Passive forensics in image and video using noise features: A review

Due to present of enormous free image and video editing software on the Internet, tampering of digital images and videos have become very easy. Validating the integrity of images or videos and detecting any attempt of forgery without use of active forensic technique such as Digital Signature or Digital Watermark is a big challenge to researchers. Passive forensic techniques, unlike active techniques, do not need any preembeded information about the image or video. The proposed paper presents a comprehensive review of the recent developments in the field of digital image and video forensic using noise features. The previously existing methods of image and video forensics proved the importance of noises and encourage us for the study and perform extensive research in this field. Moreover, in this paper, forensic task cover mainly source identification and forgery detection in the image and video using noise features. Thus, various source identification and forgery detection methods using noise features are reviewed and compared in this paper for image and video. The overall objective of this paper is to give researchers a broad perspective on various aspects of image and video forensics using noise features. Conclusion part of this paper discusses about the importance of noise features and the challenges encountered by different image and video forensic method using noise features.     

Toward a General Ontology for Digital Forensic Disciplines

Ontologies are widely used in different disciplines as a technique for representing and reasoning about domain knowledge. However, despite the widespread ontology‐related research activities and applications in different disciplines, the development of ontologies and ontology research activities is still wanting in digital forensics. This paper therefore presents the case for establishing an ontology for digital forensic disciplines. Such an ontology would enable better categorization of the digital forensic disciplines, as well as assist in the development of methodologies and specifications that can offer direction in different areas of digital forensics. This includes such areas as professional specialization, certifications, development of digital forensic tools, curricula, and educational materials. In addition, the ontology presented in this paper can be used, for example, to better organize the digital forensic domain knowledge and explicitly describe the discipline's semantics in a common way. Finally, this paper is meant to spark discussions and further research on an internationally agreed ontological distinction of the digital forensic disciplines. Digital forensic disciplines ontology is a novel approach toward organizing the digital forensic domain knowledge and constitutes the main contribution of this paper.     

Distributed filesystem forensics: XtreemFS as a case study

Distributed filesystems provide a cost-effective means of storing high-volume, velocity and variety information in cloud computing, big data and other contemporary systems. These technologies have the potential to be exploited for illegal purposes, which highlights the need for digital forensic investigations. However, there have been few papers published in the area of distributed filesystem forensics. In this paper, we aim to address this gap in knowledge. Using our previously published cloud forensic framework as the underlying basis, we conduct an in-depth forensic experiment on XtreemFS, a Contrail EU-funded project, as a case study for distributed filesystem forensics. We discuss the technical and process issues regarding collection of evidential data from distributed filesystems, particularly when used in cloud computing environments. A number of digital forensic artefacts are also discussed. We then propose a process for the collection of evidential data from distributed filesystems.     

Digital forensics as a service: Game on

The big data era has a high impact on forensic data analysis. Work is done in speeding up the processing of large amounts of data and enriching this processing with new techniques. Doing forensics calls for specific design considerations, since the processed data is incredibly sensitive. In this paper we explore the impact of forensic drivers and major design principles like security, privacy and transparency on the design and implementation of a centralized digital forensics service.     

A study on the forensic mechanisms of VoIP attacks: Analysis and digital evidence

This paper discusses the use of communication technology to commit crimes, including crime facts and crime techniques. The analysis focuses on the security of voice over Internet protocol (VoIP), a prevention method against VoIP call attack and the attention points for setting up an Internet phone. The importance of digital evidence and digital forensics are emphasised. This paper provides the VoIP digital evidence forensics standard operating procedures (DEFSOP) to help police organisations and establishes an experimental platform to simulate phone calls, hacker attacks and forensic data. Finally, this paper provides a general discussion of a digital evidence strategy that includes VoIP for crime investigators who are interested in digital evidence forensics.     

Taxonomy of Challenges for Digital Forensics

Since its inception, over a decade ago, the field of digital forensics has faced numerous challenges. Despite different researchers and digital forensic practitioners having studied and analysed various known digital forensic challenges, as of 2013, there still exists a need for a formal classification of these challenges. This article therefore reviews existing research literature and highlights the various challenges that digital forensics has faced for the last 10 years. In conducting this research study, however, it was difficult for the authors to review all the existing research literature in the digital forensic domain; hence, sampling and randomization techniques were employed to facilitate the review of the gathered literature. Taxonomy of the various challenges is subsequently proposed in this paper based on our review of the literature. The taxonomy classifies the large number of digital forensic challenges into four well‐defined and easily understood categories. The proposed taxonomy can be useful, for example, in future developments of automated digital forensic tools by explicitly describing processes and procedures that focus on addressing specific challenges identified in this paper. However, it should also be noted that the purpose of this paper was not to propose any solutions to the individual challenges that digital forensics face, but to serve as a survey of the state of the art of the research area.     

