Category Archives: nviso


Staying up to date with the latest hot topics in Security is a requirement for any Security Consultant. Going to conferences is a great way of doing this, as it also gives you the opportunity to speak to peers and get a good view into what the security industry and the researchers are up to.

This year, we sent a small delegation to DEF CON, which is one of the most known Security Conferences in the world. We think everyone should go there at least once in their careers, so this year we sent Michiel, Cédric, Jonas and Jeroen to get their geek-on in Las Vegas!

From left to right: Cédric, Michiel, Jonas and Jeroen ready for their first DEF CON!
Ready to turn off your phones and laptops…

The conference was held at Caesar’s Palace’s conference center, right in the middle of the famous strip. There were four parallel tracks for talks and a lot of different villages and demos throughout the entire conference. We know that What happens in Vegas, Stays in Vegas, but some of these talks were just too good not to share!

Internet of Things (IoT)

There was a large focus on IoT this year, which was great news for us, as we’re actively evolving our IoT skillset. Cédric, our resident IoT wizard, has been running around from talk to talk.

A further update on the IoT track will be provided by Cédric once he is back from holidays 🙂


The amount of talks on Android / iOS was fairly limited, but there were definitely some talks that stood out. Bashan Avi gave a talk on Android Packers. The presentation is very thorough and tells the story of how they used a few of the most popular packers to devise an algorithm for detecting and unpacking variations of the same concept. Their approach is very well explained and could be really interesting for our own APKScan service.

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A typical flow of Android Packers (source)

On Sunday, Stephan Huber and Siegfried Rasthofer presented a talk on their evaluation of 9 popular password managers for Android. Their goal was to extract as much sensitive information as possible on a non-rooted device. Even though you would expect password managers to put some effort into securing their application, it turns out this is rarely the case. The following slide gives a good overview of their results, but be sure to check out the entire paper for more information.

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The results of Stephan Huber and Siegfried Rasthofer’s research on Android Password Managers (source)


One of the most interesting talks for us was given by John Sotos (MD). While almost all talks focus on very technical subjects, John gave an introduction on the Cancer Moonshot Project and how creating a gene-altering virus targeted at specific DNA traits is inevitable. This is of course great from a Cancer-treatment point of view, but what if someone would alter the virus to attack different genes? Maybe an extremist vegetarian could make the entire world allergic to meat, or maybe a specific race could be made infertile… In his talk, John explains what could go wrong (and he is very creative!) and how important it is to find a defense against these kinds of viruses even before they actually exist.


Crypto Village

One of our biggest projects within NVISO Labs consists out of building an out-of-band network monitoring device. In the most recent years we’ve seen a lot of the web shift to HTTPS.


While this is definitely a good thing in terms of security, it does limit the possibilities of monitoring network traffic. Malware authors know this as well, and are starting to increasingly adopt TLS/HTTPS in their CnC communications (e.g. the Dridex family). In the crypto village, Lee Brotherston demonstrated various techniques to fingerprint TLS connections and even showed a working PoC. This could allow us to create fingerprints for various malware communications and detect them on the network. More information can be found on Lee’s GitHub page.

Car Hacking Village

When we were looking through the villages available at DEF CON this year, the newest car hacking village immediately caught our attention. In the room were several cars with laptops hooked to the dashboards and people trying to completely take over the controls. In the middle of the room was a brand new Dodge Viper of which the steering controls got reprogrammed to control a video game instead of the actual car. Some of our colleagues even got the chance to test drive it! Although with mixed results …


Jonas learning how to drive a sports car (and not doing a great job 😜).

Packet Hacking Village

The Packet Hacking Village (PHV) is one of the biggest, if not the biggest, village in DEF CON. It’s also the place where Jonas spent a lot of his time, meticulously following talks and taking notes. Different talks could be linked to various steps of the cyber kill chain and were interesting to consider for red teaming assessments or as part of the blue team protecting against these attacks.

One of the presentations that stilled our offensive hunger was given by Gabriel Ryan and discussed wireless post-exploitation techniques. One of the attacks allows to steal AD credentials through a wireless attack using a ‘hostile portal’ that redirects a victim’s HTTP traffic to SMB on the attacker’s machine. This, and his other attacks were facilitated by his own eaphammer tool.

