arXiv subjects

Nhien-An Le-Khac

Publications and source records attributed to Nhien-An Le-Khac.

89 records · Page 5Linked to original sources

arXiv2017

Variance-based Clustering Technique for Distributed Data Mining Applications

Nowadays, huge amounts of data are naturally collected in distributed sites due to different facts and moving these data through the network for extracting useful knowledge is almost unfeasible for either technical reasons or policies. Furthermore, classical par- allel algorithms cannot be applied, specially in loosely coupled environments. This requires to develop scalable distributed algorithms able to return the global knowledge by aggregating local results in an effective way. In this paper we propose a distributed algorithm based on independent local clustering processes and a global merging based on minimum variance increases and requires a limited communication overhead. We also introduce the notion of distributed sub-clusters perturbation to improve the global generated distribution. We show that this algorithm improves the quality of clustering compared to classical local centralized ones and is able to find real global data nature or distribution.

cs.DB↗

arXiv2017

MapExif: an image scanning and mapping tool for investigators

Recently, the integration of geographical coordinates into a picture has become more and more popular. Indeed almost all smartphones and many cameras today have a built-in GPS receiver that stores the location information in the Exif header when a picture is taken. Although the automatic embedding of geotags in pictures is often ignored by smart phone users as it can lead to endless discussions about privacy implications, these geotags could be really useful for investigators in analysing criminal activity. Currently, there are many free tools as well as commercial tools available in the market that can help computer forensics investigators to cover a wide range of geographic information related to criminal scenes or activities. However, there are not specific forensic tools available to deal with the geolocation of pictures taken by smart phones or cameras. In this paper, we propose and develop an image scanning and mapping tool for investigators. This tool scans all the files in a given directory and then displays particular photos based on optional filters (date, time, device, localisation) on Google Map. The file scanning process is not based on the file extension but its header. This tool can also show efficiently to users if there is more than one image on the map with the same GPS coordinates, or even if there are images with no GPS coordinates taken by the same device in the same timeline. Moreover, this new tool is portable; investigators can run it on any operating system without any installation. Another useful feature is to be able to work in a read-only environment, so that forensic results will not be modified. We also present and evaluate this tool real world application in this paper.

cs.CR↗

arXiv2016

Forensics Acquisition and Analysis of instant messaging and VoIP applications

The advent of the Internet has significantly transformed the daily activities of millions of people, with one of them being the way people communicate where Instant Messaging (IM) and Voice over IP (VoIP) communications have become prevalent. Although IM applications are ubiquitous communication tools nowadays, it was observed that the relevant research on the topic of evidence collection from IM services was limited. The reason is an IM can serve as a very useful yet very dangerous platform for the victim and the suspect to communicate. Indeed, the increased use of Instant Messengers on smart phones has turned to be the goldmine for mobile and computer forensic experts. Traces and Evidence left by applications can be held on smart phones and retrieving those potential evidences with right forensic technique is strongly required. Recently, most research on IM forensics focus on applications such as WhatsApp, Viber and Skype. However, in the literature, there are very few forensic analysis and comparison related to IM applications such as WhatsApp, Viber and Skype and Tango on both iOS and Android platforms, even though the total users of this application already exceeded 1 billion. Therefore, in this paper we present forensic acquisition and analysis of these four IMs and VoIPs for both iOS and Android platforms. We try to answer on how evidence can be collected when IM communications are used. We also define taxonomy of target artefacts in order to guide and structure the subsequent forensic analysis. Finally, a review of the information that can become available via the IM vendor was conducted. The achieved results of this research provided elaborative answers on the types of artifacts that can be identified by these IM and VoIP applications. We compare moreover the forensics analysis of these popular applications: WhatApp, Skype, Viber and Tango.

cs.CR↗

arXiv2016

Toward a new mobile cloud forensic framework

Smartphones have created a significant impact on the day to day activities of every individual. Now a days a wide range of Smartphone applications are available and it necessitates high computing resources in order to build these applications. Cloud computing offers enormous resources and extends services to resource-constrained mobile devices. Mobile Cloud Computing is emerging as a key technology to utilize virtually unlimited resources over the Internet using Smartphones. Offloading data and computations to improve productivity, enhance performance, save energy, and improve user experience. Social network applications largely utilize Mobile Cloud Computing to reap the benefits. The social network has witnessed unprecedented growth in the recent years, and millions of registered users access it using Smartphones. The mobile cloud social network applications introduce not only convenience but also various issues related to criminal and illegal activities. Despite being primarily used to communicate and socialize with contacts, the multifarious and anonymous nature of social networking websites increases susceptibility to cybercrimes. Taking into account, the advantage of mobile cloud computing and popularity of social network applications, it is essential to establish a forensic framework based on mobile cloud platform that solves the problems of today forensic requirements. In this paper we present a mobile cloud forensic framework that allows the forensic investigator to collect the automated synchronized copies of data on both mobile and cloud servers to prove the evidence of cloud usage. We also show our preliminary results of this study.

