Funny Accents: Exploring Genuine Interest in Internationalized Domain Names

Abstract

International Domain Names (IDNs) were introduced to support non-ASCII characters in domain names. In this paper, we explore IDNs that hold genuine interest, i.e. that owners of brands with diacritical marks may want to register and use. We generate 15 276 candidate IDNs from the page titles of popular domains, and see that 43% are readily available for registration, allowing for spoofing or phishing attacks. Meanwhile, 9% are not allowed by the respective registry to be registered, preventing brand owners from owning the IDN. Based on WHOIS records, DNS records and a web crawl, we estimate that at least 50% of the 3 189 registered IDNs have the same owner as the original domain, but that 35% are owned by a different entity, mainly domain squatters; malicious activity was not observed. Finally, we see that application behavior toward these IDNs remains inconsistent, hindering user experience and therefore widespread uptake of IDNs, and even uncover a phishing vulnerability in iOS Mail.