Arman Noroozian

Samaneh Tajalizadehkhoob, Tom van Goethem, Maciej Korczyński et al.

Hosting providers play a key role in fighting web compromise, but their ability to prevent abuse is constrained by the security practices of their own customers. {\em Shared} hosting, offers a unique perspective since customers operate under restricted privileges and providers retain more control over configurations. We present the first empirical analysis of the distribution of web security features and software patching practices in shared hosting providers, the influence of providers on these security practices, and their impact on web compromise rates. We construct provider-level features on the global market for shared hosting -- containing 1,259 providers -- by gathering indicators from 442,684 domains. Exploratory factor analysis of 15 indicators identifies four main latent factors that capture security efforts: content security, webmaster security, web infrastructure security and web application security. We confirm, via a fixed-effect regression model, that providers exert significant influence over the latter two factors, which are both related to the software stack in their hosting environment. Finally, by means of GLM regression analysis of these factors on phishing and malware abuse, we show that the four security and software patching factors explain between 10\% and 19\% of the variance in abuse at providers, after controlling for size. For web-application security for instance, we found that when a provider moves from the bottom 10\% to the best-performing 10\%, it would experience 4 times fewer phishing incidents. We show that providers have influence over patch levels--even higher in the stack, where CMSes can run as client-side software--and that this influence is tied to a substantial reduction in abuse levels.

Arman Noroozian, Maciej Korczyński, Samaneh TajalizadehKhoob et al.

Research into cybercrime often points to concentrations of abuse at certain hosting providers. The implication is that these providers are worse in terms of security; some are considered `bad' or even `bullet proof'. Remarkably little work exists on systematically comparing the security performance of providers. Existing metrics typically count instances of abuse and sometimes normalize these counts by taking into account the advertised address space of the provider. None of these attempts have worked through the serious methodological challenges that plague metric design. In this paper we present a systematic approach for metrics development and identify the main challenges: (i) identification of providers, (ii) abuse data coverage and quality, (iii) normalization, (iv) aggregation and (v) metric interpretation. We describe a pragmatic approach to deal with these challenges. In the process, we answer an urgent question posed to us by the Dutch police: `which are the worst providers in our jurisdiction?'. Notwithstanding their limitations, there is a clear need for security metrics for hosting providers in the fight against cybercrime.