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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Misc

Windows Insight: The TPM

The Windows Insight repository currently hosts three articles on the TPM (Trusted Platform Module):

  • The TPM: Communication Interfaces (Aleksandar Milenkoski): In this work, we discuss how the different components of the Windows 10 operating system deployed in user-land and in kernel-land, use the TPM. We focus on the communication interfaces between Windows 10 and the TPM. In addition, we discuss the construction of TPM usage profiles, that is, information on system entities communicating with the TPM as well as on communication patterns and frequencies;
  • The TPM: Integrity Measurement (Aleksandar Milenkoski): In this work, we discuss the integrity measurement mechanism of Windows 10 and the role that the TPM plays
    as part of it. This mechanism, among other things, implements the production of measurement data. This involves calculation of hashes of relevant executable files or of code sequences at every system startup. It also involves the storage of these hashes and relevant related data in log files for later analysis;

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Misc

Windows Insight: A New ERNW Repository

We are glad to announce the Windows Insight repository. The content of this repository aims to assist efforts on analysing inner working principles, functionalities, and properties of the Microsoft Windows operating system. This repository stores relevant documentation as well as executable files needed for conducting analysis studies.

Some of the content of this repository has been created in the course of a project named ‘Studie zu Systemaufbau, Protokollierung, Härtung und Sicherheitsfunktionen in Windows 10 (SiSyPHuS Win10)’ (ger.) – ‘Study of system design, logging, hardening, and security functions in Windows 10’ (eng.). This project has been contracted by the German Federal Office for Information Security (ger., Bundesamt für Sicherheit in der Informationstechnik – BSI). The work planned as part of the project is conducted by ERNW GmbH, starting in May 2017.

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Misc

Heise Security Tour: Offensive PowerShell

Dominik Phillips and I are taking part in a tour organized by Heise Security – the Heise Security Tour. We give a talk titled “PowerShell: Attack under the radar”. In this talk, we provide an overview of the architecture of PowerShell and show how attackers may use PowerShell for malicious purposes. We demonstrate PowerShell post-exploitation activities implemented as part of publicly available frameworks, such as Empire. We also discuss a security concept for defending against such activities.

You can find the slides of our talk here (in German).

– Aleksandar Milenkoski

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Events

TROOPERS19 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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