结合局部优化匹配的Android恶意家族检测算法

近年来,飞速增长的Android恶意代码给移动安全研究带来了沉重的负担。为海量的恶意样本进行准确的家族分类对移动恶意代码的识别与演变过程研究具有极为重要的作用。基于此目的提出了一种新的基于局部结构优化分析的恶意软件家族识别与分类方法。从应用程序的反编译文件中提取函数调用图,采用基于节点相似度的迭代匹配算法来构建恶意家族特征,通过对待检测应用程序函数调用图与恶意家族特征的匹配来进行应用程序的恶意性检测与家族识别。实验结果表明,该方法较三项已有研究和Androguard工具具有更好的性能。     

基于分层API调用的Android恶意代码静态描述方法

针对Android APK的静态描述,目前主要是采用权限、数据以及API调用序列的方法,而忽视了代码本身的层级结构,因此无法有效地通过这些静态特征来揭示应用程序的可能行为和恶意属性.设计并实现了一种基于代码层次结构的系统API调用描述方法,其主要是提取APK文件中API调用在应用包、对象类、类函数层面的信息,并将这些信息以树形结构表示,通过将不同应用程序的描述树进行逐层对比来计算相似度,揭示恶意应用程序由于在类型和族群上的差异所带来的API调用特征上的区别,从而为Android应用程序的特征描述和恶意检测提供新的视角.实验采用真实多样的已知Android恶意程序来验证描述方法的正确性和系统实现的效果,分析了不同层次和检测情况下该方法的利弊以及可能的改进之处.     

基于多类特征的Android应用恶意行为检测系统

目前针对未知的Android恶意应用可以采用数据挖掘算法进行检测,但使用单一数据挖掘算法无法充分发挥Android应用的多类行为特征在恶意代码检测上所起的不同作用.文中首次提出了一种综合考虑Android多类行为特征的三层混合系综算法THEA(Triple Hybrid Ensemble Algorithm)用于检测Android未知恶意应用.首先,采用动静态结合的方法提取可以反映Android应用恶意行为的组件、函数调用以及系统调用类特征;然后,针对上述3类特征设计了三层混合系综算法THEA,该算法通过构建适合3类特征的最优分类器来综合评判Android应用的恶意行为;最后,基于THEA实现了Android应用恶意行为检测工具Androdect,并对现实中的1126个恶意应用和2000个非恶意应用进行检测.实验结果表明,Androdect能够利用Android应用的多类行为特征有效检测Android未知恶意应用.并且与其它相关工作对比,Androdect在检测准确率和执行效率上表现更优.     

Android平台恶意应用程序静态检测方法

本文构建的静态检测系统主要用于检测Android平台未知恶意应用程序.首先,对待检测应用程序进行预处理,从Android Manifest.xml文件中提取权限申请信息作为一类特征属性;如待检测应用程序存在动态共享库,则提取从第三方调用的函数名作为另一类特征属性.对选取的两类特征属性分别选择最优分类算法,最后根据上述的两个最优分类算法对待检测应用程序的分类结果判定待检测应用程序是否为恶意应用程序.实验结果表明:该静态检测系统能够有效地检测出Android未知恶意应用程序,准确率达到95.4%,具有良好的应用前景.     

一种Android应用程序恶意行为的静态检测方法

目前Android应用程序的安全问题得到越来越多的关注. 提出一种检测Android应用程序中恶意行为的静态分析方法, 该方法采用静态数据流分析技术, 并实现了常量分析算法, 通过跟踪应用程序对常量值的使用来检测恶意订购、资费消耗等多种类型的恶意行为. 实验结果表明, 该方法可以有效检测出Android应用程序的恶意行为, 具有较高的实用性.     