Our blue side was satisfied as well with a talk on Fooling the Hound, which attempts to thwart attackers making use of the BloodHound tool, aimed at visualizing the relationships within an AD environment. His deceptions include fake high-privilege credentials, which increase the shortest path towards a high-value asset. The resulting BloodHound graph showed a greatly increased number of nodes and edges, thereby complicating an attacker’s lateral movements!

Meetup with the CSCBE winners

As you may know, the winners of NVISO’s Cyber Security Challenge 2017 received tickets to DEF CON which was an excellent opportunity to have a little Vegas CSC reunion!


Return to sender

All good things come to and end, and so did the DEF CON conference. We had a really great time in Las Vegas, and everyone made it home safely without losing too much money at the poker table ;-).

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Who is watching your home surveillance systems?

This morning, I heard on the radio that dozens of Belgian families were being watched through their own home surveillance system in Belgium. Nothing new here, as we already know for years that sites exist through which you can watch camera footage of unknowing victims, and this problem is not just limited to Belgium of course.

Now, looking at this from an IT security perspective, it would be easy to say “it’s their own fault, they should have changed their default passwords!” or “it’s their own fault, why would you make your surveillance system internet accessible?”. The reality is that most users don’t see an issue with connecting their home surveillance system to the internet – especially not if it’s fully supported by the vendor! In the end, it’s reasonable for the user to expect from the vendor that the surveillance system is installed in a secure way.


A quick search on Shodan – a search engine for connected devices – shows thousands of publicly exposed surveillance systems all over the world.

A few weeks ago, one of our colleagues had a specialized firm install security cameras around the house. Our colleague had to move heaven and earth to explain that the video controller should not be directly connected to the internet but that it should be connected to the internal network which is firewalled. As you can see, most people would have no notion of this and would be happy to see the video footage everywhere they go from an app on their smartphone without any type of authentication.

Now, how to avoid your home surveillance system from being viewed by anyone in the world? Well there are several things you can do here, varying in terms of technical difficulty (non-exhaustive list).

  1. Password-protect all your connected devices, and remove anonymous access.
  2. Change the default password on all your connected devices. This will prevent that these devices can be accessed by anyone on the internet using default credentials, such as username and password both being “admin” or “demo”.
  3. Keep your camera software up to date. As with all electronic devices running software is the case, camera systems could contain bugs that allow unauthorized individuals to take control of and view your images. When bugs in cameras are identified, usually (unfortunately not always), the vendors release patches to fix these bugs.
  4. Connect wireless cameras to a secured wireless network. If you use wireless cameras, it is important to connect them to a secure (WPA2) wireless network. This will prevent anyone in the vicinity of your network to eavesdrop on and intercept the communication.

Last but not least, more and more vendors are allowing end users to connect their devices to the cloud and have them view the images through a secured online portal. Moving forward this looks to be a good solution for private homes as with this solution it is not needed to make your cameras internet accessible but in the same time you would be able to view your live feeds from anywhere. In this case, the security of the solution also depends on the security of the vendor cloud environment.

We are currently performing research on the security of home surveillance systems and will post updates on this soon, so stay tuned!

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Our team is researching common security errors in IoT devices as we speak

A word from our interns Aras, Gaetan and Wouter!

During the first half of 2017 we had the pleasure of working with three bright interns assisting us on various projects ranging from developing an interactive training platform to creating challenges for the Cyber Security Challenge to working on improving our own IT environment.

We asked them to let us know what they thought of their time spent here. Below is the feedback we received!


Posing in front of our beloved blue bird with a great smile! 😊

During my internship at NVISO, I assisted the company into deploying and assessing new components in the IT environment. Due to NVISO’s sector of operation, a large emphasis was placed on the security of this environment both in the cloud and on the workstations used to access the services and resources. The aim of this migration was to provide a more unified set of services with increased productivity features while maintaining a strong, secure and controlled environment.

Overall it was a pleasure to work at NVISO during my internship. Working with such a dynamic team was a pleasure, and the overall ambiance and working with like-minded people was a delight.

Personally I am proud on doing my internship at NVISO and also with his team that had respect, experience and fun.
During my internship I did two different projects:
1 – creation of the IoT village for the Cyber Security Challenge
2 – Working with open source information databases on connected devices, such as Shodan.