IoT forensics: Exploiting log records from the DAHUA technology CCTV systems

CCTV surveillance systems are ubiquitous IoT appliances. Their forensic examination has proven critical for investigating crimes. DAHUA Technology is a well-known manufacturer of such products. Despite its global market share, research regarding digital forensics of DAHUA Technology CCTV systems is scarce and currently limited to extracting their video footage, overlooking the potential presence of valuable artifacts within their log records. These pieces of evidence remain unexploited by major commercial forensic software, yet they can hide vital information for an investigation. For instance, these log records document user actions, such as formatting the CCTV system's hard drive or disabling camera recording. This information can assist in attributing nefarious actions to specific users and hence can be invaluable for understanding the sequence of events related to incidents. Therefore, in this paper, several DAHUA Technology CCTV systems are thoroughly analyzed for these unexplored pieces of evidence, and their forensic value is presented.     

Modelling and refinement of forensic data acquisition specifications

This paper defines a model of a special type of digital forensics tools, known as data acquisition tools, using the formal refinement language Event-B. The complexity and criticality of many types of computer and Cyber crime nowadays combined with improper or incorrect use of digital forensic tools calls for more robust and reliable specifications of the functionality of digital forensics applications. As a minimum, the evidence produced by such tools must meet the minimum admissibility standards the legal system requires, in general implying that it must be generated from reliable and robust tools. Despite the fact that some research and effort has been spent on the validation of digital forensics tools by means of testing, the verification of such tools and the formal specification of their expected behaviour remains largely under-researched. The goal of this work is to provide a formal specification against which implementations of data acquisition procedures can be analysed.     

Forensic analysis of WeChat on Android smartphones

WeChat is one of the most popular instant-messaging smartphone applications in the world. At the end of 2015, WeChat had 697 million monthly active users from over 200 countries. Although WeChat was designed originally for communication between relatives and friends, its abundant social functions are now also used by criminals for communication, and even for the organization and coordination of criminal acts. Therefore, communication records of social networking services like WeChat extracted from the smartphones of criminals are always the vital digital evidences for the investigation and prosecution of criminal cases. At present, only a few literatures focused on WeChat forensics. This paper describes several common questions that arise in forensic examinations of Android WeChat and provides corresponding technical methods that are useful to address these questions. This paper is intended to provide vital references for the investigators and researchers working on the digital forensics.     

Reverse engineering of ReFS

File system forensics is an important part of Digital Forensics. Investigators of storage media have traditionally focused on the most commonly used file systems such as NTFS, FAT, ExFAT, Ext2-4, HFS+, APFS, etc. NTFS is the current file system used by Windows for the system volume, but this may change in the future. In this paper we will show the structure of the Resilient File System (ReFS), which has been available since Windows Server 2012 and Windows 8. The main purpose of ReFS is to be used on storage spaces in server systems, but it can also be used in Windows 8 or newer. Although ReFS is not the current standard file system in Windows, while users have the option to create ReFS file systems, digital forensic investigators need to investigate the file systems identified on a seized media. Further, we will focus on remnants of non-allocated metadata structures or attributes. This may allow metadata carving, which means searching for specific attributes that are not allocated. Attributes found can then be used for file recovery. ReFS uses superblocks and checkpoints in addition to a VBR, which is different from other Windows file systems. If the partition is reformatted with another file system, the backup superblocks can be used for partition recovery. Further, it is possible to search for checkpoints in order to recover both metadata and content.Another concept not seen for Windows file systems, is the sharing of blocks. When a file is copied, both the original and the new file will share the same content blocks. If the user changes the copy, new data runs will be created for the modified content, but unchanged blocks remain shared. This may impact file carving, because part of the blocks previously used by a deleted file might still be in use by another file. The large default cluster size, 64 KiB, in ReFS v1.2 is an advantage when carving for deleted files, since most deleted files are less than 64 KiB and therefore only use a single cluster. For ReFS v3.2 this advantage has decreased because the standard cluster size is 4 KiB.Preliminary support for ReFS v1.2 has been available in EnCase 7 and 8, but the implementation has not been documented or peer-reviewed. The same is true for Paragon Software, which recently added ReFS support to their forensic product. Our work documents how ReFS v1.2 and ReFS v3.2 are structured at an abstraction level that allows digital forensic investigation of this new file system. At the time of writing this paper, Paragon Software is the only digital forensic tool that supports ReFS v3.x.It is the most recent version of the ReFS file system that is most relevant for digital forensics, as Windows automatically updates the file system to the latest version on mount. This is why we have included information about ReFS v3.2. However, it is possible to change a registry value to avoid updating. The latest ReFS version observed is 3.4, but the information presented about 3.2 is still valid. In any criminal case, the investigator needs to investigate the file system version found.     

