Game of Registrars: An Empirical Analysis of Post-Expiration Domain Name Takeovers


Tobias Lauinger, Northeastern University; Abdelberi Chaabane, Nokia Bell Labs; Ahmet Salih Buyukkayhan, Northeastern University; Kaan Onarlioglu,; William Robertson, Northeastern University


Every day, hundreds of thousands of Internet domain names are abandoned by their owners and become available for re-registration. Yet, there appears to be enough residual value and demand from domain speculators to give rise to a highly competitive ecosystem of drop-catch services that race to be the first to re-register potentially desirable domain names in the very instant the old registration is deleted. To pre-empt the competitive (and uncertain) race to re-registration, some registrars sell their own customers’ expired domains pre-release, that is, even before the names are returned to general availability.

These practices are not without controversy, and can have serious security consequences. In this paper, we present an empirical analysis of these two kinds of post-expiration domain ownership changes.We find that 10% of all com domains are re-registered on the same day as their old registration is deleted. In the case of org, over 50% of re-registrations on the deletion day occur during only 30 s. Furthermore, drop-catch services control over 75% of accredited domain registrars and cause more than 80% of domain creation attempts, but represent at most 9.5% of successful domain creations. These findings highlight a significant demand for expired domains, and hint at highly competitive re-registrations.

Our work sheds light on various questionable practices in an opaque ecosystem. The implications go beyond the annoyance of websites turned into “Internet graffiti”, as domain ownership changes have the potential to circumvent established security mechanisms.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {203644,
author = {Tobias Lauinger and Abdelberi Chaabane and Ahmet Salih Buyukkayhan and Kaan Onarlioglu and William Robertson},
title = {Game of Registrars: An Empirical Analysis of {Post-Expiration} Domain Name Takeovers},
booktitle = {26th USENIX Security Symposium (USENIX Security 17)},
year = {2017},
isbn = {978-1-931971-40-9},
address = {Vancouver, BC},
pages = {865--880},
url = {},
publisher = {USENIX Association},
month = aug

Presentation Video