—A parked domain is an undeveloped domain which has no content other than automatically computed advertising banners and links, used to generate profit. Despite the apparent popularity of this practice, little is known about parked domains and domain parking services that assist domain owners in parking and monetizing unused domains. This paper presents and in-depth exploration of the ecosystem of domain parking services from a security point of view, focusing mostly on the consequences for everyday users who land on parked pages. By collecting data from over 8 million parked domains, we are able to map out the entities that constitute the ecosystem, thus allowing us to analyze the domain owners, parking services, and advertisement syndicators involved. We show that users who land on parked websites are exposed to malware, inappropriate content, and elaborate scams, such as fake antivirus warnings and costly remote “technicians”. At the same time, we find a significant number ...