A review of quality procedures in the UK forensic sciences: What can the field of digital forensics learn?

With a reliance on the various forms of forensic science evidence in complex criminal investigations, the measures for ensuring its quality are facing increasing scrutiny. Improvements to quality management systems, to ensure both the robust application of scientific principles and the accurate interpretation and reporting of results, have arisen as a consequence of high-profile rebuttals of forensic science evidence, combined with process improvements driven by evaluation of current practice. These improvements are crucial to ensure validity of results as well as providing assurance for all those involved in the Criminal Justice System. This work first examines the quality management systems utilised for the examination and analysis of fingerprint, body fluid and DNA evidence. It then proceeds to highlight an apparent lack of comparable quality assurance mechanisms within the field of digital forensics, one of the newest branches of forensic science. Proposals are provided for the improvement of quality assurance for the digital forensics arena, drawing on the experiences of, and more well-established practices within, other forensic disciplines.     

A RAM triage methodology for Hadoop HDFS forensics

This paper discusses the challenges of performing a forensic investigation against a multi-node Hadoop cluster and proposes a methodology for examiners to use in such situations. The procedure's aim of minimising disruption to the data centre during the acquisition process is achieved through the use of RAM forensics. This affords initial cluster reconnaissance which in turn facilitates targeted data acquisition on the identified DataNodes. To evaluate the methodology's feasibility, a small Hadoop Distributed File System (HDFS) was configured and forensic artefacts simulated upon it by deleting data originally stored in the cluster. RAM acquisition and analysis was then performed on the NameNode in order to test the validity of the suggested methodology. The results are cautiously positive in establishing that RAM analysis of the NameNode can be used to pinpoint the data blocks affected by the attack, allowing a targeted approach to the acquisition of data from the DataNodes, provided that the physical locations can be determined. A full forensic analysis of the DataNodes was beyond the scope of this project.     

Advanced Framework for Digital Forensic Technologies and Procedures*

Abstract: Recent trends in global networks are leading toward service‐oriented architectures and sensor networks. On one hand of the spectrum, this means deployment of services from numerous providers to form new service composites, and on the other hand this means emergence of Internet of things. Both these kinds belong to a plethora of realms and can be deployed in many ways, which will pose serious problems in cases of abuse. Consequently, both trends increase the need for new approaches to digital forensics that would furnish admissible evidence for litigation. Because technology alone is clearly not sufficient, it has to be adequately supported by appropriate investigative procedures, which have yet become a subject of an international consensus. This paper therefore provides appropriate a holistic framework to foster an internationally agreed upon approach in digital forensics along with necessary improvements. It is based on a top‐down approach, starting with legal, continuing with organizational, and ending with technical issues. More precisely, the paper presents a new architectural technological solution that addresses the core forensic principles at its roots. It deploys so‐called leveled message authentication codes and digital signatures to provide data integrity in a way that significantly eases forensic investigations into attacked systems in their operational state. Further, using a top‐down approach a conceptual framework for forensics readiness is given, which provides levels of abstraction and procedural guides embellished with a process model that allow investigators perform routine investigations, without becoming overwhelmed by low‐level details. As low‐level details should not be left out, the framework is further evaluated to include these details to allow organizations to configure their systems for proactive collection and preservation of potential digital evidence in a structured manner. The main reason behind this approach is to stimulate efforts on an internationally agreed “template legislation,” similarly to model law in the area of electronic commerce, which would enable harmonized national implementations in the area of digital forensics.     

Ideal log setting for database forensics reconstruction

The ability to reconstruct the data stored in a database at an earlier time is an important aspect of database forensics. Past research shows that the log file in a database can be useful for reconstruction. However, in many database systems there are various options that control which information is included in the logs. This paper introduces the notion of the ideal log setting necessary for an effective reconstruction process in database forensics. The paper provides a survey of the default logging preferences in some of the popular database management systems and identifies the information that a database log should contain in order to be useful for reconstruction. The challenges that may be encountered in storing the information as well as ways of overcoming the challenges are discussed. Possible logging preferences that may be considered as the ideal log setting for the popular database systems are also proposed. In addition, the paper relates the identified requirements to the three dimensions of reconstruction in database forensics and points out the additional requirements and/or techniques that may be required in the different dimensions.     

