Forensic Taxonomy of Android Social Apps

An Android social app taxonomy incorporating artifacts that are of forensic interest will enable users and forensic investigators to identify the personally identifiable information (PII) stored by the apps. In this study, 30 popular Android social apps were examined. Artifacts of forensic interest (e.g., contacts lists, chronology of messages, and timestamp of an added contact) were recovered. In addition, images were located, and Facebook token strings used to tie account identities and gain access to information entered into Facebook by a user were identified. Based on the findings, a two‐dimensional taxonomy of the forensic artifacts of the social apps is proposed. A comparative summary of existing forensic taxonomies of different categories of Android apps, designed to facilitate timely collection and analysis of evidentiary materials from Android devices, is presented.     

An Evidence‐based Forensic Taxonomy of Windows Phone Dating Apps

Advances in technologies including development of smartphone features have contributed to the growth of mobile applications, including dating apps. However, online dating services can be misused. To support law enforcement investigations, a forensic taxonomy that provides a systematic classification of forensic artifacts from Windows Phone 8 (WP8) dating apps is presented in this study. The taxonomy has three categories, namely: Apps Categories, Artifacts Categories, and Data Partition Categories. This taxonomy is built based on the findings from a case study of 28 mobile dating apps, using mobile forensic tools. The dating app taxonomy can be used to inform future studies of dating and related apps, such as those from Android and iOS platforms.     

An Evidence‐Based Forensic Taxonomy of Windows Phone Communication Apps

Communication apps can be an important source of evidence in a forensic investigation (e.g., in the investigation of a drug trafficking or terrorism case where the communications apps were used by the accused persons during the transactions or planning activities). This study presents the first evidence‐based forensic taxonomy of Windows Phone communication apps, using an existing two‐dimensional Android forensic taxonomy as a baseline. Specifically, 30 Windows Phone communication apps, including Instant Messaging (IM) and Voice over IP (VoIP) apps, are examined. Artifacts extracted using physical acquisition are analyzed, and seven digital evidence objects of forensic interest are identified, namely: Call Log, Chats, Contacts, Locations, Installed Applications, SMSs and User Accounts. Findings from this study would help to facilitate timely and effective forensic investigations involving Windows Phone communication apps.     

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.     

We are meeting on Microsoft Teams: Forensic analysis in Windows,Android, and iOS operating systems

Microsoft released a new communication platform, Microsoft Teams, in 2017. Due in part to COVID-19, the popularity of communication platforms, like Microsoft Teams, increased exponentially. Given its user base and increased popularity, it seems likely that digital forensic investigators will encounter cases where Microsoft Teams is a relevant component. However, because Microsoft Teams is a relatively new application, there is limited forensic research on the application particularly focusing on mobile operating systems. To address this gap, an analysis of data stored at rest by Microsoft Teams was conducted on the Windows 10 operating system as well as on Android and Apple iOS mobile operating systems. Basic functionalities, such as messaging, sharing files, participating in video conferences, and other functionalities that Teams provides, were performed in an isolated testing environment. Cellebrite UFED Physical Analyzer and Magnet AXIOM Examine tools were used to analyze the mobile devices and the Windows device, respectively. Manual or non-automated investigation recovered, at least partially, the majority of artifacts across all three operating systems. In this study, a total of 77.6% of the populated artifacts were partially or fully recovered in the manual investigation. On the other hand, forensic tools used did not automatically recover many of the artifacts found with the manual investigation. Only 13.8% of artifacts were partially or fully recovered by the forensic tools across all three devices. These discovered artifacts and the results of the investigations are presented in order to aid digital forensic investigations.     

Forensic Investigation of Cooperative Storage Cloud Service: Symform as a Case Study

Researchers envisioned Storage as a Service (StaaS) as an effective solution to the distributed management of digital data. Cooperative storage cloud forensic is relatively new and is an under‐explored area of research. Using Symform as a case study, we seek to determine the data remnants from the use of cooperative cloud storage services. In particular, we consider both mobile devices and personal computers running various popular operating systems, namely Windows 8.1, Mac OS X Mavericks 10.9.5, Ubuntu 14.04.1 LTS, iOS 7.1.2, and Android KitKat 4.4.4. Potential artefacts recovered during the research include data relating to the installation and uninstallation of the cloud applications, log‐in to and log‐out from Symform account using the client application, file synchronization as well as their time stamp information. This research contributes to an in‐depth understanding of the types of terrestrial artifacts that are likely to remain after the use of cooperative storage cloud on client devices.     