cs.CR↗

arXiv2016

The State of the Art Forensic Techniques in Mobile Cloud Environment: A Survey, Challenges and Current Trends

Smartphones have become popular in recent days due to the accessibility of a wide range of applications. These sophisticated applications demand more computing resources in a resource constraint smartphone. Cloud computing is the motivating factor for the progress of these applications. The emerging mobile cloud computing introduces a new architecture to offload smartphone and utilize cloud computing technology to solve resource requirements. The popularity of mobile cloud computing is an opportunity for misuse and unlawful activities. Therefore, it is a challenging platform for digital forensic investigations due to the non-availability of methodologies, tools and techniques. The aim of this work is to analyze the forensic tools and methodologies for crime investigation in a mobile cloud platform as it poses challenges in proving the evidence. The advancement of forensic tools and methodologies are much slower than the current technology development in mobile cloud computing. Thus, forces the available tools, and techniques become increasingly obsolete. Therefore, it opens up the door for the new forensic tools and techniques to cope up with recent developments. Hence, this work presents a detailed survey of forensic methodology and corresponding issues in a mobile device, cloud environment, and mobile cloud applications. It mainly focuses on digital forensic issues related to mobile cloud applications and also analyze the scope, challenges and opportunities. Finally, this work reviewed the forensic procedures of two cloud storage services used for mobile cloud applications such as Dropbox and SkyDrive.

cs.CR↗

arXiv2016

Forensics in Industrial Control System: A Case Study

Industrial Control Systems (ICS) are used worldwide in critical infrastructures. An ICS system can be a single embedded system working stand-alone for controlling a simple process or ICS can also be a very complex Distributed Control System (DCS) connected to Supervisory Control And Data Acquisition (SCADA) system(s) in a nuclear power plant. Although ICS are widely used to-day, there are very little research on the forensic acquisition and analyze ICS artefacts. In this paper we present a case study of forensics in ICS where we de-scribe a method of safeguarding important volatile artefacts from an embedded industrial control system and several other sources

cs.CR↗

arXiv2016

The End of effective Law Enforcement in the Cloud? To encypt, or not to encrypt

With an exponentially increasing usage of cloud services, the need for forensic investigations of virtual space is equally in constantly increasing demand, which includes as a very first approach, the gaining of access to it as well as the data stored. This is an aspect that faces a number of challenges, stemming not only from the technical difficulties and peculiarities, but equally covers the interaction with an emerging line of businesses offering cloud storage and services. Beyond the forensic aspects, it also covers to an ever increasing amount the non-forensic considerations, such as the availability of logs and archives, legal and data protection considerations from a global perspective and the clashes in between, as well as the ever competing interests between law enforcement to seize evidence which is non-physical, and businesses who need to be able to continue to operate and provide their hosted services, even if law enforcement seek to collect evidence. The trend post-Snowden has been unequivocally towards default encryption, and driven by market leaders such as Apple, motivated to a large extent by the perceived demands for privacy of the consumer. The central question to be explored in this paper is to what extent this trend towards default encryption will have a negative impact on law enforcement investigations and possibilities, and will at the end attempt to provide a solution, which takes into account the needs of both law enforcement, but also of the service providers. It is hoped that the recommendations from this paper will be able to have an impact in the ability for law enforcement to continue with their investigations in an efficient manner, whilst also safeguarding the ability for business to thrive and continue to develop and offer new and innovative solutions, which do not put law enforcement at risk.

