浅析计算机网络安全缺陷与防范

互联网给人们的生活带来方便的同时,网络安全问题也日趋严重。当前威胁网络安全的因素很多,不法分子利用计算机网络的脆弱性,对网络中存在的安全问题进行计算机网络犯罪,严重危害国家和社会。因而,研究计算机网络安全技术具有现实意义。     

Linux病毒分析与防范的探究

日常生活中Windows的病毒已经习惯而且有着诸多的处理办法,但对越来越多的Linux病毒研究和处理办法较少。对本文着重分析了Linux下五种病毒的类型和原理,并对Linux病毒的防范提出了病毒防范并非仅仅是查杀病毒,而是要对Linux平台全面的系统的安全管理,是一个长期的、细致的过程的理念,同时具体给出了Linux病毒防范的五点建议。     

基于可疑行为识别的PE病毒检测方法

针对当前PE病毒难以防范及查杀的现象,对PE病毒关键技术进行分析,提取病毒典型特征的可疑行为,在此基础上提出一种Windows平台下的静态检测方法。该方法在对程序反编译处理的基础上,以指令序列与控制流图的分析为行为识别依据,完成基于可疑行为识别的病毒检测方法的设计。实验结果证明,该检测方法能有效检测混淆变换病毒。     

高速U盘病毒隔离器的设计与实现

U盘的普及使U盘病毒繁衍迅速,针对信息系统安全保护的需要,设计出一种U盘病毒隔离器。该隔离器具有隔离Autorun病毒、防止PC的数据通过U盘泄密、防止PC中的病毒感染U盘的功能。隔离器能够快速捕获到U盘与主机之间所有底层数据,在此基础上,隔离器中的微控制器(MCU)通过分析、审计和过滤流过隔离器中的底层数据来实现上述功能。经实际检测,该设计能够实现上述功能。     

浅析计算机病毒及防范的措施

计算机病毒已经渗透到信息社会的各个领域,给计算机系统带来了巨大的破坏和潜在的威胁。为了确保信息的安全与畅通,因此,研究计算机病毒的防范措施已迫在眉睫。本文从计算机的特点入手,来初步探讨对付计算机病毒的方法和措施。     

基于系统文件补丁方法的Autorun型病毒根治技术

针对近年大量病毒均借助自动播放功能交叉感染和自动激活的客观实际,提出了一种基于系统外壳文件补丁方法的Autorun型病毒根治方案,并且给出了自动部署这种方案的简便方法,同时在此基础上实现了全新部署系统时的针对Autorun型病毒的先天加固。     

基于神经网络集成的Windows病毒检测方法研究

该文针对Win32PE病毒种类多,破坏力强的特点,提出一种基于神经网络集成的病毒检测方法。神经网络集成采用负相关学习方法进行训练,采用n-gram特征字统计方法得到病毒特征字,计算特征字信息条件熵,来选择作为训练样本的特征字。实验结果表明,神经网络集成改善了传统的特征字比对法不能识别新的病毒,容易被病毒制造者克服的缺点,在保证对Win32PE病毒较高的检测率的同时保持了较低的误检率。     

计算机病毒修改Windows操作系统注册表原理解析

修改注册表是Windows操作系统平台下的计算机病毒对系统进行感染和破坏时的常用手段,因此,对其修改注册表的基本原理进行研究,对防治Windows平台下的计算机病毒具有重要意义。该文将Windows平台下的计算机病毒分成宏病毒、脚本病毒、网页病毒和Win32 PE病毒4类,分别就它们对系统注册表实施修改的原理进行了分析,然后给出了利用系统注册表清除计算机病毒的一般方法,并简要列出了对系统注册表本身的几种常用的安全设置,在文章的最后讨论了Windows平台下计算机病毒修改注册表的共同特点。     

Contribution of laser microdissection-based technology to proteomic analysis in hepatocellular carcinoma developing on cirrhosis

Hepatocellular carcinoma (HCC) is a major cause of cancer worldwide. Proteomic studies provide opportunities to uncover targets for the diagnosis and treatment of this disease. However, in HCC developing in a setting of cirrhosis, the detection of proteome alterations may be hampered by the increased cellular heterogeneity of tissue when analysing global liver homogenates. The aim of this study was to evaluate whether the identification of proteome alterations in these HCC cases was improved when the differential protein profile between tumour and non-tumour areas of liver was determined using hepatocytes isolated by laser microdissection (LM). Differential profiles established with LM-hepatocytes and liver section homogenates using 2-DE and MS exhibited noticeable differences: 30% of the protein spots with deregulated expression in tumorous LM-samples did not display any modification in homogenates; conversely 15% of proteins altered in tumorous homogenates were not impaired in LM-hepatocytes. These alterations resulted from the presence in cirrhotic liver of fibrotic stroma which displayed a protein pattern different from that determined in LM-hepatocytes. In conclusion, our data demonstrate the interest of LM in distinguishing between fibrotic and hepatocyte proteome alterations and thus the benefit of LM to proteome studies of HCC developing in a context of cirrhosis.     

Bias in bacteriophage morphological classification by transmission electron microscopy due to breakage or loss of tail structures

Virtually every study that has used transmission electron microscopy (TEM) to estimate viral diversity has acknowledged that loss of phage tails during sample preparation may have biased the results. However, the magnitude of this potential bias has yet to be constrained. To characterize biases in virus morphological diversity due to tail loss, six phage strains representing the order Caudovirales were inoculated into sterile sediments and soils. Phage particles were then extracted using standard methods. Morphologies of extracted phage particles were compared to those of unmanipulated control samples to determine the extent of tail breakage incurred by extraction procedures. Podoviruses exhibited the smallest frequency of tail loss during extraction (1.2-14%), myoviruses were moderately susceptible to tail breakage (15-40%), and siphoviruses were highly susceptible (32-76%). Thus, TEM assessments of viral diversity in soils or sediments by distribution of tail morphologies may be biased toward podoviruses and virions lacking tails, while simultaneously underestimating the abundance of siphoviruses. However, since the majority of viral capsids observed under TEM were intact, estimates of viral diversity based on the distribution of capsid diameters may provide a more reliable basis for morphological comparisons within and across ecosystems.