Evidence Acquisition in Digital Forensics
The first and most important step to solving a cyber security problem is knowing what the problem actually is. Beyond just knowing that a breach occurred, you must also determine what vulnerabilities in your system allowed the breach in the first place, how a malicious external party utilized that weakness, what they did during the breach, and what they may have left behind afterwards.
Given the amount of detail and technical knowledge involved, evidence acquisition in digital forensics should not be left to an IT department to handle without help. Instead, enlist a knowledgeable and dedicated cyber security firm to help you identify the root cause of your issue and work to remedy it in a proactive and secure way.
Imaging of Affected Data
The first step to addressing a cyber security breach of any kind is ascertaining the nature of the breach and the data which may have been affected or compromised by it. In the event that a physical hard drive or storage device is the source of a cyber security problem, evidence acquisition typically involves making an exact copy of the drive in question.
Specifically, a cyber security professional could create an exact copy of a computer or hard drive’s volatile memory—also called random access memory, or RAM—through a process known as forensic imaging. A write blocking device usually plays a key role in this process, as it prevents the original drive from being changed while its copy is being constructed. Once the forensic image is created, it is “hashed” to ensure it is perfectly identical to the original drive.
“Live” Acquisitions
Forensic imaging is the standard way of copying a compromised hard drive or computer for analysis, but in modern times a significant amount of data is hosted in the “cloud,” meaning it cannot be imaged through traditional means. In these cases, a cyber security professional may instead perform a “live” acquisition of data by copying key logical structures and all available relevant files instead of copying the system in its entirety. Either way, the final forensic image produced is still hashed to ensure nothing has changed between the original data and the copied version.
Different Methods of Hashing Data
When a cyber security professional talks about “hashing” a forensic image, they are referring to the process of generating a data structure called a bit string through one of a few standardized algorithms. If both the original drive and the forensic image return the exact same hash value, they are confirmed to be identical. If even one bit of data is different, though, the algorithm will produce extremely different results.
Hash functions are essential to evidence acquisition in digital forensics, as they are used to certify that a forensic image is accurate and therefore useful to someone looking to analyze a cyber security breach—or, as the case may be, to ensure that said image is admissible as evidence in court. The algorithms most commonly used for hashing forensic images are Secure Hash Algorithm 1 (SHA-1) and the MD5 message-digest algorithm, but others may be used to relatively similar effect.
How a Cyber Security Firm Could Help Acquire Evidence for Digital Forensics
Although the fact that a data breach occurred may be obvious, it is impossible to effectively respond to one without functional evidence to analyze. Furthermore, acquiring this evidence is not as simple as just digging around in computer code looking for flaws and signs of ingress.
In order to ensure the evidence acquisition of digital forensics goes smoothly, it is best to seek third-party help. Get in touch today to find out how our qualified cyber security experts could help you or your business.