Issues with spam

This article takes a detailed view of unsolicited, commercial email, better known as “spam”, examining the current state of spam dissemination, how it is distributed by spammers, the impact and problems spam is causing the IT industry, and what methods are being employed both legislative and technological by various segments of government and the IT industry to help control and/or eliminate spam. In analyzing the various legislative and technological means that are being employed to control and/or eliminate spam, the pros and cons of each method and potential societal impacts are discussed.     

基于链接相似度和作弊系数的Spam网页识别算法

Spam网页主要通过链接作弊手段达到提高搜索排名而获利的目的,根据链接作弊的特征,引入链接相似度和作弊系数两个指标来判定网页作弊的可能性。借鉴BadRank算法思想,从Spam网页种子集合通过迭代计算链接相似度和作弊系数,并根据与种子集合的链接指向关系设置权重,将待判定的网页进行度量。最后选取Anti-Trust Rank等算法作对比实验,结果验证了本文算法在准确率和适应性方面优于对比算法。     

No quick fix for spam

Spam can result in corporate losses, the two biggest of which are lost employee productivity and consumed IT resources. It can also result in the introduction of inappropriate content on the network, such as malware or pornography offers. Spam can be as much as 90 percent of incoming corporate e-mail. Three distinct approaches toward spam blocking have emerged in enterprises: software, hardware appliances, and outsourced services. Companies are now beginning to use these in combination.     

Image spam analysis and detection

Image spam is unsolicited bulk email, where the message is embedded in an image. Spammers use such images to evade text-based filters. In this research, we analyze and compare two methods for detecting spam images. First, we consider principal component analysis (PCA), where we determine eigenvectors corresponding to a set of spam images and compute scores by projecting images onto the resulting eigenspace. The second approach focuses on the extraction of a broad set of image features and selection of an optimal subset using support vector machines (SVM). Both of these detection strategies provide high accuracy with low computational complexity. Further, we develop a new spam image dataset that cannot be detected using our PCA or SVM approach. This new dataset should prove valuable for improving image spam detection capabilities.     

Cost-sensitive three-way email spam filtering

Email spam filtering is typically treated as a binary classification problem that can be solved by machine learning algorithms. We argue that a three-way decision approach provides a more meaningful way to users for precautionary handling their incoming emails. Three email folders instead of two are produced in a three-way spam filtering system, a suspected folder is added to allow users make further examinations of suspicious emails, thereby reducing the chances of misclassification. Different from existing ternary email spam filtering systems, we focus on two issues that are less studied, that is, the computation of required thresholds to define the three email categories, and the interpretation of the cost-sensitive characteristics of spam filtering. Instead of supplying the thresholds based on intuitive understandings of the levels of tolerance for errors, we systematically calculate the thresholds based on decision-theoretic rough set model. A loss function is interpreted as the costs of making classification decisions. A decision is made for which the overall cost is minimum. Experimental results show that the new approach reduces the error rate of misclassifying a legitimate email to spam and demonstrates a better performance for the cost-sensitivity aspect.     

Industry sinks teeth into spam

Faced with the prospect of spam reaching such epidemic proportions that it could undermine the efficiency of email and put people off using the Internet, industry representatives and government officials are currently investigating ways in which to effectively combat the problem.     

基于支持向量机的垃圾标签检测模型

为解决Folksonomy存在垃圾标签的问题,提出垃圾标签检测模型。利用向量空间模型表征用户特征,再用支持向量机将Folksonomy用户二分类。通过检测出隐藏在正常用户群体中的垃圾投放人,以此减少垃圾标签数量。实验结果表明,基于支持向量机的垃圾标签检测模型具有更高的分类精度,优于其他检测方法。     

The Death of spam?

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垃圾邮件过滤技术研究综述*

垃圾邮件过滤是一种主动安全防御技术。首先概述了垃圾邮件过滤的发展历史及其基本概念;然后根据不同的标准对垃圾邮件过滤技术进行了分类,并评述了各种垃圾邮件过滤方法和技术;最后展望了垃圾邮件过滤技术及其产品的发展方向。     

The Prudential gets smart with spam

The Prudential, a UK-based financial company, has installed a spam intelligence service from Tumbleweed, which clamps down on the number of emails being blocked accidentally by spam filters.     

Support vector machines for spam categorization

We study the use of support vector machines (SVM) in classifying e-mail as spam or nonspam by comparing it to three other classification algorithms: Ripper, Rocchio, and boosting decision trees. These four algorithms were tested on two different data sets: one data set where the number of features were constrained to the 1000 best features and another data set where the dimensionality was over 7000. SVM performed best when using binary features. For both data sets, boosting trees and SVM had acceptable test performance in terms of accuracy and speed. However, SVM had significantly less training time.     

Leveraging social networks to fight spam

Social networks are useful for judging the trustworthiness of outsiders. An automated antispam tool exploits the properties of social networks to distinguish between unsolicited commercial e-mail - spam - and messages associated with people the user knows.     

图片垃圾邮件过滤技术综述

从图片垃圾邮件的现状着手,通过对图片垃圾邮件的分析,将图片垃圾邮件与文本垃圾邮件之间的不同点进行了对比,并对图片垃圾邮件的特征进行了总结.与此同时,对图片垃圾邮件过滤中常用的一些过滤方法,例如OCR(最优字符识别)以及指纹技术进行了介绍,分析了其优缺点,并结合它们自身的缺点提出了一些建设性看法.最后对最新的反垃圾邮件研究成果作了简略描述,并对垃圾邮件的发展作出了展望.     

Word sense disambiguation for spam filtering

Spam has become a major issue in computer security because it is a channel for threats such as computer viruses, worms, and phishing. More than 86% of received e-mails are spam. Historical approaches to combating these messages, including simple techniques such as sender blacklisting or the use of e-mail signatures, are no longer completely reliable. Many current solutions feature machine-learning algorithms trained using statistical representations of the terms that most commonly appear in such e-mails. However, these methods are merely syntactic and are unable to account for the underlying semantics of terms within messages. In this paper, we explore the use of semantics in spam filtering by introducing a pre-processing step of Word Sense Disambiguation (WSD). Based upon this disambiguated representation, we apply several well-known machine-learning models and show that the proposed method can detect the internal semantics of spam messages.