During our malware analysis, we often come across samples that contain (custom) hashes in stead of cleartext. Hashing is done in an effort to bypass detection and hinder malware analysts. There are tools to recover cleartext from known hashing methods (like John the Ripper and hashcat). But for custom hashing methods, you'll have to write … Continue reading Recovering custom hashes for the Petya/Notpetya malware
On June 27, 2017, we were informed via several channels that attackers launched a new type of ransomware. This cyber-attack affects companies across Europe and the US. The attack has some similarities with a previous attack known as “Wannacry”, but it has some distinct features. The advisory below has been sent out to all our … Continue reading To Petya or not to Petya
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 … Continue reading A word from our interns Aras, Gaetan and Wouter!
A new type of malicious MS Office document has appeared: a PowerPoint document that executes a PowerShell command by hovering over a link with the mouse cursor (this attack does not involve VBA macros). In this blogpost, we will show how to analyze such documents with free, open-source tools. As usual in attacks involving malicious … Continue reading Malicious PowerPoint Documents Abusing Mouse Over Actions