Thank you again guys to all great moment and your patience,

Wouter – Howest:
During my internship I worked on building the back end for an interactive training infrastructure. This infrastructure will help NVISO in improving its trainings, demonstrations and workshops. Building this infrastructure would not have been possible without the support of the NVISO team. I really enjoyed working at NVISO during my internship. The working atmosphere and colleagues are really top notch.

We would like to take this opportunity to thank you all for your commitment and enthusiasm you all brought into the workplace! Hope to see you again soon 🐀!

The entire NVISO team.

MoveBot: Battling inactivity one micro-exercise at a time

Many of our NVISO colleagues are very active during their free time. We have colleagues who go mountain-biking, rock climbing, swimming, running, … The problem is that during the day, they often sit at their desk for four hours straight, grab some lunch, and go back to their desk to sit and work at their computers. To make everyone just a little bit more active during the day, we created MoveBot.

MoveBot is a Slack bot that posts messages to our Slack channel twice a day. For example, just this morning, I got the following notification:

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After having done the exercise, I clicked the “I did it” button, and MoveBot congratulated me:

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Of course, a concept like this doesn’t work without some gamification, so every time someone completes an exercise, they get some points. At the end of the month, we give out a little prize to the most active members. You may think that this encourages cheating, but that’s why we had everyone sign a mock contract where they promise to try to live healthy and never ever ever lie to MoveBot ;).

We also use our MoveBot to do some team-building. For example, our set of “exercises” also includes “go get lunch for a colleague” or “during lunch, take a walk around the block with a colleague”.

Sharing is caring, so we’ve pushed the basic code behind our MoveBot to GitHub. Keep in mind that this was a quick project (and my first ever Flask/SQLAlchemy application) so the code isn’t that great, but it does what it’s supposed to do :).


Using to detect files touched by malware

Yesterday, we released – a tool you can use to detect unwanted changes to the file sytem. The tool and documentation is available here:

Binsnitch can be used to detect silent (unwanted) changes to files on your system. It will scan a given directory recursively for files and keep track of any changes it detects, based on the SHA256 hash of the file. You have the option to either track executable files (based on a static list available in the source code), or all files. can be used for a variety of use cases, including:

  • Use to create a baseline of trusted files for a workstation (golden image) and use it again later on to automatically generate a list of all modifications made to that system (for example caused by rogue executables installed by users, or dropped malware files). The baseline could also be used for other detection purposes later on (e.g., in a whitelist);
  • Use to automatically generate hashes of executables (or all files if you are feeling adventurous) in a certain directory (and its subdirectories);
  • Use during live malware analysis to carefully track which files are touched by malware (this is the topic of this blog post).

In this blog post, we will use during the analysis of a malware sample (VirusTotal link:

A summary of options available at the time of writing in

usage: [-h] [-v] [-s] [-a] [-n] [-b] [-w] dir

positional arguments:
  dir               the directory to monitor

optional arguments:
  -h, --help        show this help message and exit
  -v, --verbose     increase output verbosity
  -s, --singlepass  do a single pass over all files
  -a, --all         keep track of all files, not only executables
  -n, --new         alert on new files too, not only on modified files
  -b, --baseline    do not generate alerts (useful to create baseline)
  -w, --wipe        start with a clean db.json and alerts.log file

We are going to use to detect which files are created or modified by the sample. We start our analysis by creating a “baseline” of all the executable files in the system. We will then execute the malware and run again to detect changes to disk.

Creating the baseline


Command to create the baseline of our entire system.

We only need a single pass of the file system to generate the clean baseline of our system (using the “-s” option). In addition, we are not interested in generating any alerts yet (again: we are merely generating a baseline here!), hence the “-b” option (baseline). Finally, we run with the “-w” argument to start with a clean database file.

After launching the command, will start hashing all the executable files it discovers, and write the results to a folder called binsnitch_data. This can take a while, especially if you scan an entire drive (“C:/” in this case).


Baseline creation in progress … time to fetch some cheese in the meantime! 🐀 🧀

After the command has completed, we check the alerts file in “binsnitch_data/alerts.log”. As we ran with the “-b” command to generate a baseline, we don’t expect to see alerts:

Capture 2.PNG

Baseline successfully created! No alerts in the file, as we expected.

Looks good! The baseline was created in 7 minutes.

We are now ready to launch our malware and let it do its thing (of-course, we do this step in a fully isolated sandbox environment).

Running the malware sample and analyzing changes

Next, we run the malware sample. After that, we canrun again to check which executable files have been created (or modified):


Scanning our system again to detect changes to disk performed by the sample.

