Earlier this year, two research papers reported the observation of strange phenomena in the Domain Name System (DNS) at several US ISPs. On these ISPs' networks, some or all traffic to major search engines, including Bing, Yahoo! and (sometimes) Google, is being directed to mysterious third party proxies.
A report in New Scientist today documents that the traffic is being rerouted through a company called Paxfire. This blog post, coauthored with one of the teams that discovered the phenomenon, will explain the situation in more detail.
Who is rerouting this search traffic?
The published research papers did not identify the controller of the proxy servers that were receiving the traffic, but parallel investigations by the ICSI Networking Group and EFF have since revealed a company called Paxfire as the main actor behind this interception. Paxfire's privacy policy says that it may retain copies of users' "queries", a vague term that could be construed to mean either the domain names that they look up or the searches they conduct, or both. The redirections mostly occur transparently to the user and few if any of the affected ISP customers are likely to have ever heard of Paxfire, let alone consented to this collection of their communications with search engines.
The proxies in question are operated either directly by Paxfire, or by the ISPs using web proxies provided by Paxfire. Major users of the Paxfire system include Cavalier, Cogent, Frontier, Fuse, DirecPC, RCN, and Wide Open West. Charter also used Paxfire in the past, but appears to have discontinued this practice.
Why do they do this?
In short, the purpose appears to be monetization of users' searches. ICSI Networking's investigation has revealed that Paxfire's HTTP proxies selectively siphon search requests out of the proxied traffic flows and redirect them through one or more affiliate marketing programs, presumably resulting in commission payments to Paxfire and the ISPs involved. The affiliate programs involved include Commission Junction, the Google Affiliate Network, LinkShare, and Ask.com. When looking up brand names such as "apple", "dell", "groupon", and "wsj", the affiliate programs direct the queries to the corresponding brands' websites or to search assistance pages instead of providing the intended search engine results page.
What can I do about it?If you want to know if the network you're currently on is subject to this type of traffic redirection, you can run a Netalyzr test. And the best protection against the privacy and security risks created by this type of hijacking is to visit sites using HTTPS rather than HTTP, which can easily be achieved using EFF's HTTPS Everywhere Firefox extension.
More technical details below...
