A Statistical Analysis of DNS Abuse in New Gtlds
Total Page:16
File Type:pdf, Size:1020Kb
Cybercrime After the Sunrise: A Statistical Analysis of DNS Abuse in New gTLDs Maciej Korczyński, Maarten Wullink, Samaneh Tajalizadehkhoob, Giovane C. M. Moura Arman Noroozian, Drew Bagley, and Cristian Hesselman [email protected] ABSTRACT 1 INTRODUCTION To enhance competition and choice in the domain name system, Starting in 2007, The Internet Corporation for Assigned Names ICANN introduced the new gTLD program, which added hundreds and Numbers (ICANN) introduced the new Generic Top-Level Do- of new gTLDs (e.g. .nyc, .io) to the root DNS zone. While the pro- main (gTLD) program1, which enabled hundreds of new gTLDs to gram arguably increased the range of domain names available to enter the domain name system (DNS) since the first delegations. consumers, it might also have created new opportunities for cy- More than 1,900 applications for new gTLDs were filed after the bercriminals. To investigate that, we present the first comparative process opened in 2012. To date, more than 1,200 new gTLDs have study of abuse in the domains registered under the new gTLD pro- been delegated to the DNS root zone (e.g.: .nyc, .io). This expan- gram and legacy gTLDs (18 in total, such as .com, .org). We combine sion of the domain name space not only offers a wide range of historical datasets from various sources, including DNS zone files, options for consumers, but also potentially provides new avenues WHOIS records, passive and active DNS and HTTP measurements, for cybercriminals to abuse domain names. Anticipating potential and 11 reputable abuse feeds to study abuse across gTLDs. We find problems, ICANN has also built safeguards into the program in an that the new gTLDs appear to have diverted abuse from the legacy attempt to mitigate the prospect of abusive, malicious, and criminal gTLDs: while the total number of domains abused for spam remains activity in these new gTLDs, such as phishing, spam, and malware stable across gTLDs, we observe a growing number of spam do- distribution2. mains in new gTLDs which suggests a shift from legacy gTLDs to In a previous study, Halvorson et al. [10] concluded that spec- new gTLDs. Although legacy gTLDs had a rate of 56.9 spam do- ulative and defensive registrations dominate the growth of regis- mains per 10,000 registrations (Q4 2016), new gTLDs experienced trations in new gTLDs. Their work, however, provides very little a rate of 526.6 in the same period–which is almost one order of empirical information about the security of new gTLDs. In this magnitude higher. In this study, we also analyze the relationship paper, we investigate the following research question: how do abuse between DNS abuse, operator security indicators and the structural rates in the new gTLDs compare to legacy gTLDs, since the imple- properties of new gTLDs. The results indicate that there is an in- mentation of the new gTLD program? We take into account the new verse correlation between abuse and stricter registration policies. gTLDs as well the different parts of the industry involved: registries, Our findings suggest that cybercriminals increasingly prefer to reg- registrars, and privacy/proxy service providers. ister, rather than hack, domain names and some new gTLDs have To this end, we combine multiple datasets from various sources become a magnet for malicious actors. ICANN is currently using including zone files, domain name WHOIS records, data obtained these results to review the existing anti-abuse safeguards, evaluate through active measurements, and 11 abuse feeds provided to us their joint effects and to introduce more effective safeguards before by 5 reputable organizations. These represent malware, phishing, an upcoming new gTLD rollout. and spam abuse and cover a three-year period from 2014 to 2016. Overall, our main contributions can be summarized as follows: KEYWORDS • The research offers a comprehensive descriptive statistical com- Security Metrics, DNS, Top-Level Domains, Registrars, Cybercrime parison of rates of domain name abuse in new and legacy gTLDs ACM Reference Format: as associated with spam, phishing, and malware distribution Maciej Korczyński, Maarten Wullink, Samaneh Tajalizadehkhoob, Giovane (§5.1) to evaluate joint effects of the existing anti-abuse safe- C. M. Moura Arman Noroozian, Drew Bagley, and Cristian Hesselman. guards. 