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.     

Forensic analysis of Telegram Messenger on Android smartphones

In this paper we present a methodology for the forensic analysis of the artifacts generated on Android smartphones by Telegram Messenger, the official client for the Telegram instant messaging platform, which provides various forms of secure individual and group communication, by means of which both textual and non-textual messages can be exchanged among users, as well as voice calls.Our methodology is based on the design of a set of experiments suitable to elicit the generation of artifacts and their retention on the device storage, and on the use of virtualized smartphones to ensure the generality of the results and the full repeatability of the experiments, so that our findings can be reproduced and validated by a third-party.In this paper we show that, by using the proposed methodology, we are able (a) to identify all the artifacts generated by Telegram Messenger, (b) to decode and interpret each one of them, and (c) to correlate them in order to infer various types of information that cannot be obtained by considering each one of them in isolation.As a result, in this paper we show how to reconstruct the list of contacts, the chronology and contents of the messages that have been exchanged by users, as well as the contents of files that have been sent or received. Furthermore, we show how to determine significant properties of the various chats, groups, and channels in which the user has been involved (e.g., the identifier of the creator, the date of creation, the date of joining, etc.). Finally, we show how to reconstruct the log of the voice calls made or received by the user.Although in this paper we focus on Telegram Messenger, our methodology can be applied to the forensic analysis of any application running on the Android platform.     

The use of COVID-19 contact tracing app data as evidence of a crime

This commentary draws attention to the introduction of data collected by COVID-19 tracing apps as evidence in criminal proceedings and the novel considerations this evidence presents for criminal justice agents and digital forensics professionals.     

Windows Surface RT tablet forensics

Small scale digital device forensics is particularly critical as a result of the mobility of these devices, leading to closer proximity to crimes as they occur when compared to computers. The Windows Surface tablet is one such device, combining tablet mobility with familiar Microsoft Windows productivity tools. This research considers the acquisition and forensic analysis of the Windows Surface RT tablet. We discuss the artifacts of both the Windows RT operating system and third-party applications. The contribution of this research is to provide a road map for the digital forensic examination of Windows Surface RT tablets.     

Toward a general collection methodology for Android devices

The Android platform has been deployed across a wide range of devices, predominately mobile phones, bringing unprecedented common software features to a diverse set of devices independent of carrier and manufacturer. Modern digital forensics processes differentiate collection and analysis, with collection ideally only occurring once and the subsequent analysis relying upon proper collection. After exploring special device boot modes and Android’s partitioning schema we detail the composition of an Android bootable image and discuss the creation of such an image designed for forensic collection. The major contribution of this paper is a general process for data collection of Android devices and related results of experiments carried out on several specific devices.     

A forensic examination of four popular cross‐platform file‐sharing apps with Wi‐Fi P2P

File‐sharing apps with Wi‐Fi hotspot or Wi‐Fi Direct functions become more popular. They can work on multiple platforms and allow users to transfer files in a concealed manner. However, when criminals use these apps in illegal activities, it becomes an important issue for investigators to find digital evidence on multiple platforms. At present, there are few studies on this topic, and most of them are limited to the single platform problem. In this paper, we propose a forensic examination method for four popular cross‐platform file‐sharing apps with Wi‐Fi hotspot and Wi‐Fi Direct functions: Zapya, SHAREit, Xender, and Feem. We use 22 static and live forensic tools for 11 platforms to acquire, analyze, and classify the forensic artifacts. In our experiments, we find many useful forensic artifacts and classify them into six categories. The experimental results can support law enforcement investigations of digital evidence and provide information for future studies on other cross‐platform file‐sharing apps.     

Android屏幕锁解锁在取证上的应用

移动通信的发展带动了智能终端的普及,随之带来的还有更多的手机犯罪、然而在犯罪手机上取证时往往受到了手机屏幕锁的阻碍。本文研究分析了目前具有最大智能终端市场的Android平台上的屏幕解锁技术：先简单阐述了Android平台的系统架构;然后针对Android智能终端上不同的屏幕锁定方式分别进行研究分析,总结对应加密流程和明文密码规则来简化解锁步骤,提高解密效率;使取证能在更短的时间内完成工作;最后,提出了更多的解锁方式,使取证遇到屏幕锁定时能进行灵活的选择     

Windows 7 Antiforensics: A Review and a Novel Approach

In this paper, we review literature on antiforensics published between 2010 and 2016 and reveal the surprising lack of up‐to‐date research on this topic. This research aims to contribute to this knowledge gap by investigating different antiforensic techniques for devices running Windows 7, one of the most popular operating systems. An approach which allows for removal or obfuscation of most forensic evidence is then presented. Using the Trojan software DarkComet RAT as a case study, we demonstrate the utility of our approach and that a Trojan Horse infection may be a legitimate possibility, even if there is no evidence of an infection on a seized computer's hard drive. Up‐to‐date information regarding how forensic artifacts can be compromised will allow relevant stakeholders to make informed decisions when deciding the outcome of legal cases involving digital evidence.     