We again use the “-s” flag to do a single pass of all executable files on the “C:/” drive. In addition, we also provide the “-n” flag: this ensures we are not only alerted on modified executable files, but also on new files that might have been created since the creation of the baseline. Don’t run using the “-w” flag this time, as this would wipe the baseline results. Optionally, you could also add the “-a” flag, which would track ALL files (not only executable files). If you do so, make sure your baseline is also created using the “-a” flag (otherwise, you will be facing a ton of alerts in the next step!).

Running the command above will again take a few minutes (in our example, it took 2 minutes to rescan the entire “C:/” drive for changes). The resulting alerts file (“binsnitch_data/alerts.log”) looks as following:


Bingo! We can clearly spot suspicious behaviour now observing the alerts.log file. 🔥

A few observations based on the above:

  • The malware file itself was detected in “C:/malware”. This is normal of-course, since the malware file itself was not present in our baseline! However, we had to copy it in order to run it;
  • A bunch of new files are detected in the “C:/Program Files(x86)/” folder;
  • More suspicious though are the new executable files created in “C:/Users/admin/AppData/Local/Temp” and the startup folder.

The SHA256 hash of the newly created startup item is readily available in the alerts.log file: 8b030f151c855e24748a08c234cfd518d2bae6ac6075b544d775f93c4c0af2f3

Doing a quick VirusTotal search for this hash results in a clear “hit” confirming our suspicion that this sample is malicious (see below). The filename on VirusTotal also matches the filename of the executable created in the C:/Users/admin/AppData/Local/Temp folder (“A Bastard’s Tale.exe”).

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VirusTotal confirms that the dropped file is malicious.

You can also dive deeper into the details of the scan by opening “binsnitch_data/data.json” (warning, this file can grow huge over time, especially when using the “-a” option!):


Details on the scanned files. In case a file is modified over time, the different hashes per file will be tracked here, too.

From here on, you would continue your investigation into the behaviour of the sample (network, services, memory, etc.) but this is outside the scope of this blog post.

We hope you find useful during your own investigations and let us know on github if you have any suggestions for improvements, or if you want to contribute yourself!

Squeak out! 🐁


NVISO at Hack Belgium

Last week, a few of us attended the first edition of Hack Belgium. Describing what Hack Belgium is turns out to be a bit difficult: is it a conference? A hackaton? A hands-on workshop? A technology fair? A pitch? In my view, it’s all of those combined – and that made the event so interesting!

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9AM – Daan, Jeroen, Kris & Kurt looking sharp at Hack Belgium ( … and ready for some ☕️!).

Hack Belgium offers its attendees 14 crucial challenges around topics that keep our world busy: from healthcare to mobility and building intelligent cities. Over the course of 3 days, all attendees put their heads together to come up with a bright solution to these challenges. With the help of more than 300 experts, it’s certainly a great experience and exercise in idea generation! The objective is to pitch your idea on Saturday and to walk out of Hack Belgium with a blueprint to start working on your project.

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Our CEO Kurt ready to escape reality 🕶.

OK, I have to confess – we did not stay until Saturday for our pitch, however we did have a lot of fun and interesting moments on Thursday and Friday! We worked on a concept for the media to bring news in a more balanced format, we did a workshop on designing connected projects, we attended an expert session on the state of Virtual Reality (VR) and Augmented Reality (AR), and we had fun playing around with IBM Watson and other upcoming technologies.


Kris showing off his drawing skills 🐁.

Pulling off this type of event at this scale takes a lot of preparation (and guts!) – we want to congratulate  the Hack Belgium staff and all the volunteers involved! You truly made this into an interesting & worthwhile event.

We hope to be present for Hack Belgium 2018 and beyond (… and we will stay for the pitch, promise 🐀!).

A few more impressions after the break!


Proud to say we didn’t lose any fingers playing around with these beasts! 🖐


Beep Boop Beep Boop

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Playing around with creative ways to design connected products during a workshop. My drawing skills are inferior to the one from Kris, so no close-up 😃!

Let’s get the team together…

It was the last week of April: our entire NVISO team had packed their bags and was ready to board a plane. Where to? A secret location, to celebrate the achievements of our fantastic team !

