Reversing on Insinuator.net - Bold Statements

Windows Hello for Business – Full Report Has Been Released

Thu, 16 Jul 2026 00:00:00 +0000

Yesterday, the BSI (the German Federal Office for Information Security, or Bundesamt für Sicherheit in der Informationstechnik in German) published the first result document from the “Windows dissected” (ger.: “Windows seziert”) project: our analysis of Windows Hello for Business (WHfB). If you have followed this blog over the past year, you have seen the pieces. The full 170-page report has now been published. And it can be downloaded from the project page.

Windows Early Boot Configuration: The CmControlVector and PspSystemMitigationOptions

Mon, 13 Apr 2026 00:00:00 +0000

While investigating how process mitigation settings are initialized, I encountered the global variable PspSystemMitigationOptions. Tracing how this value is populated led me to the CmControlVector. In this blog post, we take a look at the Windows kernel land configuration manager, especially its global CmControlVector variable. Quick note: the kernel’s configuration manager is not related to Microsoft Intune’s Configuration Manager. In short, the configuration manager is responsible for managing and implementing the registry. However, it is also responsible for setting up parts of the system during early boot.

Microsoft Office Telemetry: Report Release

Tue, 17 Nov 2020 00:00:00 +0000

The German Federal Office for Information Security (orig., ger., Bundesamt für Sicherheit in der Informationstechnik – BSI) has published our report on Microsoft Office Telemetry.

Microsoft has released a set of privacy settings for Office, one of which enables users to configure the type and amount of diagnostic (i.e., telemetry) data that Office may send to Microsoft. When deployed, it is available in the form of a group policy setting. It allows users to configure one of the following diagnostic data levels: required, optional, or neither. The report we produced:

Reversing C++ Without Getting a Heart Attack – DEvirtualize VIrtual Calls With Devi

Thu, 12 Nov 2020 00:00:00 +0000

TLDR: This blogpost presents devi, a tool that can help you devirtualize virtual calls in C++ binaries. It uses Frida to trace the execution of a binary and uncover the call sources and destinations of virtual calls. The collected information can then be viewed in IDA Pro, Binary Ninja, or Ghidra. The plugin adds the respective control-flow edges allowing further analysis (using different plugins) or simply providing more comfort when analyzing C++ binaries.

Blackhoodie at TROOPERS19

Fri, 04 Jan 2019 00:00:00 +0000

We are going to have a Blackhoodie event at Troopers 2019 on March 18th and 19th in Heidelberg. With a very exciting event last year, we have decided to roll it once again during Troopers.

As always, one of the main motivation for Blackhoodie is bringing more women into reversing and other core security topics. So we would like to see more women apply to the training slots. However, if you are not a women and still feel really excited about Blackhoodie, you are welcome to apply. We do have a very limited number of seats at this training site. So we apologize in advance if we can’t accommodate everyone, even though we wish we could! Please apply before “February 10th” and we will contact you regarding next steps.

Dumping Decrypted Documents from a North Korean PDF Reader

Fri, 16 Nov 2018 00:00:00 +0000

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:

IPython Support for Binary Ninja

Fri, 17 Aug 2018 00:00:00 +0000

This blogpost is about the release of a plugin for Binary Ninja that allows you to run a Python Kernel inside the Binary Ninja GUI environment to which you can attach a Jupyer (QT) console, formerly known as IPython shell. The first section is about why this is useful, the second is about some issues I encountered and how to solve them, and the third contains everything you need to know to set it up.

Reversing and Patching .NET Binaries with Embedded References

Mon, 30 Apr 2018 00:00:00 +0000

Lately I’ve been analyzing a .NET binary that was quite interesting. It was a portable binary that shipped without any third-party dependencies. I started looking at the .NET assembly with ILSpy and noticed that there was not that much code that ILSpy found and there were a lot of references to classes/methods that were neither in the classes identified by ILSpy nor were they part of the .NET framework.

At some point I was going through everything that ILSpy displayed about the binary, including the resources which were looking very interesting:

Yet another edition of BlackHoodie – #BlackHoodie17

Mon, 11 Dec 2017 00:00:00 +0000

I am amazed by how this years BlackHoodie unraveled. Three days that included a pre-conference of lightening talks and two parallel tracks with a total of 64 enthusiastic members. The very spirit of BlackHoodie is nothing other than the quest to gain deep knowledge. Reverse engineering is one of the hardest fields in security. It touches on all fields of computing, starting from assembly, programming, file formats, operating systems, networks and what not. This makes it hard but an extremely fulfilling experience to spend time learning it. For me, the very idea of staring at a binary till you understand what it does is a magical feeling.

Autonomic Networking – Part 2: Analysis

Mon, 20 Mar 2017 00:00:00 +0000

This is the second part in the Autonomic Network series. We have introduced previously in our first part the Autonomic Network (AN), took a look about the needed configuration to run it on Cisco gear and what is the expected communication flow. In this post, we will dive deeper to have a closer look on the packets and how they are composed. Cisco’s AN protocol is a proprietary one and as far as I know, the analysis provided here for the protocol is the first of its kind.