2018. Cybercrime After the Sunrise: A Statistical Analysis of DNS Abuse in • Using regression modeling we perform inferential statistical New gTLDs. In ASIA CCS ’18: 2018 ACM Asia Conference on Computer and analysis to test the correlation between passively and actively Communications Security, June 4–8, 2018, Incheon, Republic of Korea. ACM, measured properties of new gTLDs as predictors of abuse rates New York, NY, USA, 15 pages. https://doi.org/10.1145/3196494.3196548 (§5.2). • We analyze proportions of abusive domains across other enti- Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed ties relevant to abuse prevention practices, i.e. registrars and for profit or commercial advantage and that copies bear this notice and the full citation privacy/proxy providers (§5.3 and §5.4). on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, Our findings reveal surprising, previously unknown trends that to post on servers or to redistribute to lists, requires prior specific permission and/or a are relevant since new gTLDs operate on the basis of different busi- fee. Request permissions from [email protected]. ASIA CCS ’18, June 4–8, 2018, Incheon, Republic of Korea ness models and history in comparison to legacy gTLDs. While © 2018 Association for Computing Machinery. ACM ISBN 978-1-4503-5576-6/18/06...$15.00 1https://gnso.icann.org/en/group-activities/inactive/2007/new-gtld-intro https://doi.org/10.1145/3196494.3196548 2https://newgtlds.icann.org/en/reviews/cct/dns-abuse patterns of abuse vary with respect to abuse type, our analysis sug- later. The initial group of gTLDs (.gov, .edu, .com, .mil, .org, and gests that the total number of spam domains in all gTLDs remains .net) were distinct from country-code TLDs (ccTLDs). Until 2012, relatively constant. Simultaneously, the number of spam domains several gTLDs were approved and further introduced by ICANN, in new gTLDs is higher (Q4 2016) and growing. We also observe including a set of sponsored gTLDs such as .asia, .jobs, .travel, a significant decrease in the number of malicious registrations in or .mobi. We refer to all gTLDs introduced before the new gTLD legacy gTLDs (§5.1.7). Therefore, we see a new trend: attackers program initiated by ICANN in late 2013 as legacy gTLDs. This switching from abusing legacy to new gTLD domain name space. study analyzes a set of 18 legacy gTLDs (.aero, .asia, .biz, .cat, .com, Our analysis of the Spamhaus blacklist also reveals that in the .coop, .info, .jobs, .mobi, .museum, .name, .net, .org, .post, .pro, .tel, last quarter of 2016, new gTLDs collectively had approximately .travel, and .xxx), for which we were able to obtain zone files and one order of magnitude higher rate of spam domains per 10,000 WHOIS data, and compare them to new gTLDs. registrations compared to legacy gTLDs (§5.1.8). This research also systematically analyzes how different struc- 2.2 New gTLDs tural and security-related properties of new gTLD operators in- ICANN’s new gTLD program began in 2012, expanding the root fluence abuse counts. Our inferential analysis reveals that abuse zone by delegating more than 1,200 new gTLDs starting in October counts inversely correlate with the restrictiveness of registration 2013 [22]. To obtain a new gTLD, applicants are required to undergo policies (§5.2). The analysis of abuse across new gTLDs, registrars, an intensive application and evaluation process [10] that includes and privacy/proxy service providers reveals discrete entities af- screening the applicants technical and financial capabilities for op- flicted with significantly high concentrations of abused domains. erating a new gTLD. Ultimately, after a new gTLD is assigned to an We find new gTLDs and registrars with concentrations of black- applicant, it will then be delegated to the root zone. Following initial listed domains above 50% (§5.1.8 and §5.4). For one registrar, more delegation, each new gTLD registry is required to have a “sunrise” than 93% of its domains were reported as abusive by SURBL. period of at least 30 days, during which trademark holders have an ICANN may further expand the number of gTLDs available. advance opportunity to register domain names corresponding to Therefore, it is important to understand how miscreants are using their marks, before the names are generally available to the public. the expanded domain name space in their favor. Finally, as the New gTLDs can be classified into four broad categories [22]3: presented state of the art in gTLD abuse is in clear need of improve- • Standard or generic gTLD: gTLDs that are generally open for ment, we develop cases for modifying the existing safeguards and public registration, e.g. .movie, .xyz, or .family4 proposing new ones. This work is a corollary to our analysis that • Geographic gTLD: gTLDs that cover cities, states, or regions, ICANN is currently using to review the existing anti-abuse safe- e.g. .amsterdam or .berlin. guards, evaluate their joint effects and to introduce more effective • Community gTLD: gTLDs that are restricted to a specific com- ones before an upcoming new gTLD rollout [27]. munity, such as .thai, .radio or .pharmacy. 2 BACKGROUND • Brand gTLD: gTLDs specific to a company or a brand, suchas .google or .hitachi.