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International Journal of Security




Phishing is a growing threat to Internet users and causes billions of dollars in damage every year. While there are a number of research articles that study the tactics, techniques and procedures employed by phishers in the literature, in this paper, we present a theoretical yet practical model to study this menacing threat in a formal manner. While it is common folklore knowledge that a successful phishing attack entails creating messages that are indistinguishable from the natural, expected messages by the intended victim, this concept has not been formalized. Our model attempts to capture a phishing attack in terms of this indistinguishability between the natural and phishing message probability distributions. We view the actions performed by a phisher as an attempt to create messages that are indistinguishable to the victim from that of "normal" messages. To the best of our knowledge, this is the first study that places phishing on a concrete theoretical framework and offers a new perspective to analyze this threat. We propose metrics to analyze the success probability of a phishing attack taking into account the input used by a phisher and the work involved in creating deceptive email messages. Finally, we study and apply our model to a new class of phishing attacks called collaborative spear phishing that is gaining momentum. Recent examples include Operation Woolen-Goldfish in 2015, Rocket Kitten in 2014 and Epsilon email breach in 2011. We point out fundamental flaws in the current email-based marketing business model which enables such targeted spear phishing collaborative attacks. In this sense, our study is very timely and presents new and emerging trends in phishing.


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This article was retrieved from the International Journal of Security and is licensed under Creative Commons Attribution (CC-BY).