R. Thomas Profile

Romain Thomas

Security Engineer

Reverse Engineering

Tooling

Code Obfuscation

Training

I'm a security engineer interested in reverse-engineering, code obfuscation, software protections, and tools development.

I develop and maintain LIEF, a library to parse and manipulate executable formats and I'm also working on Open-Obfuscator, a free and open-source obfuscator for mobile applications.

I enjoy going back and forth between reverse-engineering and tooling. I started at Quarkslab back in 2016 where I had the chance to work on various topics from JTAG ports detection to the support of AArch64 in QBDI. I also participated in the bootstrapping of an Android training covering both: system internals and app analysis. I left the company in 2021 to work on the security of banking applications. This new topic involves code obfuscation and software protection analysis from the perspective of EMVCo certifications.

Interests

  • Reverse engineering
  • Cryptography
  • Executable file formats
  • Mobile applications & internals
  • Obfuscation
  • Privacy
  • Protocols Analysis

Blog Posts

 Feed

April 28, 2025
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Fuzzing Windows ARM64 closed-source binary

This blog post introduces coverage-guided fuzzing with QBDI and libFuzzer targeting Windows ARM64.

September 29, 2024
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Instrumenting an Apple Vision Pro Library with QBDI

This blog post demonstrates how to extract liblockdown.dylib from the visionOS dyld shared cache to be instrumented with QBDI on an Apple M1.

January 4, 2023
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iCDump: A Modern Objective-C Class Dump

This blog post introduces iCDump, an new Objective-C class dump based on LLVM

Projects

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iCDump

iCDump is a cross-platform Objective-C class dump

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Open-Obfuscator

A free and open-source obfuscator for mobile applications

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QBDL

QuarkslaB Dynamic Loader: Generic loader for ELF, PE and Mach-O

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Tencent Legu Unpacker

Scripts to unpack Android applications protected by Tencent Legu

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Android Runtime Restrictions Bypass (PoC)

Android application that disables Android restrictions without root privileges

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LIEF

LIEF is a Library to Instrument Executable Formats

Publications

Conferences & White Papers

The Poor Man's Obfuscator

The Poor Man's Obfuscator

The purpose of this publication is to present ELF and Mach-O transformations which impact or hinder disassemblers like IDA, BinaryNinja, Ghidra, and Radare2.

Pass The Salt
Romain Thomas
July 4, 2022
DroidGuard: A Deep Dive into SafetyNet

DroidGuard: A Deep Dive into SafetyNet

SafetyNet is the Android component developed by Google to verify the devices’ integrity. These checks are used by the developers to prevent running applications on devices that would not meet security requirements but it is also used by Google …

SSTIC & BlackHat Asia
Romain Thomas
May 12, 2022
PGSharp: Analysis of a Cheat Engine on Android

PGSharp: Analysis of a Cheat Engine on Android

PGSharp is a cheating app for PokemonGO that works on non-rooted devices. This talk introduces its functionalities and the protections used to prevent reverse-engineering.

Ekoparty
Romain Thomas
November 5, 2021

Trainings & Workshops

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    Introduction to Reverse Engineering

    Workshop

    This workshop aims to provide the key concepts in reverse engineering to address the main challenges …

Misc

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