Harvesting SSL Certificate Data to Mitigate Web-Fraud
Mishari Al Mishari, Emiliano De Cristofaro, Karim M. El Defrawy, Gene Tsudik · arXiv (Cornell University) · 2009
Web-fraud is one of the most unpleasant features of today’s Internet. Two eminent examples of web-fraudulent activities are phishing and typosquatting. Phishing aims to elicit sensitive information from users by presenting them with mock-ups of legitimate web sites. Typosquatting is the nefarious practice of fielding web sites with names closely resembling those of legitimate and popular Internet destinations. Effects range from relatively benign (such as unwanted or unexpected ads) to downright sinister (especially, when typosquatting is combined with phishing). Prior work has assessed the risks of phishing and typosquatting and even attempted to profile and mitigate them. However, the problem remains largely unsolved. This paper presents a novel technique to detect web-fraud domains that utilize HTTPS. To achieve this, we conduct the first comprehensive study of SSL certificates for legitimate and popular domains, as opposed to those used for web-fraud. Drawing from extensive measurements, we build a classifier that detects malicious domains with high accuracy. We validate our methodology with large amounts of data collected from the Internet. Our prototype is orthogonal to existing mitigation techniques and can be integrated with other available solutions. Our work shows that, besides its intended benefits of confidentiality and authenticity, the use of HTTPS can help mitigate web-fraud. 1