where the worlds of science, law enforcement, and computers neatly intersect. When we consider the ever-increasing incidences of cybercrime, it’s unsurprising that computer forensics is garnering increased interest and attention.

In simple, real-life terms, computer forensics is the digital version of a long-respected procedure for solving computer-related crimes.

What Does Computer Forensics Do and What Are the Phases of Computer Forensics?

Computer forensics gathers and preserves evidence from devices related to the legal matter at hand. Investigators perform a structured investigation while keeping a documented chain of evidence to ascertain what happened on the device in question and who initiated it.

Computer forensics investigators employ many proprietary software forensic applications and techniques to examine a copy of the targeted system’s storage media, looking for hidden folders and unallocated disk space for instances of damaged, deleted, or encrypted files. If investigators find any evidence on the digital copy, it’s carefully recorded in a document called a "finding report." This information then gets verified with the original data in preparation for possible legal proceedings involving deposition, discovery, or actual litigation.

There are six phases to the typical computer forensics examination:

Readiness

Anyone who’s seen crime dramas in movies and television knows that investigators must exercise care when handling evidence, lest it gets somehow compromised and useless in the criminal investigation. Preparation and readiness are the best ways to avoid this pitfall. Investigators need to be trained, tested, verified on their equipment and software and make sure their tools and applications are sufficient for the task. They also must know the boundaries of the law and how to handle surprises (e.g., investigators found child pornography on a hard drive when looking for insider trading).

Evaluation

Once preparation is over, it’s time to get briefed on the assignment’s details and its objectives. This briefing includes risk assessment, resource allocation, health and safety issues, potential conflicts of interest, and team members' assigning roles. This stage also covers disclosing relevant details, facts, or particulars of the case, especially if the team is investigating a cyber attack.

Collection

There are two forms of data collected by computer forensics. There is persistent data, which is data kept on a local hard drive or other related media. This data remains stored even if the system is powered down. The second data form is volatile data found in transit or a device’s memory but is lost if the system is powered down. This stage, also known as “imaging,” is divided into two phases.

Acquisition

This on-site phase entails collecting evidence and latent data from any computer systems and other organization areas affected by the cyber-attack. Investigators identify and secure infected or pertinent devices and conduct interviews with IT staff members or affected end-users.

Collection

This phase is the “bag and tag” part of the investigation. Storage devices and other bits of relevant physical evidence are collected, labeled, and sealed in tamper-resistant containers for secure transport to the forensics lab. Once at the lab, the evidence gets examined far more closely than it could be done on-site.

Analysis

This phase entails the discovery and extraction of information gathered in the previous stage. The investigators carefully research the collected latent data and other evidence in great detail. This research helps investigators figure out where the attack came from, who did it and how, and how future incidents can be avoided. This phase is the nuts and bolts of the actual investigation, and it relies on many different techniques and tools to complete. However, the analysis must adhere to the following guidelines:

• Every step must be recorded and documented
• The analysis must be accurate
• The analysis must be impartial and unbiased
• The investigation team must justify the use of relevant techniques and tools in the analysis
• The analysts must accomplish the task within the given timeframe and with the allocated resources

Presentation

Once the investigators finish their analysis, it’s time to file a report. The computer forensics team prepares a report detailing their findings and presents it to the affected organization's IT team. The investigators also create a second document for use in court. This second report is usually phrased in the less technical language since many lay people will read the report. The document should also include strategies and recommendations that the IT department should take to prevent similar future incidents.

Review

The computer forensics specialists should review the entire examination, looking for ways to improve performance and efficiency in future investigations. This review includes calling out things done correctly and, if anything, things done incorrectly. This evaluation is also an great time to consider any feedback from the client.

Why Is Computer Forensics Important?

We have already touched on how the online world has infringed upon a growing amount of our personal lives. Since not everyone is a friendly, law-abiding person, it's fair to say that criminal behavior also ends up online more often. Because digital evidence-gathering is handled differently from physical “real-world” evidence, we need a field of study specializing in finding, gathering, and analyzing digital evidence.

Also, by analyzing information linked to cyber-based crimes, digital forensics specialists help cyber security and IT professionals create better defenses for systems and data. Think of it as an example of learning from one’s mistakes.

Digital evidence is also increasingly being used in criminal court cases, including offenses like fraud or possessing child pornography. The best way to collect evidence of people’s activities is to go where they are, and more people are online every day.

So here we see yet another example of how technological advantages and shifting human behavior creates changes in real-world professions and demands that they evolve with the times.

What Is Computer Forensics Used For?

Alright, so we now know why we need computer forensics, but what are its specific uses? Here are some usage examples that demonstrate the value of this discipline:

Data Discovery

Computer forensics professionals help law enforcement uncover important data from seized devices such as laptops or cell phones. This information can help prosecute both digital and “real world” crimes.

Damage Remediation 

Computer forensics analyzes data breaches and network attacks to understand the severity and extent of the incident's damage. By getting a clearer picture of what happened and what was affected, organizations can keep using the unaffected data, rather than just shutting everything down.

Hacker Tracking

Private computer forensics companies help businesses track down hackers, uncovering the sources of the attacks, and aiding in identifying the guilty parties.

Network Security

Computer forensics also helps beef up network security and defend private servers, preventing those hacker attacks in the first place. Forensic tools inspect packet data, help organizations isolate suspicious activities, identify hackers and their methods, and design the best defenses against these threats.

Testing Tools

The National Institute for Standards and Technology devised forensic tools for making copies of pertinent evidence from seized devices. These computer forensic tools serve as trial runs to make sure that data copying happens successfully.

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How Do You Become a Cyber Forensics Expert?

There’s a lot involved in becoming a cyber forensics expert, but luckily there are many resources available to teach the needed skills.

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