Companies tend to create their security detections based on the trending behavior of threat actors. One of the constantly re-occurring techniques is DNS-based activities like exfiltration via DNS (Domain Name System) or C2 (Command and Control) communication via DNS. Still, a lot of companies are …

Windows Subsystem for Linux (or, as I’m incorrectly calling it, Linux Subsystem for Windows) is a tool in Windows 10 that provides a Linux kernel on top of the Windows kernel. WSL can translate Linux system calls to Windows language. This way one can execute Linux-related apps/commands in …

This year an unofficial Defcon DFIR CTF was provided by Champlain College’s Digital Forensic Association. They created challenges in 5 topics which are available for anyone for a little practice on this site: defcon2019.ctfd.io. The challenges are sorted into the following categories: DFA Crypto …

Having information about USB devices connected to a system can be essential for some investigations and analyses. Most of the removable storages used nowadays are USB pen drives so knowing how to identify and investigate these is crucial. The main purpose of USB drive forensic analysis is to …

I have recently started to make some basic research with osquery. I investigated some malware infections in the past and I decided that I’m going to take a look at them with osquery as well. I was curious how much data I can retrieve with osquery and how much I will benefit from its usage. I …

Recently, a friend of mine has asked for my help in an investigation. In his SIEM system, he saw that a machine generated some DNS sinkhole events, but he couldn’t find the originally requested DNS by the host. The events were generated because the machine tried to resolve a DNS hostname which …

During my File System Tunneling related investigation I tested NTFS timestamp changes in case of different operations on Windows 10. I used SANS’s DFPS_FOR500_v4.9_4-19 and Cyberforensicator’s timestamp posters for comparison. I found out that my results were different from theirs. In my …

File System Tunneling is a really old feature of Windows. It was already discussed on many security or Windows administration related blogs and books. However, it is still somewhat obscure for lots of examiners because its forensic implication is limited. The simplest way to test and observe it in …

There are various different methods and techniques to evade detection by an IDS. If you know how a SIEM in a network works you can also adapt your attack to prevent the target from detecting your move. But this post is a first of a series in which I want to share my (only) 3 years of observation and …