Misc

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

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

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

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

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

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.

wintel

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

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Events

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

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

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Misc

Windows Insight: Virtual Secure Mode

The Windows Insight repository currently hosts four articles on VSM (Virtual Secure Mode):

  • Virtual Secure Mode: Architecture Overview (Aleksandar Milenkoski): In this work, we discuss the architecture of a virtualized Windows environment.
  • Virtual Secure Mode: Communication Interfaces (Aleksandar Milenkoski): In this work, we discuss the communication interfaces that VSM implements: Isolated User Mode (IUM) system calls, normal-mode services, secure services, and hypercalls.
  • Virtual Secure Mode: Protections of Communication Interfaces (Aleksandar Milenkoski): This work discusses implemented mechanisms for securing the above VSM communication interfaces. This includes restrictions on issuing hypercalls, data marshalling and sanitization, and secure data sharing.
  • Virtual Secure Mode: Initialization (Dominik Phillips, Aleksandar Milenkoski): This work describes the process for VSM initialization activities performed by the Windows loader and the Windows kernel when Windows 10 is booted.

– Aleksandar Milenkoski

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