Hunting Emotet campaigns with Kusto

Introduction Emotet doesn't need an introduction anymore - it is one of the more prolific cybercriminal gangs and has been around for many years. In January 2021, a disruption effort took place via Europol and other law enforcement authorities to take Emotet down for good. [1] Indeed, there was a significant decrease in Emotet malicious … Continue reading Hunting Emotet campaigns with Kusto

Kernel Karnage – Part 7 (Out of the Lab and Back to Reality)

This week I emerge from the lab and put on a different hat. 1. Switching hats With Interceptor being successful in blinding $vendor2 sufficiently to run a meterpreter reverse shell, it is time to put on the red team hat and get out of the perfect lab environment. To do just that, I had to … Continue reading Kernel Karnage – Part 7 (Out of the Lab and Back to Reality)

Kernel Karnage – Part 6 (Last Call)

With the release of this blogpost, we’re past the halfway point of my internship; time flies when you’re having fun. 1. Introduction - Status Report In the course of these 6 weeks, I’ve covered several aspects of kernel drivers and EDR/AVs kernel mechanisms. I started off strong by examining kernel callbacks and why EDR/AV products … Continue reading Kernel Karnage – Part 6 (Last Call)

New mobile malware family now also targets Belgian financial apps

While banking trojans have been around for a very long time now, we have never seen a mobile malware family attack the applications of Belgian financial institutions. Until today... Earlier this week, the Italy-based Cleafy published an article about a new android malware family which they dubbed TeaBot. The sample we will take a look … Continue reading New mobile malware family now also targets Belgian financial apps

How to analyze mobile malware: a Cabassous/FluBot Case study

This blogpost explains all the steps I took while analyzing the Cabassous/FluBot malware. I wrote this while analyzing the sample and I've written down both successful and failed attempts at moving forward, as well as my thoughts/options along the way. As a result, this blogpost is not a writeup of the Cabassous/FluBot malware, but rather … Continue reading How to analyze mobile malware: a Cabassous/FluBot Case study

Epic Manchego – atypical maldoc delivery brings flurry of infostealers

In July 2020, NVISO detected a set of malicious Excel documents, also known as “maldocs”, that deliver malware through VBA-activated spreadsheets. While the malicious VBA code and the dropped payloads were something we had seen before, it was the specific way in which the Excel documents themselves were created that caught our attention. The creators … Continue reading Epic Manchego – atypical maldoc delivery brings flurry of infostealers

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. … Continue reading Evidence of VBA Purging Found in Malicious Documents

Analyzing a Malicious Spreadsheet Dropping a DLL

Introduction This week, we received a suspicious spreadsheet which was used as a malware dropper in a phishing campaign. The spreadsheet writes a DLL file to disk and subsequently executes it. In this blog post, we perform the full analysis of the suspicious spreadsheet. Analyzing the document The analysis of this Excel file starts with … Continue reading Analyzing a Malicious Spreadsheet Dropping a DLL

Malicious SYLK Files with MS Excel 4.0 Macros

Since about a week, we are seeing an increase of SYLK files submitted to VirusTotal. A SYLK file (SYmbolic LinK) is a pure text file format used to store Excel spreadsheets with extension .slk. Although SYLK files can't contain VBA macros, they can still contain executable code, for example DDE commands or MS Excel 4.0 … Continue reading Malicious SYLK Files with MS Excel 4.0 Macros