Autonomic Networking – Part 1: Overview

Sun, 19 Mar 2017 00:00:00 +0000

This is a 3-part series which introduces and analyzes Cisco’s implementation for Autonomic Network. In the 1st part, the technology is introduced and we have an overview about communication flow. In the 2nd part, Cisco’s proprietary protocol is reverse engineered ? then finally in the 3rd part, multiple vulnerabilities will be disclosed for the first time. If you’re aware of the technology, you can skip directly to part 2 where the action begins!

BlackHoodie 2016

Mon, 21 Nov 2016 00:00:00 +0000

This year’s BlackHoodie workshop rolled out with 28 amazing women from all parts of the world. It was a very vibrant group with students, professionals, engineers, researchers, physicists and what not. This is the second year that Marion Marschalek is running this reverse engineering workshop exclusively for women. There were a variety of topics that were covered. This includes anti emulation tricks, anti debuggers, packers, obfuscation, encryption/decryption functions, and a lot of fun with IDA.

Reverse Engineering With Radare2 – Part 3

Mon, 24 Oct 2016 00:00:00 +0000

Sorry about the larger delay between the previous post and this one, but I was very busy the last weeks.
(And the technology I wanted to show wasn’t completely implemented in radare2, which means that I had to implement it on my own 😉 ). In case you’re new to this series, you’ll find the previous posts here.

As you may already know, we’ll deal with the third challenge today. The purpose for this one is to introduce
some constructs which are often used in real programs.

Reverse Engineering With Radare2 – Part 2

Mon, 29 Aug 2016 00:00:00 +0000

Welcome back to the radare2 reversing tutorials. If you’ve missed the previous parts, you can find them here and here.

Last time we’ve used the rabin2 application to view the strings found inside the challenge01 binary to find password candidates. Based on the results we looked into the assembly to find the correct password. In this post, we’ll go through the next challenge and try out some of the features provided by radare2.

Reverse Engineering With Radare2 – Part 1

Fri, 19 Aug 2016 00:00:00 +0000

Welcome back to the radare2 reversing tutorials. If you’ve missed the intro, you can find it here.

The last time you got the challenge01 binary and your goal was to find the password for the login. Let’s see how the application looks like:

$ ./challenge01
##################################
#          Challenge 1           #
#                                #
#      (c) 2016 Timo Schmid      #
##################################
Enter Password: test
Wrong!

The first and simplest step would be to look for strings inside the binary. We could do this either by using the unix utility strings or the binary analyzing binary from radare rabin2:

PFX Profiles in Microsoft’s System Management Server

Fri, 05 Aug 2016 00:00:00 +0000

In a recent assessment, we had to evaluate how Microsoft’s System Management Server (SMS) certificate management solution (CMS) stores and handles certificates. This question came up because sensitive, encrypted user certificates were to be stored in the SMS CMS. Due to the sensitivity of the handled certificates, we assessed the protection capabilities of the certificate management solution against extraction attempts from a local attacker with administrative privileges.

How did we do it?

We determined a five steps approach to gain access to the certificates and be able to decrypt the accessed certificate material:

Reverse Engineering With Radare2 – Intro

Wed, 03 Aug 2016 00:00:00 +0000

As some of you may know, there is a “new” reverse engineering toolkit out there which tries to compete with IDA Pro in terms of reverse engineering. I’m talking about radare2, a framework for reversing, patching, debugging and exploiting.

It has large scripting capabilities, runs on all major plattforms (Android, GNU/Linux, [Net|Free|Open]BSD, iOS, OSX, QNX, w32, w64, Solaris, Haiku, FirefoxOS and even on your pebble smartwatch 😉 ) and is free.

Discover the Unknown: Analyzing an IoT Device

Mon, 11 Apr 2016 00:00:00 +0000

This blog post will give a brief overview about how a simple IoT device can be assessed. It will show a basic methodology, what tools can be used for different tasks and how to solve problems that may arise during analyses. It is aimed at readers that are interested in how such a device can be assessed, those with general interest in reverse engineering or the ones who just want to see how to technically approach an unknown device.

unrubby: reversing without reversing

Fri, 01 Apr 2016 00:00:00 +0000

The talk “unrubby: reversing without reversing” was part of the Troopers conference in Heidelberg, 16 March 2016. The talk was done by Richo Healey, who is currently working on the security engineering team at the Irish payment company Stripe. Richo Healey is an experienced conference speaker. Amongst other he has spoken at Kiwicon, DEF CON and 44con.

In his talk Richo Healey spoke about reverse engineering of Ruby software. First he talked about existing tools and techniques to regenerate source code from Ruby bytecode. Then he presented a new concept, which is implemented in his tool “unrubby”.

