Windows – Insinuator.net

July 15, 2025 by Tillmann Oßwald

Windows Hello for Business – The Face Swap

In the last blog post, we discussed the full authentication flow using Windows Hello for Business (WHfB) with face recognition to authenticate against an Active Directory with Kerberos and showcased existing and new vulnerabilities. In this blog post, we dive into the architectural challenges WHfB faces and explore how we can exploit them.

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Misc

June 20, 2025 by Tillmann Oßwald

Windows Hello for Business – Past and Present Attacks

Windows Hello for Business is a key component of Microsoft’s passwordless authentication strategy. It enables user authentication not only during system sign-in but also in conjunction with new and advanced features such as Personal Data Encryption, Administrator Protection, and Recall. Rather than depending on traditional passwords, Windows Hello leverages a PIN or biometric methods – such as fingerprint or facial recognition – to unlock cryptographic keys protected by the Trusted Platform Module (TPM).

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Misc

January 29, 2025 by Justus Hoffmann

Jigsaw RDPuzzle: Piecing Attacker Actions Together

In a recent incident response project, we had the chance to virtually look over the attackers’ shoulder and observe their activities. The attackers used the Remote Desktop Protocol (RDP) for lateral movement within the compromized environment and beyond (MITRE techniques T1570, T1021). As a matter of fact, RDP creates cache files that contain tiles of the transferred screen recording data. While this fact is well-known and there are existing tools, we found it worth reporting because of two different aspects:

On the one hand, we want to raise awareness for this valuable piece of evidence, explain how it works, how tooling works and how it can be used. In this particular case, the analysis of those cache files yielded valuable insights into the attackers’ activity and allowed further measures.
On the other hand, we found it exciting to look over the attacker’s shoulder, see the desktop as they saw it, and the commands they typed. We want to share parts of those insights as far as we are able to show them publicly.

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Misc

August 20, 2024 by Baptiste David

CrowdStrike: What is the worldwide BSOD all about?

This article is about the massive BSOD triggered by CrowdStrike worldwide on July 19. Analysis and information from CrowdStrike or other sources are regularly published, completing what is expressed here. Updates may also be provided in the future.

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Misc

April 16, 2024 by Tillmann Oßwald

BSI Publishes Windows 10 SiSyPHuS Reports: Application Compatibility Infrastructure, Microsoft Defender Antivirus ETW Usage and Device Setup Manager Service

The German Federal Office for Information Security (BSI – Bundesamt für Sicherheit in der Informationstechnik) has published several papers ERNW created as part of the long-term SiSyPHuS Win10-Project. This project focuses on system analysis of selected parts of the Windows 10 operating system performed by ERNW.

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Building

December 31, 2021 by Frank Block

Release of PTE Analysis plugins for Volatility 3

I’m happy to announce the release of several plugins for Volatility 3 that allow you to dig deeper into the memory analysis. One of those plugins is PteMalfind, which is essentially an improved version of malfind. Another one is PteResolve which, similarly to the WinDBG command !pte, allows you to inspect Page Table Entry (PTE) information for e.g., a given virtual address. In this blog post we will have a closer look at these and more plugins, and the PteEnumerator base class and what you can do with it. The memory dump used for this blog post is available here. Some of the injection tools used in this blog post can be gathered from here.

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Misc

November 17, 2020 by Aleksandar Milenkoski

Microsoft Office Telemetry: Report Release

The German Federal Office for Information Security (orig., ger., Bundesamt für Sicherheit in der Informationstechnik – BSI) has published our report on Microsoft Office Telemetry.

Microsoft has released a set of privacy settings for Office, one of which enables users to configure the type and amount of diagnostic (i.e., telemetry) data that Office may send to Microsoft. When deployed, it is available in the form of a group policy setting. It allows users to configure one of the following diagnostic data levels: required, optional, or neither. The report we produced:

analyzes the impact of the required, optional, and neither diagnostic data levels on the output of diagnostic data produced by Office; and
provides and evaluates approaches for partially or fully disabling the output of diagnostic data produced by Office.

The report is available here (in English).

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Misc

January 14, 2020 by Aleksandar Milenkoski

Windows Insight: The Windows Telemetry ETW Monitor

The Windows Insight repository now hosts the Windows Telemetry ETW Monitor framework. The framework monitors and reports on Windows Telemetry ETW (Event Tracing for Windows) activities – ETW activities for providing data to Windows Telemetry. It consists of two components:

the Windbg Framework: a set of scripts for monitoring Windows Telemetry ETW activities. The scripts are fed to a running windbg instance, connected to the Windows instance whose Windows Telemetry ETW activities are monitored.
the Telemetry Information Visualization (TIV) framework for visualization of information and statistics. The TIV framework is a set of Python scripts that visualize information and statistics based on the data produced by the Windbg Framework. The output of the TIV framework is a report in the form of a web page.

The Windows Telemetry ETW Monitor has been tested on Windows 10, version 1909.

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Events

November 25, 2019 by Aleksandar Milenkoski

TROOPERS20 Training Teaser: Insight Into Windows Internals

Windows 10 is one of the most commonly deployed operating systems at this time. Knowledge about its components and internal working principles is highly beneficial. Among other things, such a knowledge enables:

in-depth studies of undocumented, or poorly documented, system functionalities;
development of performant and compatible software to monitor or extend the activities of the operating system itself; and
analysis of security-related issues, such as persistent malware.

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Misc

October 30, 2019 by Aleksandar Milenkoski

Windows Insight: Code integrity and WDAC

The Windows Insight repository now hosts three articles on Windows code integrity and WDAC (Windows Defender Application Control):

Device Guard Image Integrity: Architecture Overview (Aleksandar Milenkoski, Dominik Phillips): In this work, we present the high-level architecture of the code integrity mechanism implemented as part of Windows 10.
Windows Defender Application Control: Initialization (Dominik Phillips, Aleksandar Milenkoski): This work describes the process for initializing WDAC performed by the Windows loader and the kernel when Windows 10 is booted.
Windows Defender Application Control: Image verification (Aleksandar Milenkoski): This work discusses the workflow of WDAC for verifying images.

– Aleksandar Milenkoski