Identifying anti-forensics : Attacks on the digital forensic process

Abstract: The area of digital forensics might be old but the idea that criminals or other organisations are actively working to hide their steps is somewhat new. Roughly a year ago, a company announced that they can actively exploit security flaws in a popular digital forensics suite, thus raising questions of validity of evidence submitted to court. It is not known if this exploit is being used in the wild but the mere thought of security issues existing in tools is a serious issue for law enforcement. This paper sets out to clarify the digital forensic process, what tools are used within the digital forensic process and what anti-forensic techniques are available on the market. Using the digital forensic process as a base, this paper produces a model that classifies anti-forensic techniques into realms and shows which realm affects which stage of the digital forensics process. The digital forensic process, anti-forensic techniques and the model was then tested in a Delphi-inspired study where questions regarding the digital forensic process and anti- forensic techniques was asked to digital forensic specialists as well as information security specialists. The goal of the Delphi-study was to reach a consensus regarding the foundations (process and techniques) and their internal relationships (as described in the model). The first part of this paper’s conclusion is that a digital forensic process should contain the following stages: Planning -> Identification -> Acquisition -> Analysis -> Presentation. The paper also concludes that there are several digital forensic tools available for a practitioner, both open and closed source, and that the practitioner uses a mixture of the two. Apart from the process and the tools used, this paper concludes that there are several anti-forensic techniques available on the market and that these could be used by any malicious user that actively want to disrupt the digital forensic process. A second conclusion is that the proposed model connects the stages of the digital forensic process with anti-forensic techniques though the use of realms. The proposed model can be used to develop anti-anti-forensics methods, processes or techniques.