基于图像相似性的Android钓鱼恶意应用检测方法

在移动互联网日益兴盛的今天,攻击者已开始通过移动应用的形式来实施网络钓鱼,而现有的网络钓鱼检测方法主要针对网页钓鱼,无法应对这一新的安全威胁。钓鱼恶意应用的一个显著特点是通过构造与目标应用相似的界面来诱骗用户输入敏感信息。基于这种视觉相似性,提出了一种面向Android平台的钓鱼恶意应用检测方法。该方法通过动态技术截取被检测应用的人机交互界面,利用图像哈希感知算法计算其与目标应用界面的图像相似度。如果相似度超过阈值,则识别被检测应用程序为钓鱼恶意应用。实验表明,该方法可以有效检测Android平台上的恶意钓鱼应用程序。     

基于数据流深度学习算法的Android恶意应用检测方法

目前针对未知的Android恶意应用可以采用机器学习算法进行检测,但传统的机器学习算法具有少于三层的计算单元,无法充分挖掘Android应用程序特征深层次的表达。文中首次提出了一种基于深度学习的算法DDBN （Data-flow Deep BeliefNetwork）对Android应用程序数据流特征进行分析,从而检测Android未知恶意应用。首先,使用分析工具FlowDroid和SUSI提取能够反映Android应用恶意行为的静态数据流特征;然后,针对该特征设计了数据流深度学习算法DDBN,该算法通过构建深层的模型结构,并进行逐层特征变换,将数据流在原空间的特征表示变换到新的特征空间,从而使分类更加准确;最后,基于DDBN实现了Android恶意应用检测工具Flowdect,并对现实中的大量安全应用和恶意应用进行检测。实验结果表明,Flowdect能够充分学习Android应用程序的数据流特征,用于检测未知的Android恶意应用。通过与其他基于传统机器学习算法的检测方案对比,DDBN算法具有更优的检测效果。     

基于可解释性的Android恶意软件检测

针对Android恶意软件检测,通常仅有检测结果缺乏对其检测结果的可解释性.基于此,从可解释性的角度分析Android恶意软件检测,综合利用多层感知机和注意力机制提出一种可解释性的Android恶意软件检测方法(multilayer perceptron attention-method, MLP＿At).通过提取Android恶意软件的应用权限和应用程序接口(application programming interface, API)特征来进行数据预处理生成特征信息,采用多层感知机对特征学习.最后,利用BP算法对学习到的数据进行分类识别.在多层感知机中引入注意力机制,以捕获敏感特征,根据敏感特征生成描述来解释应用的核心恶意行为.实验结果表明所提方法能有效检测恶意软件,与SVM、RF、XGBoost相比准确率分别提高了3.65%、3.70%和2.93%,并能准确地揭示软件的恶意行为.此外,该方法还可以解释样本被错误分类的原因.     

基于SVM的Android应用程序安全检测综述

当前基于SVM的Android应用程序安全检测技术主要是通过将SVM算法与动静态分析方法相结合,应用于Android应用程序的漏洞和恶意软件的检测中,而恶意软件的检测又可分为恶意行为的检测和恶意代码的检测。故本文按SVM算法应用到的检测领域分类,分别对其应用于Android应用程序中的恶意行为检测、恶意代码检测和漏洞检测方面的研究进行分析与讨论,并总结了当前该领域中仍然存在的一些问题,给出了SVM算法和其应用于Android安全检测中的改进之处,最后对未来的发展进行了展望。     

融合多特征的Android恶意软件检测方法

针对当前基于机器学习的Android恶意软件检测方法特征构建维度单一,难以全方位表征Android恶意软件行为特点的问题,文章提出一种融合软件行为特征、Android Manifest.xml文件结构特征和Android恶意软件分析经验特征的恶意软件检测方法。该方法提取Android应用的Dalvik操作码N-gram语义信息、系统敏感API、系统Intent、系统Category、敏感权限和相关经验特征,多方位表征Android恶意软件的行为并构建特征向量,采用基于XGBoost的集成学习算法构建分类模型,实现对恶意软件的准确分类。在公开数据集DREBIN和AMD上进行实验,实验结果表明,该方法能够达到高于97%的检测准确率,有效提升了Android恶意软件的检测效果。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.