Link spamming intends to mislead search engines and trigger an artificially high link-based ranking of specific target web pages. This paper introduces the concept of spam mass, a measure of the impact of link spamming on a page’s ranking. We discuss how to estimate spam mass and how the estimates can help identifying pages that benefit significantly from link spamming. In our experiments on the host-level Yahoo! web graph we use spam mass estimates to successfully identify tens of thousands of instances of heavy-weight link spamming. 1.

Peer-to-peer (P2P) networks have received great attention for sharing and searching information in large user communities. The open and anonymous nature of P2P networks is one of its main strengths, but it also opens doors to manipulation of the information and of the quality ratings. In our previous work (J. X. Parreira, D. Donato, S. Michel and G. Weikum in VLDB 2006) we presented the JXP algorithm for distributed computing PageRank scores for information units (Web pages, sites, peers, social groups, etc.) within a link- or endorsement-based graph structure. The algorithm builds on local authority computations and bilateral peer meetings with exchanges of small data structures that are relevant for gradually learning about global properties and eventually converging towards global authority rankings. In the current paper we address the important issue of cheating peers that attempt to distort the global authority values, by providing manipulated data during the peer meetings. Our approach to this problem enhances JXP with statistical techniques for detecting suspicious behavior. Our method, coined TrustJXP, is again completely decentralized, and we demonstrate its viability and robustness in experiments with real Web data.

Abstract. The Web is both an excellent medium for sharing information as well as an attractive platform for delivering products and services. This platform is, to some extent, mediated by search engines in order to meet the needs of users seeking information. Search engines are the “dragons” that keep a valuable treasure: information [13]. Given the vast amount of information available on the Web, it is customary to answer queries with only a small set of results (typically 10 or 20 pages at most). Search engines must then rank Web pages, in order to create a short list of high-quality results for users. Web spam can significantly deteriorate the quality of search engine results. Thus there is a large incentive for commercial search engines to detect spam pages efficiently and accurately. Here we present the main techniques recently introduced for Web Spam detection e demotion. 1

Abstract-The paper aims at examining malicious spyware that are causing a significant threat to desktop security and are playing with the integrity of the system. The misuse of websites to serve exploit code to compromise hosts on the Internet has increased drastically in the recent years. Many approaches to tackle the problem of spam have been proposed. Spamming is any deliberate action solely in order to boost a web page’s position in search engine results, incommensurate with page’s real value. Web Spam is the Web pages that are the result of spamming. Web spam is the deliberate manipulation of search engine indexes. It is one of the search engine optimization methods. The paper provides an efficient way that prevents users from browsing malicious Web sites by providing a service to check a Web site for malignity before the user opens it. Hence if a Web site has been reported to be malicious, the browser can warn the user and suggest not visiting it.