Reverse Engineering a Digital Two-Way Radio

Thu, 31 Mar 2016 00:00:00 +0000

In their talk “Reverse Engineering a Digital Two Way Radio” Travis Goodspeed and Christiane Ruetten presented the challenges they faced and overcame while reverse engineering “Tytera MD380”, a handheld transceiver for the Digital Mobile Radio (DMR) protocol.

“Tytera MD380” is based around two chips: STM32F405 CPU with an ARM Cortex M4F core and Readout Device Protection and a HRC5000 baseband processor which implements the actual digital radio. While STM32F405 is fully documented, there is no documentation for HRC5000 publicly available but with the help of the Chinese community they were able to obtain the Chinese documentation.

SDR and non-SDR tools for reverse engineering wireless systems

Mon, 28 Mar 2016 00:00:00 +0000

Hey there!
The God of frequencies Michael Ossmann visited us again this year at the TROOPERS16 and showed us how to break another device using a specific setup.

Last time he introduced the HackRF One to us (Read here:https://www.insinuator.net/2014/08/hackrf-one-the-story-continues/), but this post is a short summary of his talk about “Rapid Radio Reversing”, he is a wireless security researcher, who makes hardware for hackers. Best known for the HackRF, Ubertooth, and Daisho projects, he founded Great Scott Gadgets in an effort to put exciting, new tools into the hands of innovative people.

How to crack a white-box without much effort

Wed, 02 Mar 2016 00:00:00 +0000

By: Philippe Teuwen (@doegox)

White-box cryptography is a relatively new field that aims at enabling safely cryptographic operations in hostile situations.
A typical example is its use in digital-right management (DRM) schemes, but nowadays you also find white-box implementations in mobile applications such as Host Card Emulation (HCE) and the protection of credentials to the cloud.
In all these use-cases the software implementation uses the secret key of a third-party which should remain secret from the owner of the device which is running this executable.

Dynamic IDA Enrichment (aka. DIE)

Thu, 28 Jan 2016 00:00:00 +0000

Last year on the Hex-rays plugin Contest the Dynamic IDA Enrichment (DIE) plugin won first place, so we decided to have a look and play around with it.

DIE extends IDA to add Dynamic Data to the static analysis. So after the installation, we are able to perform the static analysis using a lot of supporting information from the actual execution of the binary under assessment.

Since DIE is purely written in Python you will need at least Python 2.7 and IDA Versions prior to 6.8 won´t work. In the current version DIE will only work on Windows which will hopefully soon be available cross-platform.

BlackHoodie: Reversing Workshop for Women

Tue, 29 Sep 2015 00:00:00 +0000

In the beginning of September, I had an opportunity to take part in BlackHoodie – a reversing workshop for women organized by Marion Marschalek, senior malware researcher at Cyphort, Inc. It took place on 5th and 6th of September at University of Applied Sciences St. Pölten, Austria.

Besides me, 14 more young women from different countries came to attend the workshop; the overall atmosphere was very friendly and productive. Before the actual event all participants were getting preparatory assignments and recommendations (not to spend our two days on learning the very basics), and during the workshop itself we got our hands on analyzing and reversing some actual malware samples. I personally found it very interesting how one can detect and overcome several layers of anti-analysis protection. I left the workshop excited and packed with some new knowledge as a basis for further skills development – it’s just the beginning! 😉

How to Own a Router – Fritz!Box AVM Vulnerability Analysis

Tue, 11 Mar 2014 00:00:00 +0000

The below post was originally written on February 9th as a little educational exercise & follow-up to my BinDiff post. (This research was actually triggered by a relative asking about that strange Fritz!Box vulnerability he heard about on the radio). Once we realized the full potential of the bug we decided against publishing the post and contacted several parties instead. Amongst others this contributed to the German BSI press release. Given the cat is out of the bag now anyway, we see no reason to hold it back. We will further take this as an opportunity to lay out our basic vulnerability disclosure principles in a future post. This topic will also be discussed in the panel “Ethics of Security Work & Research” at Troopers

Bluevoxing

Thu, 21 Feb 2013 00:00:00 +0000

This is a guest post from Graeme Neilson

Reverse engineering is generally thought of as using debuggers, disassemblers and hex editors. Much as I love hex editors, IDA and staring at opcodes for the last few years I have been focused on applying my reverse engineering methodology to larger, composed systems. At Troopers TelcoSec day this year I will be presenting Bluevoxing which demonstrates how this approach works. Bluevoxing is about reverse engineering how web based “audio one time password” systems work. Simply put audio one time password systems use a short audio file as an authentication token. When I discovered these systems I was intrigued as reversing them would involve a range of techniques and tools from web testing, audio tools, signal analysis, phreaking and cryptanalysis. The disassembler would be of no use instead I would have to employ audio tools such as audacity and ruby-processing.