Political campaigns are known to collect private user data, whether for building voter profiles, engaging with volunteers, or for soliciting donations. However, as such campaigns are classified as nonprofit in the United States (U.S.), their privacy practices have not received the same level of scrutiny as those of for-profit enterprises. This paper presents the Polityzer framework to evaluate the privacy posture of political campaign websites, and uses it to analyze 2060 campaign websites active during the U.S. election of November 2020. Our analysis leads to 20 key findings that demonstrate gaps in the privacy postures of political campaigns. For instance, we find that campaigns collect extensive private data they are not required to by the Federal Election Commission (FEC), and a vast majority do not provide any form of privacy disclosure. When disclosures are provided, they are often incomplete. We also found that campaigns may be inadvertently sharing data with other campaigns through common fundraising platforms, without disclosing such sharing. Reporting the lack of privacy disclosure to the respective campaigns yields further insights into the rationale behind their security posture. Finally, we discuss ways in which our results could enable future research, inform emerging privacy regulations, and transform user behavior regarding data privacy in this critical context.

Billions of users rely on the security of the Android platform to protect phones, tablets, and many different types of consumer electronics. While Android's permission model is well studied, the enforcement of the protection policy has received relatively little attention. Much of this enforcement is spread across system services, taking the form of hard-coded checks within their implementations. In this paper, we propose Authorization Check Miner (ACMiner), a framework for evaluating the correctness of Android's access control enforcement through consistency analysis of authorization checks. ACMiner combines program and text analysis techniques to generate a rich set of authorization checks, mines the corresponding protection policy for each service entry point, and uses association rule mining at a service granularity to identify inconsistencies that may correspond to vulnerabilities. We used ACMiner to study the AOSP version of Android 7.1.1 to identify 28 vulnerabilities relating to missing authorization checks. In doing so, we demonstrate ACMiner's ability to help domain experts process thousands of authorization checks scattered across millions of lines of code.

Mobile applications frequently request sensitive data. While prior work has focused on analyzing sensitive-data uses originating from well-defined API calls in the system, the security and privacy implications of inputs requested via application user interfaces have been widely unexplored. In this paper, our goal is to understand the broad implications of such requests in terms of the type of sensitive data being requested by applications.

Mobile malware attempts to evade detection during app analysis by mimicking security-sensitive behaviors of benign apps that provide similar functionality (e.g., sending SMS messages), and suppressing their payload to reduce the chance of being observed (e.g., executing only its payload at night). Since current approaches focus their analyses on the types of security-sensitive resources being accessed (e.g., network), these evasive techniques in malware make differentiating between malicious and benign app behaviors a difficult task during app analysis. We propose that the malicious and benign behaviors within apps can be differentiated based on the contexts that trigger security-sensitive behaviors, i.e., the events and conditions that cause the security-sensitive behaviors to occur. In this work, we introduce AppContext, an approach of static program analysis that extracts the contexts of security-sensitive behaviors to assist app analysis in differentiating between malicious and benign behaviors. We implement a prototype of AppContext and evaluate AppContext on 202 malicious apps from various malware datasets, and 633 benign apps from the Google Play Store. AppContext correctly identifies 192 malicious apps with 87.7% precision and 95% recall. Our evaluation results suggest that the maliciousness of a security-sensitive behavior is more closely related to the intention of the behavior (reflected via contexts) than the type of the security-sensitive resources that the behavior accesses.