4,519 research outputs found
After Over-Privileged Permissions: Using Technology and Design to Create Legal Compliance
Consumers in the mobile ecosystem can putatively protect their privacy with the use of application permissions. However, this requires the mobile device owners to understand permissions and their privacy implications. Yet, few consumers appreciate the nature of permissions within the mobile ecosystem, often failing to appreciate the privacy permissions that are altered when updating an app. Even more concerning is the lack of understanding of the wide use of third-party libraries, most which are installed with automatic permissions, that is permissions that must be granted to allow the application to function appropriately. Unsurprisingly, many of these third-party permissions violate consumers’ privacy expectations and thereby, become “over-privileged” to the user. Consequently, an obscurity of privacy expectations between what is practiced by the private sector and what is deemed appropriate by the public sector is exhibited. Despite the growing attention given to privacy in the mobile ecosystem, legal literature has largely ignored the implications of mobile permissions. This article seeks to address this omission by analyzing the impacts of mobile permissions and the privacy harms experienced by consumers of mobile applications. The authors call for the review of industry self-regulation and the overreliance upon simple notice and consent. Instead, the authors set out a plan for greater attention to be paid to socio-technical solutions, focusing on better privacy protections and technology embedded within the automatic permission-based application ecosystem
Do Androids Dream of Electric Sheep? On Privacy in the Android Supply Chain
The Android Open Source Project (AOSP) was first released by Google in 2008 and
has since become the most used operating system [Andaf]. Thanks to the openness
of its source code, any smartphone vendor or original equipment manufacturer
(OEM) can modify and adapt Android to their specific needs, or add proprietary features
before installing it on their devices in order to add custom features to differentiate themselves
from competitors. This has created a complex and diverse supply chain, completely opaque to
end-users, formed by manufacturers, resellers, chipset manufacturers, network operators, and
prominent actors of the online industry that partnered with OEMs. Each of these stakeholders
can pre-install extra apps, or implement proprietary features at the framework level.
However, such customizations can create privacy and security threats to end-users. Preinstalled
apps are privileged by the operating system, and can therefore access system APIs
or personal data more easily than apps installed by the user. Unfortunately, despite these
potential threats, there is currently no end-to-end control over what apps come pre-installed
on a device and why, and no traceability of the different software and hardware components
used in a given Android device. In fact, the landscape of pre-installed software in Android and
its security and privacy implications has largely remained unexplored by researchers.
In this thesis, I investigate the customization of Android devices and their impact on the
privacy and security of end-users. Specifically, I perform the first large-scale and systematic
analysis of pre-installed Android apps and the supply chain. To do so, I first develop an app,
Firmware Scanner [Sca], to crowdsource close to 34,000 Android firmware versions from 1,000
different OEMs from all over the world. This dataset allows us to map the stakeholders involved
in the supply chain and their relationships, from device manufacturers and mobile network operators
to third-party organizations like advertising and tracking services, and social network
platforms. I could identify multiple cases of privacy-invasive and potentially harmful behaviors.
My results show a disturbing lack of transparency and control over the Android supply
chain, thus showing that it can be damageable privacy- and security-wise to end-users.
Next, I study the evolution of the Android permission system, an essential security feature of the Android framework. Coupled with other protection mechanisms such as process sandboxing,
the permission system empowers users to control what sensitive resources (e.g., user
contacts, the camera, location sensors) are accessible to which apps. The research community
has extensively studied the permission system, but most previous studies focus on its limitations
or specific attacks. In this thesis, I present an up-to-date view and longitudinal analysis
of the evolution of the permissions system. I study how some lesser-known features of the
permission system, specifically permission flags, can impact the permission granting process,
making it either more restrictive or less. I then highlight how pre-installed apps developers
use said flags in the wild and focus on the privacy and security implications. Specifically, I
show the presence of third-party apps, installed as privileged system apps, potentially using
said features to share resources with other third-party apps.
Another salient feature of the permission system is its extensibility: apps can define their
own custom permissions to expose features and data to other apps. However, little is known
about how widespread the usage of custom permissions is, and what impact these permissions
may have on users’ privacy and security. In the last part of this thesis, I investigate the exposure
and request of custom permissions in the Android ecosystem and their potential for opening
privacy and security risks. I gather a 2.2-million-app-large dataset of both pre-installed and
publicly available apps using both Firmware Scanner and purpose-built app store crawlers.
