Richard Clayton and I recently presented evidence of the adverse impact of take-down companies not sharing phishing feeds. Many phishing websites are missed by the take-down company which has the contract for removal; unsurprisingly, these websites are not removed very fast. Consequently, more consumers’ identities are stolen.
In the paper, we propose a simple solution: take-down companies should share their raw, unverified feeds of phishing URLs with their competitors. Each company can examine the raw feed, pick out the websites impersonating their clients, and focus on removing these sites.
Since we presented our findings to the Anti-Phishing Working Group eCrime Researchers Summit, we have received considerable feedback from take-down companies. Take-down companies attending the APWG meeting understood that sharing would help speed up response times, but expressed reservations at sharing their feeds unless they were duly compensated. Eric Olsen of Cyveillance (another company offering take-down services) has written a comprehensive rebuttal of our recommendations. He argues that competition between take-down companies drives investment in efforts to detect more websites. Mandated sharing of phishing URL feeds, in his view, would undermine these detection efforts and cause take-down companies such as Cyveillance to exit the business.
I do have some sympathy for the objections raised by the take-down companies. As we state in the paper, free-riding (where one company relies on another to invest in detection so they don’t have to) is a concern for any sharing regime. Academic research studying other areas of information security (e.g., here and here), however, has shown that free-riding is unlikely to be so rampant as to drive all the best take-down companies out of offering service, as Mr. Olsen suggests.
While we can quibble over the extent of the threat from free free-riding, it should not detract from the conclusions we draw over the need for greater sharing. In our view, it would be unwise and irresponsible to accept the current status quo of keeping phishing URL feeds completely private. After all, competition without sharing has approximately doubled the lifetimes of phishing websites! The solution, then, is to devise a sharing mechanism that gives take-down companies the incentive to keep detecting more phishing URLs.