46 research outputs found

    Towards Principled Dynamic Analysis on Android

    Get PDF
    The vast amount of information and services accessible through mobile handsets running the Android operating system has led to the tight integration of such devices into our daily routines. However, their capability to capture and operate upon user data provides an unprecedented insight into our private lives that needs to be properly protected, which demands for comprehensive analysis and thorough testing. While dynamic analysis has been applied to these problems in the past, the corresponding literature consists of scattered work that often specializes on sub-problems and keeps on re-inventing the wheel, thus lacking a structured approach. To overcome this unsatisfactory situation, this dissertation introduces two major systems that advance the state-of-the-art of dynamically analyzing the Android platform. First, we introduce a novel, fine-grained and non-intrusive compiler-based instrumentation framework that allows for precise and high-performance modification of Android apps and system components. Second, we present a unifying dynamic analysis platform with a special focus on Android’s middleware in order to overcome the common challenges we identified from related work. Together, these two systems allow for a more principled approach for dynamic analysis on Android that enables comparability and composability of both existing and future work.Die enorme Menge an Informationen und Diensten, die durch mobile Endgeräte mit dem Android Betriebssystem zugänglich gemacht werden, hat zu einer verstärkten Einbindung dieser Geräte in unseren Alltag geführt. Gleichzeitig erlauben die dabei verarbeiteten Benutzerdaten einen beispiellosen Einblick in unser Privatleben. Diese Informationen müssen adäquat geschützt werden, was umfassender Analysen und gründlicher Prüfung bedarf. Dynamische Analysetechniken, die in der Vergangenheit hier bereits angewandt wurden, fokussieren sich oftmals auf Teilprobleme und reimplementieren regelmäßig bereits existierende Komponenten statt einen strukturierten Ansatz zu verfolgen. Zur Überwindung dieser unbefriedigenden Situation stellt diese Dissertation zwei Systeme vor, die den Stand der Technik dynamischer Analyse der Android Plattform erweitern. Zunächst präsentieren wir ein compilerbasiertes, feingranulares und nur geringfügig eingreifendes Instrumentierungsframework für präzises und performantes Modifizieren von Android Apps und Systemkomponenten. Anschließend führen wir eine auf die Android Middleware spezialisierte Plattform zur Vereinheitlichung von dynamischer Analyse ein, um die aus existierenden Arbeiten extrahierten, gemeinsamen Herausforderungen in diesem Gebiet zu überwinden. Zusammen erlauben diese beiden Systeme einen prinzipienorientierten Ansatz zur dynamischen Analyse, welcher den Vergleich und die Zusammenführung existierender und zukünftiger Arbeiten ermöglicht

    ARTist: The Android Runtime Instrumentation and Security Toolkit

    Get PDF
    We present ARTist, a compiler-based application instrumentation solution for Android. ARTist is based on the new ART runtime and the on-device dex2oat compiler of Android, which replaced the interpreter-based managed runtime (DVM) from Android version 5 onwards. Since dex2oat is yet uncharted, our approach required first and foremost a thorough study of the compiler suite's internals and in particular of the new default compiler backend Optimizing. We document the results of this study in this paper to facilitate independent research on this topic and exemplify the viability of ARTist by realizing two use cases. Moreover, given that seminal works like TaintDroid hitherto depend on the now abandoned DVM, we conduct a case study on whether taint tracking can be re-instantiated using a compiler-based instrumentation framework. Overall, our results provide compelling arguments for preferring compiler-based instrumentation over alternative bytecode or binary rewriting approaches.Comment: 13 page

    Boxify: Full-fledged App Sandboxing for Stock Android

    Get PDF
    We present the first concept for full-fledged app sandboxing on stock Android. Our approach is based on application virtualization and process-based privilege separation to securely encapsulate untrusted apps in an isolated environment. In contrast to all related work on stock Android, we eliminate the necessity to modify the code of monitored apps, and thereby overcome existing legal concerns and deployment problems that rewriting-based approaches have been facing. We realize our concept as a regular Android app called Boxify that can be deployed without firmware modifications or root privileges. A systematic evaluation of Boxify demonstrates its capability to enforce established security policies without incurring a significant runtime performance overhead

    Hemodynamic and genetic analysis in children with idiopathic, heritable, and congenital heart disease associated pulmonary arterial hypertension

    Get PDF
    Background: Aim of this prospective study was to compare clinical and genetic findings in children with idiopathic or heritable pulmonary arterial hypertension (I/HPAH) with children affected with congenital heart defects associated PAH (CHD-APAH). Methods: Prospectively included were 40 consecutive children with invasively diagnosed I/HPAH or CHD-APAH and 117 relatives. Assessment of family members, pedigree analysis and systematic screening for mutations in TGFß genes were performed. Results: Five mutations in the bone morphogenetic protein type II receptor (BMPR2) gene, 2 Activin A receptor type II-like kinase-1 (ACVRL1) mutations and one Endoglin (ENG) mutation were found in the 29 I/HPAH children. Two mutations in BMPR2 and one mutation in ACVRL1 and ENG, respectively, are described for the first time. In the 11 children with CHD-APAH one BMPR2 gene mutation and one Endoglin gene mutation were found. Clinical assessment of relatives revealed familial aggregation of the disease in 6 children with PAH (HPAH) and one CHD-APAH patient. Patients with mutations had a significantly lower PVR. Conclusion: Mutations in different TGFß genes occurred in 8/29 (27.6%) I/HPAH patients and in 2/11 (18.2%) CHD-APAH patients and may influence the clinical status of the disease. Therefore, genetic analysis in children with PAH, especially in those with I/HPAH, may be of clinical relevance and shows the complexity of the genetic background

