Releasing logalert.py – Smart piping of command output to email for alerting

Introduction Today we are releasing a small but useful tool, logalert.py. This tool can be used to pipe standard output to email for the purpose of alerting. A simple caching system is used to avoid sending duplicate alerts within a certain timeframe. The tool was developed for cases where you want a simple and robust …

Video: Attack Surface Reduction (ASR) Bypass using VBA

Introduction Attack surface reduction rules in Windows target software behaviors that are often abused by attackers. In this blog post & video, we want to demonstrate a way of bypassing one of these rules from within VBA. Bypass Parent process selection can be done from VBA. There is an Attack Surface Reduction rule to block …

To Zoom or Not to Zoom

During these COVID-19 times, personal interaction with colleagues and customers is no longer straightforward. Lots of companies are therefore looking into video conferencing solutions. One of the most popular out there, Zoom, recently hit the news with multiple security and privacy issues. Although this definitely needed to be fixed by Zoom (a first update addressing …

Report sightings from Kibana to MISP

Introduction A problem we all face when using threat intelligence data is getting rid of false positives in our data feeds. On the other hand, reporting of true positives is equally important as it allows to increase the level of trust in an indicator. This post describes how you can report false and true positives …

Working from home: tell staff about phishing & data leakage [template e-mails included]

Source: gcn.com It comes as no surprize to us, as security professionals, that hackers have been exploiting the COVID-19 situation in a series of Corona-themed scams - take this recent message from Interpol, for example. With the progressive (or not) implementation of lock down-like restrictions across the world, companies are turning to remote working to …

Windows Hardening in the cloud with Azure Automation

In a previous blogpost, we discussed the OS hardening baselines for Windows Server 2016 written in PowerShell DSC, which we made publicly available on the NVISO GitHub page. Using this, you can define your own hardening baseline to use within your own environment. Once a baseline is defined, we want to apply it to the …

Windows Server Hardening with PowerShell DSC

Operating system hardening is the process of improving the security of a default OS installation to minimize the attack surface that can be exploited by an attacker. But doing this manually on each system that is deployed on-premise or in the cloud is a cumbersome task. It can lead to inconsistent security configurations because of …

Evidence of VBA Purging Found in Malicious Documents

TL;DR We have found malicious Office documents containing VBA source code only, and no compiled code. Documents like these are more likely to evade anti-virus detection due to a technique we dubbed "VBA Purging". VBA Purging techniqueMalicious MS Office documents leveraging VBA, have their VBA code stored inside streams of Compound File Binary Format files. …

IoT hacking field notes #1: Intro to glitching attacks

TL;DR: First in a new series of short, IoT-related posts, this tells the story of a simple glitching attack we used to get a bootloader shell and ultimately root a device. IoT field notes is a new series of short stories about interesting (hopefully πŸ™‚ ) observations, vulnerabilities and techniques, inspired directly from the IoT …

My journey reaching #1 on Hack The Box Belgium – 10 tips, tricks and lessons learned.

Ranked #1 on HackTheBox Belgium Not so long ago, I achieved a milestone in my penetration testing career.: reaching rank 1 on HackTheBox. For those of you that don't know what Hack The Box (HTB) is: Hack The Box is an online platform allowing you to test your penetration testing skills and exchange ideas and …