Examining the impact of website take-down on phishing

Banks and other organisations deal with fraudulent phishing websites by pressing hosting service providers to remove the sites from the Internet. Until they are removed, the fraudsters learn the passwords, personal identification numbers (PINs) and other personal details of the users who are fooled into visiting them. We analyse empirical data on phishing website removal times and the number of visitors that the websites attract, and conclude that website removal is part of the answer to phishing, but it is not fast enough to completely mitigate the problem. The removal times have a good fit to a lognormal distribution, but within the general pattern there is ample evidence that some service providers are faster than others at removing sites, and that some brands can get fraudulent sites removed more quickly. We particularly examine a major subset of phishing websites (operated by the 'rock-phish' gang) which accounts for around half of all phishing activity and whose architectural innovations have extended their average lifetime. Finally, we provide a ballpark estimate of the total loss being suffered by the banking sector from the phishing websites we observed.