As few seats are still available for next session of the Android training [1], we setup a crackme challenge for which you have to find the correct phone number that leads to the following message:

Quarkslab's new internships season is open! Like every year, we are looking for adventurous, motivated and courageous students, impatient to test their skills against real-life research and engineering problems. The topics we propose cover various aspects of the security field, and they all have in common being highly technical, complex and challenging. Be prepared to work hard for your own enjoyment: the satisfaction when overcoming such difficulties is priceless. As an intern, you will work among the amazing Qb crew, whose humour is also priceless.

All internships will take place in our main office in Paris, France. If you are coming from abroad, you will need a proper visa to be with us. At Quarkslab, we encourage remote work, but that does not apply to internships.

Last but not least, we usually train Padawans so that they stay with us once their training period is done, even if that does not mean the training is over :)

This blogpost briefly presents the Windows Notification Facility and provides a write-up for a nice exercise that was given by Bruce Dang during his workshop at Recon Montreal 2018.

Quarkslab team performed a cryptographic & security assessment of the Bulletproof protocol, a new non-interactive zero-knowledge proof protocol, to be used by the Monero open-source cryptocurrency (XMR). We found several issues, some possibly critical, during the analysis.

CPUs used to perform better when memory accesses are aligned, that is when the pointer value is a multiple of the alignment value. This differentiation still exists in current CPUs, and still some have only instructions that perform aligned accesses. To take into account this issue, the C standard has alignment rules in place, and so the compilers exploit them to generate efficient code whenever possible. As we will see in this article, we need to be careful while casting pointers around to be sure not to break any of these rules. The goal of this article is to be educative by showcasing the problem and by giving some solutions to easily get over it.

Two engineers from QuarksLab had talks accepted at CppCon this year: two tools presentation, Easy::jit, and Frozen; and a general introduction to the ELF format. It's hard to cope with the 9 hours of jet-lag, but it is definitively worth the effort, so here is our conf report!

In this blog post we compare the post-exploitation process of two jailbreaks for iOS 11.1.2 : LiberiOS and Electra. We start by giving a quick refresher about jailbreaks, and then proceed with the description of their implementation.

This blog post provides the reader with an overview of the Intel SGX technology, as a follow-up to SGX Internals. In this second part, we quickly explain how an application interacts with its enclave. We also detail what pieces of software are included within the SDK and PSW. Finally, we summarize the known attacks and concerns with this technology, as well as conclude on the subject.

An overview of the TrustZone was given in a previous article. This second article more technically addresses the attack surface and hotspots exposed to an attacker, as well as what can be done once code execution is achieved in the different privilege levels available in TrustZone.

Earlier this year, on March 2018, we published a blog post detailing 2 vulnerabilities in the Android Bluetooth stack, which were independently discovered by Quarkslab, but were fixed in the March 2018 Android Security Bulletin while we were in the process of reporting them to Google.