    A multicenter international prospective study of the validity and reliability of a COVID-19-specific health-related quality of life questionnaire

    Get PDF
    Purpose: To develop and validate a health-related quality of life (HRQoL) questionnaire for patients with current or previous coronavirus disease (COVID-19) in an international setting. Methods: This multicenter international methodology study followed standardized guidelines for a four-phase questionnaire development. Here, we report on the pretesting and validation of our international questionnaire. Adults with current or previous COVID-19, in institutions or at home were eligible. In the pretesting, 54 participants completed the questionnaire followed by interviews to identify administration problems and evaluate content validity. Thereafter, 371 participants completed the revised questionnaire and a debriefing form to allow preliminary psychometric analysis. Validity and reliability were assessed (correlation-based methods, Cronbach’s α, and intra-class correlation coefficient). Results: Eleven countries within and outside Europe enrolled patients. From the pretesting, 71 of the 80 original items fulfilled the criteria for item-retention. Most participants (80%) completed the revised 71-item questionnaire within 15 min, on paper (n = 175) or digitally (n = 196). The final questionnaire included 61 items that fulfilled criteria for item retention or were important to subgroups. Item-scale correlations were > 0.7 for all but nine items. Internal consistency (range 0.68–0.92) and test–retest results (all but one scale > 0.7) were acceptable. The instrument consists of 15 multi-item scales and six single items. Conclusion: The Oslo COVID-19 QLQ-W61© is an international, stand-alone, multidimensional HRQoL questionnaire that can assess the symptoms, functioning, and overall quality of life in COVID-19 patients. It is available for use in research and clinical practice. Further psychometric validation in larger patient samples will be performed.publishedVersio

    Is post-polyploidization diploidization the key to the evolutionary success of angiosperms?

    Get PDF
    Advances in recent years have revolutionized our understanding of both the context and occurrence of polyploidy in plants. Molecular phylogenetics has vastly improved our understanding of plant relationships, enabling us to better understand trait and character evolution, including chromosome number changes. This, in turn, has allowed us to appreciate better the frequent occurrence and extent of polyploidy throughout the history of angiosperms, despite the occurrence of low chromosome numbers in some groups, such as in Arabidopsis (A. thaliana was the first plant genome to be sequenced and assembled). In tandem with an enhanced appreciation of phylogenetic relationships, the accumulation of genomic data has led to the conclusion that all angiosperms are palaeopolyploids, together with better estimates of the frequency and type of polyploidy in different angiosperm lineages. The focus therefore becomes when a lineage last underwent polyploidization, rather than simply whether a plant is ‘diploid’ or ‘polyploid’. This legacy of past polyploidization in plants is masked by large-scale genome reorganization involving repetitive DNA loss, chromosome rearrangements (including fusions and fissions) and complex patterns of gene loss, a set of processes that are collectively termed ‘diploidization’. We argue here that it is the diploidization process that is responsible for the ‘lag phase’ between polyploidization events and lineage diversification. If so, diploidization is important in determining chromosome structure and gene content, and has therefore made a significant contribution to the evolutionary success of flowering plants

    Executive summary. Expert consensus statement on the diagnosis and treatment of paediatric pulmonary hypertension. The European Paediatric Pulmonary Vascular Disease Network, endorsed by ISHLT and DGPK

    Get PDF
    The European Paediatric Pulmonary Vascular Disease (PVD) Network is a registered, non-profit organisation that strives to define and develop effective, innovative diagnostic methods and treatment options in all forms of paediatric pulmonary hypertensive vascular disease, including specific forms such as pulmonary arterial hypertension (PAH)-congenital heart disease, pulmonary hypertension (PH) associated with bronchopulmonary dysplasia, persistent PH of the newborn, and related cardiac dysfunction. Methods The writing group members conducted searches of the PubMed/MEDLINE bibliographic database (1990-2015) and held five face-to-face meetings with votings. Clinical trials, guidelines, and reviews limited to paediatric data were searched using the terms 'pulmonary hypertension' and 5-10 other keywords, as outlined in the other nine articles of this special issue. Class of recommendation (COR) and level of evidence (LOE) were assigned based on European Society of Cardiology/American Heart Association definitions and on paediatric data only, or on adult studies that included >10% children. Results A total of 9 original consensus articles with graded recommendations (COR/LOE) were developed, and are summarised here. The topics included diagnosis/monitoring, genetics/biomarker, cardiac catheterisation, echocardiography, cardiac magnetic resonance/chest CT, associated forms of PH, intensive care unit/ventricular assist device/lung transplantation, and treatment of paediatric PAH. Conclusions The multipaper expert consensus statement of the European Paediatric PVD Network provides a specific, comprehensive, detailed but practical framework for the optimal clinical care of children with PH
    corecore