Longitudinal Analysis of Android Ad Library Permissions

TL;DR

This study tracks how Android ad libraries' permission usage has evolved over time, revealing increased privacy and security risks due to more libraries gaining access to sensitive permissions.

Contribution

It introduces a method to chronologically map ad library permissions over time using app release dates, highlighting trends in permission usage.

Findings

Permissions used by ad libraries have increased over recent years.

More ad libraries now access permissions that threaten user privacy.

The overall risk profile of ad libraries has grown over time.

Abstract

This paper investigates changes over time in the behavior of Android ad libraries. Taking a sample of 100,000 apps, we extract and classify the ad libraries. By considering the release dates of the applications that use a specific ad library version, we estimate the release date for the library, and thus build a chronological map of the permissions used by various ad libraries over time. We find that the use of most permissions has increased over the last several years, and that more libraries are able to use permissions that pose particular risks to user privacy and security.