The realm of third-party trackers on Android

Luman android root cert

I was excited to learn about Lumen Privacy Monitor, as I’ve always wondered about the apps I have installed even when I have restricted the permissions wanted from the installed app.

New research co-authored by Mozilla Fellow Rishab Nithyanand explores just this: The opaque realm of third-party trackers and what they know about us. The research is titled “Apps, Trackers, Privacy, and Regulators: A Global Study of the Mobile Tracking Ecosystem,” and is authored by researchers at Stony Brook University, Data & Society, IMDEA Networks, ICSI, Princeton University, Corelight, and the University of Massachusetts Amherst.

“This is the start of a long project to uncover all the hidden data collection and data dissemination practices on the internet,” Nithyanand explains.

“There’s a huge lack of transparency around how mobile applications behave,” adds Narseo Vallina-Rodriguez, a co-author and researcher at ICSI. “People install software, but don’t know what that software is doing.”

The paper’s introduction lays out a troubling scenario: “Third-party services inherit the set of application permissions requested by the host app, allowing them access to a wealth of valuable user data, often beyond what they need to provide the expected service.”

To study this scenario, the researchers used Lumen Privacy Monitor, an Android app they built themselves over a two-year period.

So I installed it just to see what was going on with my Android devices. But there is a problem… Best summed up in this comment from Wcat.

Not open source? TLS interception? Before you install this stop and think about TLS interception. “Those who would trade privacy for security deserve neither.”

Luman asks for permissions to install its own root certificate, and this deeply worries me. TLS inception isn’t a trivial thing to be honest, I know its needed but it had me questioning how I really want to monitor the apps? Also if I remove the app, will the certificate be removed too/how would I know?

Right now, I’m keeping an eye on the app but haven’t installed the root cert yet.