I find the usage of custom permissions to be pervasive, regardless of the origin of the apps,
and seemingly growing over time. Despite this prevalence, I find that custom permissions are
virtually invisible to end-users, and their purpose is mostly undocumented. While Google recommends
that developers use their reverse domain name as the prefix of their custom permissions
[Gpla], I find widespread violations of this recommendation, making sound attribution
at scale virtually impossible. Through static analysis methods, I demonstrate that custom permissions
can facilitate access to permission-protected system resources to apps that lack those
permissions, without user awareness. Due to the lack of tools for studying such risks, I design
and implement two tools, PermissionTracer [Pere] and PermissionTainter [Perd] to study
custom permissions. I highlight multiple cases of concerning use of custom permissions by
Android apps in the wild.
In this thesis, I systematically studied, at scale, the vast and overlooked ecosystem of preinstalled
Android apps. My results show a complete lack of control of the supply chain which
is worrying, given the huge potential impact of pre-installed apps on the privacy and security
of end-users. I conclude with a number of open research questions and future avenues for
further research in the ecosystem of the supply chain of Android devices.This work has been supported by IMDEA Networks InstitutePrograma de Doctorado en IngenierĂa Telemática por la Universidad Carlos III de MadridPresidente: Douglas Leith.- Secretario: RubĂ©n Cuevas RumĂn.- Vocal: Hamed Haddad
Eight years of rider measurement in the Android malware ecosystem: evolution and lessons learned
Despite the growing threat posed by Android malware,
the research community is still lacking a comprehensive
view of common behaviors and trends exposed by malware families
active on the platform. Without such view, the researchers
incur the risk of developing systems that only detect outdated
threats, missing the most recent ones. In this paper, we conduct
the largest measurement of Android malware behavior to date,
analyzing over 1.2 million malware samples that belong to 1.2K
families over a period of eight years (from 2010 to 2017). We
aim at understanding how the behavior of Android malware
has evolved over time, focusing on repackaging malware. In
this type of threats different innocuous apps are piggybacked
with a malicious payload (rider), allowing inexpensive malware
manufacturing.
One of the main challenges posed when studying repackaged
malware is slicing the app to split benign components apart from
the malicious ones. To address this problem, we use differential
analysis to isolate software components that are irrelevant to the
campaign and study the behavior of malicious riders alone. Our
analysis framework relies on collective repositories and recent
advances on the systematization of intelligence extracted from
multiple anti-virus vendors. We find that since its infancy in
2010, the Android malware ecosystem has changed significantly,
both in the type of malicious activity performed by the malicious
samples and in the level of obfuscation used by malware to avoid
detection. We then show that our framework can aid analysts
who attempt to study unknown malware families. Finally, we
discuss what our findings mean for Android malware detection
research, highlighting areas that need further attention by the
research community.Accepted manuscrip
Overcoming Language Dichotomies: Toward Effective Program Comprehension for Mobile App Development
Mobile devices and platforms have become an established target for modern
software developers due to performant hardware and a large and growing user
base numbering in the billions. Despite their popularity, the software
development process for mobile apps comes with a set of unique, domain-specific
challenges rooted in program comprehension. Many of these challenges stem from
developer difficulties in reasoning about different representations of a
program, a phenomenon we define as a "language dichotomy". In this paper, we
reflect upon the various language dichotomies that contribute to open problems
in program comprehension and development for mobile apps. Furthermore, to help
guide the research community towards effective solutions for these problems, we
provide a roadmap of directions for future work.Comment: Invited Keynote Paper for the 26th IEEE/ACM International Conference
on Program Comprehension (ICPC'18
Third Party Tracking in the Mobile Ecosystem
Third party tracking allows companies to identify users and track their
behaviour across multiple digital services. This paper presents an empirical
study of the prevalence of third-party trackers on 959,000 apps from the US and
UK Google Play stores. We find that most apps contain third party tracking, and
the distribution of trackers is long-tailed with several highly dominant
trackers accounting for a large portion of the coverage. The extent of tracking
also differs between categories of apps; in particular, news apps and apps
targeted at children appear to be amongst the worst in terms of the number of
third party trackers associated with them. Third party tracking is also
revealed to be a highly trans-national phenomenon, with many trackers operating
in jurisdictions outside the EU. Based on these findings, we draw out some
significant legal compliance challenges facing the tracking industry.Comment: Corrected missing company info (Linkedin owned by Microsoft). Figures
for Microsoft and Linkedin re-calculated and added to Table
- …