Automated identification of installed malicious Android applications

Increasingly, Android smartphones are becoming more pervasive within the government and industry, despite the limited ways to detect malicious applications installed to these phones' operating systems. Although enterprise security mechanisms are being developed for use on Android devices, these methods cannot detect previously unknown malicious applications. As more sensitive enterprise information becomes available and accessible on these smartphones, the risk of data loss inherently increases. A malicious application's actions could potentially leave sensitive data exposed with little recourse. Without an effective corporate monitoring solution in place for these mobile devices, organizations will continue to lack the ability to determine when a compromise has occurred. This paper presents research that applies traditional digital forensic techniques to remotely monitor and audit Android smartphones. The smartphone sends changed file system data to a remote server, allowing for expensive forensic processing and the offline application of traditional tools and techniques rarely applied to the mobile environment. The research aims at ascertaining new ways of identifying malicious Android applications and ultimately attempts to improve the state of enterprise smartphone monitoring. An on-phone client, server, database, and analysis framework was developed and tested using real mobile malware. The results are promising that the developed detection techniques identify changes to important system partitions; recognize file system changes, including file deletions; and find persistence and triggering mechanisms in newly installed applications. It is believed that these detection techniques should be performed by enterprises to identify malicious applications affecting their phone infrastructure.     

微生物物证检验

面对21世纪生物犯罪或生物恐怖活动的新挑战,物证鉴定的新专业--微生物物证检验将成为执法部门侦查和起诉生物犯罪必不可少的手段。微生物物证检验以用作犯罪武器的各种微生物为检验对象,获得微生物种类和能够提供来源信息的菌毒株细致分型结果,达到提供犯罪侦查线索和法庭证据的目的。本文综述了微生物物证检验的定义、特征、技术应用以及美国近年来在微生物物证检验的实践和值得借鉴的成功经验。并建议我国物证鉴定实验室应积极开展研究,建立能够满足生物犯罪侦查需求的微生物物证检验能力。     

A comparison of forensic evidence recovery techniques for a windows mobile smart phone

Acquisition, decoding and presentation of information from mobile devices is complex and challenging. Device memory is usually integrated into the device, making isolation prior to recovery difficult. In addition, manufacturers have adopted a variety of file systems and formats complicating decoding and presentation.A variety of tools and methods have been developed (both commercially and in the open source community) to assist mobile forensics investigators. However, it is unclear to what extent these tools can present a complete view of the information held on a mobile device, or the extent the results produced by different tools are consistent.This paper investigates what information held on a Windows Mobile smart phone can be recovered using several different approaches to acquisition and decoding. The paper demonstrates that no one technique recovers all information of potential forensic interest from a Windows Mobile device; and that in some cases the information recovered is conflicting.     

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.     

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.     

BrowStEx: A tool to aggregate browser storage artifacts for forensic analysis

Web storage or browser storage, a new client-side data storage feature, was recommended as a part of the HTML5 specifications and now widely adopted by major web browser vendors. Web storage with native browser support has changed the paradigm of web application development unprecedentedly because persistent data storage with increased data size can be realized on the client. Web storage is poised to quickly become an area of particular interest for forensic investigators due to the potential to discover critical information from web browser artifacts at client side. However, the literature work on web browser forensics has traditionally focused on browsing history, browser cache, and cookie files (Oh et al., 2011). Therefore, we first discuss the prevalence of web storage implementation in widely used websites. Then, we compare and contrast the web storage technology currently implemented in the five major web browsers, Google Chrome, Internet Explorer, Mozilla Firefox, Opera, and Apple's Safari. Moreover, in order to provide more insights into web storage and enable unified forensic analysis, a proof-of-concept tool, named as BrowStEx (Browser Storage Extractor), is described with implementation details. The commonalities, differences, and the proof-of-concept tool discussed in this paper can be useful in developing advanced forensic tools that can extract browser storage artifacts.