[Jason Sachowski is a security professional at ScotiaBank. His content is contributed through the auspices of the (ISC)2 Executive Writers Bureau.]
Cyber forensics has become a hot topic in security -- and a critical skill that many enterprises would like to hire. But exactly what skills and experience does a security pro need to become a forensics expert?
The first set of skills is knowledge of IT technology and its relationship to the collection of security data and digital evidence. For example:
• From the boot sequence to process handling and resource allocations, you must understand the many elements of operating systems and how each OS influences the existence of digital evidence.
• Beneath the OS, you must be able to differentiate the underlying file systems -- how and where digital evidence is structured, stored, and accessed.
• Behind these logical components, you must have a solid knowledge of how physical hardware -- or storage media -- determines how digital evidence is stored and distributed
These aspects of forensics are also useful in other security-related pursuits, such as e-discovery or incident response, making them foundational skills that are essential to every cyber forensic professional. Depending on where you practice and the technologies in your environment, you may also need other technical skills and knowledge, such as cryptography or network communications.
One of the keys to cyber forensics is how you analyze and interpret data. If you rely too much on subjective viewpoints based on your own experience, you may overlook evidence. On the other hand, too much reliance on raw data can also lead to wrong or incomplete conclusions. Software tools have made it easy for just about anyone to perform forensic "analysis," but finding data is only one piece of a larger and more complex puzzle.
Analytics is about the ability to extract meaning, sort through masses of data, and find the hidden patterns and unexpected correlations. It's not about knowing everything -- it's about finding what is relevant and getting closer to the right elements with the right people. To do that, you need to maintain a level of objectivity; set aside your personal and professional influences and biases and focus on the data.
Forensics professionals cannot solely rely on technology to solve problems -- they must build analytical skills that are learned and refined by thinking through trial-and-error. For example, a good forensic investigator doesn't rely solely on the data found online -- printouts, handwritten notes, or manuals may also provide important evidence.
Forensics pros also need some understanding of the law. In additional to understanding process and procedures followed by law enforcement or your employer, you must ensure that all digital evidence is handled in a way that will stand up in court. While you don't need to be a lawyer, here are a few critical precautions and requirements you must ensure are upheld throughout every digital investigation:
• Safeguards must be taken to preserve the original data. This requires taking a bit-level image that can be used throughout the analysis process; the original should not be touched.
• Verify that all data remains unaltered in its originally identified state. Use hash algorithms to validate the authenticity of all data.
• Establish and maintain a proper chain of custody throughout the data's life cycle, from identification to destruction. Evidence must be inventoried, labeled, and controlled to ensure it is not altered or contaminated.
When you're working with digital investigations, always keep in mind that evidence -- or even perhaps you -- may end up in court. Just like police officers record events in their notebooks, forensic investigators must maintain documentation for every interaction.
For example, a forensic investigator's logbook should include (at a minimum): the date, time, and analyst's full name for each interaction. It should illustrate page number/sequence and have no whitespace available -- fill that space with a solid line to prevent supplementary comments from being inserted.
Aside from a logbook, there are other important pieces of documentation that are required throughout the investigation life cycle:
• Acquisition (or seizure) forms must be completed -- prior to being removed from a crime scene -– to accurately identify the evidence and when it was seized.
• Exhibit numbers should be assigned using a centralized record book to catalog and inventory evidence as part of the investigation.
• Labels should be appended to all evidence, associating it to the investigation along with its respective exhibit number.
• Chain of custody must be maintained to demonstrate when and where the evidence is handled, stored, and ownership transferred.
The final piece of documentation is the investigative report. As a technical professional, you will be required to translate techniques, methodologies, and findings so they can be communicated and reproduced across business, civil, or criminal court settings. This can be an overwhelming task for a technical individual who -- depending on experience -- has had limited involvement in the business aspects of cyber forensics.
The ability to navigate both technical and business settings is important in cyber forensics. Whether you are looking to further your industry credibility or advance your career, you need to show you can operate outside the purely technical environment. In addition, you must be able to show that you can consistently apply forensics principles to other IT fields, including e-discovery or incident response.
Cyber forensics is one of the fastest-growing and most in-demand areas of specialty in security. However, it isn't easy to establish your credibility in a way that is universally accepted. (ISC)2 is making an effort to certify this expertise with its new Cyber Forensics Professional certification, but the program is still brand new. You may have to establish your own credentials, both legal and professional.
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