Breaking, Misc

fpicker: Fuzzing with Frida

Introduction

In this post, I will introduce fpicker. Fpicker is a Frida-based coverage-guided, mostly in-process, blackbox fuzzing suite. Its most significant feature is the AFL++ proxy mode which enables blackbox in-process fuzzing with AFL++ on platforms supported by Frida. In practice, this means that fpicker enables fuzzing binary-only targets with AFL++ on potentially any system that is supported by Frida. For example, it allows fuzzing a user-space application on the iOS operating system, such as the Bluetooth daemon bluetoothd – which was part of the original motivation to implement fpicker.

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Breaking

Dumping Decrypted Documents from a North Korean PDF Reader

This is a write-up about how to use Frida to dump documents from a process after they have been loaded and decrypted. It’s a generic and very effective approach demonstrated on a piece of software from North Korea.

Some time ago we received an ISO file which was a dump of a CD-ROM from North Korea. The only information we got was that it included a document viewer and various PDF documents. I started to dump the content of the ISO in order to analyze what the reader was actually doing by mounting it:

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