cs.CR↗

arXiv2016

Control Flow Change in Assembly as a Classifier in Malware Analysis

As currently classical malware detection methods based on signatures fail to detect new malware, they are not always efficient with new obfuscation techniques. Besides, new malware is easily created and old malware can be recoded to produce new one. Therefore, classical Antivirus becomes consistently less effective in dealing with those new threats. Also malware gets hand tailored to bypass network security and Antivirus. But as analysts do not have enough time to dissect suspected malware by hand, automated approaches have been developed. To cope with the mass of new malware, statistical and machine learning methods proved to be a good approach classifying programs, especially when using multiple approaches together to provide a likelihood of software being malicious. In normal approach, some steps have been taken, mostly by analyzing the opcodes or mnemonics of disassembly and their distribution. In this paper, we focus on the control flow change (CFC) itself and finding out if it is significant to detect malware. In the scope of this work, only relative control flow changes are contemplated, as these are easier to extract from the first chosen disassembler library and are within a range of 256 addresses. These features are analyzed as a raw feature, as n-grams of length 2, 4 and 6 and the even more abstract feature of the occurrences of the n-grams is used. Statistical methods were used as well as the Naive-Bayes algorithm to find out if there is significant data in CFC. We also test our approach with real-world datasets.

cs.CR↗

arXiv2016

Toward a new tool to extract the Evidence from a Memory Card of Mobile phones

Today, a mobile phone is not just a phone but it is a computer that you can also use for calling someone. Besides, in criminal investigations the importance of evidence from the mobile phone is increasing as more and more phones are seized at the Digital Forensic Department of the police. Indeed, the amount of memory cards of these mobile phones that need to be investigated separately is also increasing. Possible reasons are that the mobile phone investigation software does not support the specific mobile phone or the specific, for that investigation, artefacts. Sometimes the software investigates just the internal memory of the mobile phone and not the data which is written on the memory card. Fact is also that although the mobile phone was investigated by the dedicated software, the possibility that the associated memory card contains additional important information is evident. The current procedure to get all of the usable information from a memory card of a mobile phone is very time-consuming process and not user friendly. In this paper, we present a new single tool to simplify the investigation of a memory card from a mobile phone. We also test our tool with WhatsApp application installed on the memory card from different mobile phones.

cs.CR↗

arXiv2016

Forensics Acquisition of IMVU: A Case Study

There are many applications available for personal computers and mobile devices that facilitate users in meeting potential partners. There is, however, a risk associated with the level of anonymity on using instant message applications, because there exists the potential for predators to attract and lure vulnerable users. Today Instant Messaging within a Virtual Universe (IMVU) combines custom avatars, chat or instant message (IM), community, content creation, commerce, and anonymity. IMVU is also being exploited by criminals to commit a wide variety of offenses. However, there are very few researches on digital forensic acquisition of IMVU applications. In this paper, we discuss first of all on challenges of IMVU forensics. We present a forensic acquisition of an IMVU 3D application as a case study. We also describe and analyse our experiments with this application.

cs.CR↗

arXiv2016

Android and Wireless data-extraction using Wi-Fi

Today, mobile phones are very popular, fast growing technology. Mobile phones of the present day are more and more like small computers. The so-called "smartphones" contain a wealth of information each. This information has been proven to be very useful in crime investigations, because relevant evidence can be found in data retrieved from mobile phones used by criminals. In traditional methods, the data from mobile phones can be extracted using an USB-cable. However, for some reason this USB-cable connection cannot be made, the data should be extracted in an alternative way. In this paper, we study the possibility of extracting data from mobile devices using a Wi-Fi connection. We describe our approach on mobile devices containing the Android Operating System. Through our experiments, we also give recommendation on which application and protocol can be used best to retrieve data.

cs.CR↗

arXiv2016

An Integrated Classification Model for Financial Data Mining

Nowadays, financial data analysis is becoming increasingly important in the business market. As companies collect more and more data from daily operations, they expect to extract useful knowledge from existing collected data to help make reasonable decisions for new customer requests, e.g. user credit category, churn analysis, real estate analysis, etc. Financial institutes have applied different data mining techniques to enhance their business performance. However, simple ap-proach of these techniques could raise a performance issue. Besides, there are very few general models for both understanding and forecasting different finan-cial fields. We present in this paper a new classification model for analyzing fi-nancial data. We also evaluate this model with different real-world data to show its performance.

cs.AI↗

arXiv2016

A data mining-based solution for detecting suspicious money laundering cases in an investment bank

Today, money laundering poses a serious threat not only to financial institutions but also to the nation. This criminal activity is becoming more and more sophisticated and seems to have moved from the clichy of drug trafficking to financing terrorism and surely not forgetting personal gain. Most international financial institutions have been implementing anti-money laundering solutions to fight investment fraud. However, traditional investigative techniques consume numerous man-hours. Recently, data mining approaches have been developed and are considered as well-suited techniques for detecting money laundering activities. Within the scope of a collaboration project for the purpose of developing a new solution for the anti-money laundering Units in an international investment bank, we proposed a simple and efficient data mining-based solution for anti-money laundering. In this paper, we present this solution developed as a tool and show some preliminary experiment results with real transaction datasets.

