Voice over Internet Protocol (VoIP) applications (apps) provide convenient and low cost means for users to communicate and share information with each other in real-time. Day by day, the popularity of such apps is increasing, and people produce and share a huge amount of data, including their personal and sensitive information. This might lead to several privacy issues, such as revealing user contacts, private messages or personal photos. Therefore, having an up-to-date forensic understanding of these apps is necessary. This chapter presents analysis of forensically valuable remnants of three popular Mobile VoIP (mVoIP) apps on Google Play store, namely: Viber, Skype, and WhatsApp Messenger, in order to figure out to what extent these apps reveal forensically valuable information about the users activities. We performed a thorough investigative study of these three mVoIP apps on smartphone devices. Our experimental results show that several artefacts, such as messages, contact details, phone numbers, images, and video files, are recoverable from the smartphone device that is equipped with these mVoIP apps.
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. Abstract Forensic examination of Windows Mobile devices and devices running its successor Windows Phone 7 remains relevant for the digital forensic community. In these devices, the file pim.vol is a Microsoft Embedded Database (EDB) volume that contains information related to contacts, appointments, call history, speed-dial settings and tasks. Current literature shows that analysis of the pim.vol file is less than optimal. We succeeded in reverse-engineering significant parts of the EDB volume format and this article presents our current understanding of the format. In addition we provide a mapping from internal column identifiers to human readable application-level property names for the pim.vol database. We implemented a parser and compared our results to the traditional approach using an emulator and the API provided by the Windows CE operating system. We were able to recover additional databases, additional properties per record and unallocated records. Instant messaging (IM) has changed the way people communicate with each other. However, the interactive and instant nature of these applications (apps) made them an attractive choice for malicious cyber activities such as phishing. The forensic examination of IM apps for modern Windows 8.1 (or later) has been largely unexplored, as the platform is relatively new. In this paper, we seek to determine the data remnants from the use of two popular Windows Store application software for instant messaging, namely Facebook and Skype on a Windows 8.1 client machine. This research contributes to an in-depth understanding of the types of terrestrial artefacts that are likely to remain after the use of instant messaging services and application software on a contemporary Windows operating system. Potential artefacts detected during the research include data relating to the installation or uninstallation of the instant messaging application software, log-in and log-off information, contact lists, conversations, and transferred files. Windows Mobile devices are becoming more widely used and can be a valuable source of evidence in a variety of investigations. These portable devices can contain details about an individual's communications, contacts, calendar, online activities, and whereabouts at specific times. Although forensic analysts can apply their knowledge of other Microsoft operating systems to Windows Mobile devices, there are sufficient differences that require specialized knowledge and tools to locate and interpret digital evidence on these systems. This paper provides an overview of Windows Mobile Forensics, describing various methods of acquiring and examining data on Windows Mobile devices. The locations and data formats of useful information on these systems are described, including text messages, multimedia, e-mail, Web browsing artifacts, and Registry entries. This paper concludes with an illustrative scenario involving MobileSpy monitoring software.