A Study of URL Redirection Indicating Spam
Krishna Bhargrava, Douglas Brewer · 2009
The use of URL redirections has been recently studied to filter spam as email and web spammers use redirection to camouflage their web pages. However, many web sites also employ redirection for legitimate reasons such as logging, localization, and load-balancing. While a majority of the studies on URL redirection focused on spam redirection, we provide a holistic view of the use of URL redirections in the Internet. We performed a redirection study on vari-ous sets of known legitimate URLs and spam URLs. We observed that URL redirections are widely used with more than 40 % of legitimate URLs redirecting for various reasons. We also observed that server side redirection is prominent in both legitimate and spam redirection. Differing from le-gitimate URL redirection, JavaScript redirection is detected more often in spam URLs. Furthermore, a very high per-centage of spam redirections lead to an external domain. We expect that our measurement results and classifications provide a better understanding of the usage of URL redi-rection, which could help improve spam filtering and other applications that rely on URLs. 1.