The Jiu-Jitsu of Detecting Frida

Frida is hugely popular with Android reverse engineers, and for good reason: It offers runtime access to pretty much everything one could dream of, from raw memory and native functions to Java obje...

More Android Anti-Debugging Fun

In my last blog post, I talked about tampering with the virtual method tables of certain JDWP-related classes in ART. By sprinkling an app with little anti-JDWP tricks, developers can effectively s...

Anti-Debugging Fun With Android ART

Messing with JDWP-related memory structures makes for some nice and stealthy anti-debugging tricks. The first mention I saw of this method was in a 2013 presentation by Bluebox Security, who were g...

Verifying Mobile App Security Using the OWASP Checklist

Even though modern mobile operating systems like iOS and Android are arguably more secure by design compared to traditional Desktop operating systems, there's still a lot of things that can go wron...

Patching and Re-Signing iOS Apps

Running modifed iOS binaries on non-jailbroken devices can sometimes be a desirable proposition - especially if you just bricked your last jailbroken iPhone and were forced to update to a non-jailb...

Hooking Android System Calls for Pleasure and Benefit

The Android kernel is a powerful ally to the reverse engineer. While regular Android apps are hopelessly restricted and sandboxed, you - the reverser - can customize and alter the behavior of the o...

Solving an Android Crackme with a Little Symbolic Execution

Binary analysis frameworks provide you powerful ways of automating tasks that would be almost impossible to complete manually. In this blog, we'll have a look at Angr, a Python framework for analyz...

Mobile Reverse Engineering Unleashed

A series of articles, tutorials and howtos about reverse engineering mobile applications, plus other completely unrelated stuff. New articles will be added here. Index Solving an Android C...

Pentesters, Don't Overblow the Risks of Your Findings

Recently we got a call from a concerned client: A penetration testing firm engaged by one of their branch offices had reported a major vulnerability in a mobile app! The finding was in a core techn...

The OWASP MASVS: A Community Effort To Fix Mobile AppSec

Technological revolutions can happen quickly. Less than a decade ago, smartphones were clunky devices with little keyboards: Expensive playthings for tech-savvy business users. Today, smartphones a...