cs.DB↗

arXiv2016

Performance Evaluation of a Natural Language Processing approach applied in White Collar crime investigation

In today world we are confronted with increasing amounts of information every day coming from a large variety of sources. People and co-operations are producing data on a large scale, and since the rise of the internet, e-mail and social media the amount of produced data has grown exponentially. From a law enforcement perspective we have to deal with these huge amounts of data when a criminal investigation is launched against an individual or company. Relevant questions need to be answered like who committed the crime, who were involved, what happened and on what time, who were communicating and about what? Not only the amount of available data to investigate has increased enormously, but also the complexity of this data has increased. When these communication patterns need to be combined with for instance a seized financial administration or corporate document shares a complex investigation problem arises. Recently, criminal investigators face a huge challenge when evidence of a crime needs to be found in the Big Data environment where they have to deal with large and complex datasets especially in financial and fraud investigations. To tackle this problem, a financial and fraud investigation unit of a European country has developed a new tool named LES that uses Natural Language Processing (NLP) techniques to help criminal investigators handle large amounts of textual information in a more efficient and faster way. In this paper, we present briefly this tool and we focus on the evaluation its performance in terms of the requirements of forensic investigation: speed, smarter and easier for investigators. In order to evaluate this LES tool, we use different performance metrics. We also show experimental results of our evaluation with large and complex datasets from real-world application.

cs.IR↗

arXiv2016

Clustering Approaches for Financial Data Analysis: a Survey

Nowadays, financial data analysis is becoming increasingly important in the business market. As companies collect more and more data from daily operations, they expect to extract useful knowledge from existing collected data to help make reasonable decisions for new customer requests, e.g. user credit category, confidence of expected return, etc. Banking and financial institutes have applied different data mining techniques to enhance their business performance. Among these techniques, clustering has been considered as a significant method to capture the natural structure of data. However, there are not many studies on clustering approaches for financial data analysis. In this paper, we evaluate different clustering algorithms for analysing different financial datasets varied from time series to transactions. We also discuss the advantages and disadvantages of each method to enhance the understanding of inner structure of financial datasets as well as the capability of each clustering method in this context.

q-fin.GN↗

arXiv2016

Tiered Forensic Methodology Model for Digital Field Triage by Non-Digital Evidence Specialists

Due to budgetary constraints and the high level of training required, digital forensic analysts are in short supply in police forces the world over. This inevitably leads to a prolonged time taken between an investigator sending the digital evidence for analysis and receiving the analytical report back. In an attempt to expedite this procedure, various process models have been created to place the forensic analyst in the field conducting a triage of the digital evidence. By conducting triage in the field, an investigator is able to act upon pertinent information quicker, while waiting on the full report. The work presented as part of this paper focuses on the training of front-line personnel in the field triage process, without the need of a forensic analyst attending the scene. The premise has been successfully implemented within regular/non-digital forensics, i.e., crime scene investigation. In that field, front-line members have been trained in specific tasks to supplement the trained specialists. The concept of front-line members conducting triage of digital evidence in the field is achieved through the development of a new process model providing guidance to these members. To prove the model's viability, an implementation of this new process model is presented and evaluated. The results outlined demonstrate how a tiered response involving digital evidence specialists and non-specialists can better deal with the increasing number of investigations involving digital evidence.

cs.CR↗

arXiv2015

Towards the Forensic Identification and Investigation of Cloud Hosted Servers through Noninvasive Wiretaps

When conducting modern cybercrime investigations, evidence has often to be gathered from computer systems located at cloud-based data centres of hosting providers. In cases where the investigation cannot rely on the cooperation of the hosting provider, or where documentation is not available, investigators can often find the identification of which distinct server among many is of interest difficult and extremely time consuming. To address the problem of identifying these servers, in this paper a new approach to rapidly and reliably identify these cloud hosting computer systems is presented. In the outlined approach, a handheld device composed of an embedded computer combined with a method of undetectable interception of Ethernet based communications is presented. This device is tested and evaluated, and a discussion is provided on its usefulness in identifying of server of interest to an investigation.

cs.DC↗