Did all of you lab rats bring your passports? 🐀

Did all of you lab rats bring your passports? 🐀

Destination: unknown…
From the very beginning, it became clear that the discovery of our destination was a fun team-building event by itself: to find out, we’d have to solve a series of technical challenges eventually lifting the veil on that well-kept secret… right before getting our boarding passes !

In the morning, we were all supposed to meet up at our office. At exactly 9AM, we received a mail from HR containing a URL. The website was created using Drupal and contained a bit of teaser information concerning the offsite. It also had a login form, but we were lacking valid credentials. After some fiddling around and some scanning, we found it was vulnerable to Drupageddon. This allowed us to create a user account using SQL injection. Once logged into the website, we could create posts ourselves. This vulnerability also allowed us to run commands through PHP, but we weren’t able to simply launch a reverse shell. Using a Netcat pipe, we did succeed in getting shell access to the server. The next step was to look for some kind of flag. Some grepping and finding showed us the location of the flag, in a file containing instructions for the next piece of the puzzle.

Maybe we should have brought two computers into office this morning...

Maybe we should have brought two computers into office this morning…

From there on, we were split up in two teams. Team A would remain in Brussels and team B was set off to a gas station near the highway in Breda, in The Netherlands. There, Team B was to find “Lou”. Upon arrival at the gas station, team B inquired for Lou: the lady behind the counter looked at them as if they were about to pull a gun. Looking all over the gas station, Team B eventually identified Lou: the challenge could continue. But what should Team B tell Lou ?

Team A had to assist them: very soon, they found a USB key taped to one of the GoPro action cameras left behind by the organizers to record our endeavors. Forensic analysis was on! After booting kali, performing some volatility magic, deciding it took too long and running strings on the dump file, Team A discovered the passphrase that should be given to Lou at the gas station.

Once Team B provided the correct passphrase to Lou, he gave the next set of instructions for both Team A and Team B. Through an image puzzle, Team B found out they had to carry on towards Schiphol, the Amsterdam Airport. Lou would be there, somewhere, ready to hand out the next hint. Meanwhile, Team A were told they should find an envelope at the office. After flipping over all the tables, the envelope was found : it contained yet another USB key. This time, the USB key contained an encrypted zip file with a PCAP file inside. After putting its youngest new recruit in front of the computer in true Swordfish-first-scene style, Team A cracked the password and started analysis of the PCAP file. Captured traffic in the PCAP consisted of web browsing traffic towards the website of Brussels International Airport: the hint was clear, Team A rushed to the airport !

The destination? Dubai!

Our precious bird, watching over the Burj...

Our precious bird, watching over the Burj…

Our time in the City of Endless Possibilities
Taking some time to reflect is important. Taking some space (literally) helps to step back and look at the bigger picture. While we did reflect on where we had come from, our eyes were decidedly focused on the future. We spent quite some time discussing what we stand for as individuals and as a team: we discussed which values we want to share and live by, and how these values can make NVISO better, both for us and for our clients. The conversation resulted in valuable insights. Putting words on what we believe in, together, made everyone feel committed to upholding them, because they are what we believe in, and represent us best.

To then put our money where our mouth was, the rest of our time was invested in taking concrete actions: we set off to select one initiative that would help NVISO improve in practice. Four teams together proposed 8 ideas, which were challenged and judged by a ‘shark tank’, our very own jury.


The proposal attracting the most support was an initiative on internal sharing of knowledge between colleagues. So in the coming months, we will be working to build a framework that supports and promotes informal sharing of experiences and skills within NVISO. Because sharing is caring!

The winners of the Shark Tank 2017 - congratulations Hans, Benoit, Mercedes, Nico and Jeroen!

The winners of the Shark Tank 2017 – congratulations Hans, Benoit, Mercedes, Nico and Jeroen!

But let’s not fool ourselves: the trip was not all hard work. We also found time to enjoy the local attractions of Dubai and have lots of team fun. Loyal to the good old “work hard, play hard” motto, and believing in laughter as a great way to bond with colleagues, we rushed down crazy water slides in Aquaventure, chilled at the local beach and were inspired to aim higher at Burj Khalifa. In short, we made the most of our time there, enjoying some well-deserved rest, having fun and getting to know each other better as a great team. After all, we don’t travel to the City of Endless Possibilities every week!

Aarg ... we should have taken this picture before sunset! 🐀 😁

Aarg … we should have taken this picture before sunset! 🐀 😁