When finding nothing may be evidence of something: Anti-forensics and digital tool marks

There are an abundance of measures available to the standard digital device users which provide the opportunity to act in an anti-forensic manner and conceal any potential digital evidence denoting a criminal act. Whilst there is a lack of empirical evidence which evaluates the scale of this threat to digital forensic investigations leaving the true extent of engagement with such tools unknown, arguably the field should take proactive steps to examine and record the capabilities of these measures. Whilst forensic science has long accepted the concept of toolmark analysis as part of criminal investigations, ‘digital tool marks’ (DTMs) are a notion rarely acknowledged and considered in digital investigations. DTMs are the traces left behind by a tool or process on a suspect system which can help to determine what malicious behaviour has occurred on a device. This article discusses and champions the need for DTM research in digital forensics highlighting the benefits of doing so.     

BrowStExPlus: A Tool to Aggregate IndexedDB Artifacts for Forensic Analysis

As the Internet and World Wide Web have rapidly evolved and revolutionized the applications in everyday life, it is a demanding challenge for investigators to keep up with the emerging technologies for forensic analyses. Investigating web browser usages for criminal activities, also known as web browser forensics, is a significant part of digital forensics as crucial browsing information of the suspect can be discovered. Particularly, in this study, an emerging web storage technology, called IndexedDB, is examined. Characteristics of IndexedDB technology in five major web browsers under three major operating systems are scrutinized. Also, top 15 US websites ranked by Alexa are investigated for their data storage in IndexedDB. User screen names, ids, and records of conversations, permissions, and image locations are some of the data found in IndexedDB. Furthermore, BrowStEx, a proof‐of‐concept tool previously developed, is extended and cultivated into BrowStExPlus, with which aggregating IndexedDB artifacts is demonstrated.     

“I couldn't find it your honour,it mustn't be there!” – Tool errors,tool limitations and user error in digital forensics

The field of digital forensics maintains significant reliance on the software it uses to acquire and investigate forms of digital evidence. Without these tools, analysis of digital devices would often not be possible. Despite such levels of reliance, techniques for validating digital forensic software are sparse and research is limited in both volume and depth. As practitioners pursue the goal of producing robust evidence, they face the onerous task of both ensuring the accuracy of their tools and, their effective use. Whilst tool errors provide one issue, establishing a tool's limitations also provides an investigatory challenge leading the potential for practitioner user-error and ultimately a grey area of accountability. This article debates the problems surrounding digital forensic tool usage, evidential reliability and validation.     

Forensic acquisition and analysis of palm webOS on mobile devices

The emergence of webOS on Palm devices has created new challenges and opportunities for digital investigators. With the purchase of Palm by Hewlett Packard, there are plans to use webOS on an increasing number and variety of computer systems. These devices can store substantial amounts of information relevant to an investigation, including digital photographs, videos, call logs, SMS/MMS messages, e-mail, remnants of Web browsing and much more. Although some files can be obtained from such devices with relative ease, the majority of information of forensic interest is stored in databases on a system partition that many mobile forensic tools do not acquire. This paper provides a methodology for acquiring and examining forensic duplicates of user and system partitions from a device running webOS. The primary sources of digital evidence on these devices are covered with illustrative examples. In addition, the recovery of deleted items from various areas on webOS devices is discussed.     

Cloud forensics–Tool development studies & future outlook

In this work, we describe our experiences in developing cloud forensics tools and use them to support three main points:First, we make the argument that cloud forensics is a qualitatively different problem. In the context of SaaS, it is incompatible with long-established acquisition and analysis techniques, and requires a new approach and forensic toolset. We show that client-side techniques, which are an extension of methods used over the last three decades, have inherent limitations that can only be overcome by working directly with the interfaces provided by cloud service providers.Second, we present our results in building forensic tools in the form of three case studies: kumodd–a tool for cloud drive acquisition, kumodocs–a tool for Google Docs acquisition and analysis, and kumofs–a tool for remote preview and screening of cloud drive data. We show that these tools, which work with the public and private APIs of the respective services, provide new capabilities that cannot be achieved by examining client-side artifacts.Finally, we use current IT trends, and our lessons learned, to outline the emerging new forensic landscape, and the most likely course of tool development over the next five years.