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Generic anomalous vertices detection utilizing a link prediction algorithm


In the past decade, graph-based structures have penetrated nearly every aspect of our lives. The detection of anomalies in these networks has become increasingly important, such as in exposing infected endpoints in computer networks or identifying socialbots. In this study, we present a novel unsupervised two-layered meta-classifier that can detect irregular vertices in complex networks solely by utilizing topology-based features. Following the reasoning that a vertex with many improbable links has a higher likelihood of being anomalous, we applied our method on 10 networks of various scales, from a network of several dozen students to online networks with millions of vertices. In every scenario, we succeeded in identifying anomalous vertices with lower false positive rates and higher AUCs compared to other prevalent methods. Moreover, we demonstrated that the presented algorithm is generic, and efficient both in revealing fake users and in disclosing the influential people in social networks.

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  2. In a large dataset, computing dozens of features can last several hours or even several days; to avoid extremely long computations we used only computationally efficient features (Fire et al. 2013).

  3. This not the standard kNN acronym, but a set of weight functions defined by Cukierski et al. (2011).










  13. We limited the crawler to crawling a maximum of 1000 friends and followers for every profile (see Sect. 9). This limitation is due to the fact that Twitter accounts can have an unlimited number of friends and followers, which in some cases can reach several million.





  18. A Sybil attack is when the adversary controls a substantial fraction of the vertices in the system, which are then used to influence and manipulate the system to achieve the end goals of the attacker.




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We would like to thank Carol Teegarden and Robin Levy-Stevenson for editing and proofreading this article to completion. We also thank the Washington Research Foundation Fund for Innovation in Data-Intensive Discovery, and the Moore/Sloan Data Science Environment Project at the University of Washington for supporting this study. Finally, we would like to thank the anonymous reviewers for their helpful comments.

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Correspondence to Dima Kagan.

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Kagan, D., Elovichi, Y. & Fire, M. Generic anomalous vertices detection utilizing a link prediction algorithm. Soc. Netw. Anal. Min. 8, 27 (2018).

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  • Anomalous Vertex
  • Classical Link Prediction
  • Anomaly Detection
  • Fake Profiles
  • Transit Friendly