Dissecting Mobile Offerwall Advertisements: An Explorative Study

Mobile advertising has become the most popular monetizing way in the Android app ecosystem. Offerwall, as a new form of mobile ads, has been widely adopted by apps, and a number of ad networks have provided such services. Although new to the ecosystem, offerwall ads have been criticized for being aggressive, and the contents disseminated are prone to security issues. However, to date, our community has not proposed any studies to dissect such issues related to offerwall ads. To this end, we present the first work to fill this gap. Specifically, we first develop a robust approach to identify apps that have embedded with offerwall ads. Then, we apply the tool to 10K apps and experimentally discover 312 offerwall apps. We go one step further to characterize them from several aspects, including security issues. Our observation reveals that offerwall ads could indeed be manipulated by hackers to fulfill malicious purposes.