What is Computer Forensics?
If you manage or administer information systems and networks, you should understand computer forensics. Forensics is the process of using scientific knowledge for collecting, analyzing, and presenting evidence to the courts. (The word forensics means “to bring to the court.” ) Forensics deals primarily with the recovery and analysis of latent evidence. Latent evidence can take many forms, from fingerprints left on a window to DNA evidence recovered from blood stains to the files on a hard drive.

Because computer forensics is a new discipline, there is little standardization and consistency across the courts and industry. As a result, it is not yet recognized as a formal “scientific” discipline. We define 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.

Why is Computer Forensics Important?
Adding the ability to practice sound computer forensics will help you ensure the overall integrity and survivability of your network infrastructure. You can help your organization if you consider computer forensics as a new basic element in what is known as a “defense-in-depth” approach to network and computer security. For instance, understanding the legal and technical aspects of computer forensics will help you capture vital information if your network is compromised and will help you prosecute the case if
the intruder is caught.

What happens if you ignore computer forensics or practice it badly? You risk destroying vital evidence or having forensic evidence ruled inadmissible in a court of law. Also, you or your organization may run afoul of new laws that mandate regulatory compliance and assign liability if certain types of data are not adequately protected. Recent legislation makes it possible to hold organizations liable in civil or criminal court if they fail to protect customer data.

Computer forensics is also important because it can save your organization money. Many managers are allocating a greater portion of their information technology budgets for computer and network security. International Data Corporation (IDC) reported that the market for intrusion-detection and vulnerability-assessment software will reach 1.45 billion dollars in 2006. In increasing numbers, organizations are deploying network security devices such as intrusion detection systems (IDS), firewalls, proxies, and the
like, which all report on the security status of networks.

From a technical standpoint, the main goal of computer forensics is to identify, collect, preserve, and analyze data in a way that preserves the integrity of the evidence collected so it can be used effectively in a legal case.

What are some typical aspects of a computer forensics investigation?
First, those who investigate computers have to understand the kind of potential evidence they are looking for in order to structure their search. Crimes involving a computer can range across the spectrum of criminal activity, from child pornography to theft of personal data to destruction of intellectual property. Second, the investigator must pick the appropriate tools to use. Files may have been deleted, damaged, or encrypted, and the investigator must be familiar with an array of methods and software to prevent further damage in the recovery process.

Two basic types of data are collected in computer forensics. Persistent data is the data that is stored on a local hard drive (or another medium) and is preserved when the computer is turned off. Volatile data is any data that is stored in memory, or exists in transit, that will be lost when the computer loses power or is turned off. Volatile data resides in registries, cache, and random access memory (RAM). Since volatile data is ephemeral, it is essential an investigator knows reliable ways to capture it.

System administrators and security personnel must also have a basic understanding of how routine computer and network administrative tasks can affect both the forensic process (the potential admissibility of evidence at court) and the subsequent ability to recover data that may be critical to the identification and analysis of a security incident.