PSD2 – Mandatory Account Access for Third Party Providers

On September 14th the final deadline of complying with the new Payment Service Directive PSD2 will be reached. Among other things, this directive will bring quite a few technical challenges for credit institutions. These include new requirements on two-factor authentication and API access for third parties. In this blog post we will give a short overview of what this means for banks from a security perspective and outline a few of the security-related issues based on what we have been observing during recent assessments of such APIs.

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A Follow-Up on the Heisec Webinar on Emotet & Some Active Directory Security Sources

Some weeks ago, Heinrich and I had the pleasure to participate in the heisec-Webinar “Emotet bei Heise – Lernen aus unseren Fehlern”. We really enjoyed the webinar and the (alas, due to the format: too short) discussions and we hope we could contribute to understand how to make Active Directory implementations out there a bit safer in the future.

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LibreOffice – A Python Interpreter (code execution vulnerability CVE-2019-9848)

While waiting for a download to complete, I stumbled across an interesting blogpost. The author describes a flaw in LibreOffice that allowed an attacker to execute code. Since this was quite recent, I was interested if my version is vulnerable to this attack and how they fixed it. Thus, I looked at the sources and luckily it was fixed. What I didn’t know before however was, that macros shipped with LibreOffice are executed without prompting the user, even on the highest macro security setting. So, if there would be a system macro from LibreOffice with a bug that allows to execute code, the user would not even get a prompt and the code would be executed right away. Therefor, I started to have a closer look at the source code and found out that exactly this is the case!


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Emotet at Heise, Emotet there, Emotet everywhere – Dissection of an Incident

After the Emotet Incident at Heise, where ERNW has been consulted for Incident Response, we decided to start a blogpost series, in which we want to regularly report on current attacks that we observe. In particular we want to provide details about the utilized pieces of malware, different stages, and techniques used for the initial infection and lateral movement. We hope that this information might help you to detect ongoing incidents, apply countermeasures, and in the best case to figure out proactive countermeasures and security controls beforehand.


ERNW supports Heise in Incident Response

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IPv6 Surveys / Application Space

In some organizations we work with a certain state of IPv6 deployment has been reached in the interim which includes, among others, the following aspects:

  • the network infrastructure is IPv6-enabled (incl. interface addressing, routing [protocols] and the like).
  • parts of supporting services (security functions, monitoring, system management) include IPv6 in a proper way.
  • 3rd party providers have been contractually obliged to deliver their services in an “IPv6-enabled” mode (as opposed to only being “IPv6-capable” which was the standard requirement in many RFIs during earlier years).

It might then happen that networking people (who often are the initial motivators for deploying IPv6) in such organizations are stating, when asked about IPv6: “it’s [mostly] done”.
Point is that, alas, this does not necessarily mean that a single service or application is *actually using* IPv6, so while the above certainly constitutes an achievement it might not even be halfway through.

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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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Emotet im Active Directory: Es kann jeden treffen – aber Jeder kann es dem Angreifer schwer machen!

Heise berichtet aktuell öffentlich über die Emotet-Infektion im eigenen Haus, bei dessen Aufklärung ERNW unterstützte. Damit liefert Heise Informationen zum Verlauf aktueller Angriffe, aber insbesondere auch wertvolle Einsichten zu Vorbeugung, Erkennung, Analyse und Gegenmaßnahmen aus eigener Erfahrung, wie sie nur selten der Öffentlichkeit preisgegeben werden.

Ein Team aus Incident-Response Spezialisten der ERNW Research unterstützte Heise bei der Analyse und Rekonstruktion des Vorfalls und analysierte die Schadsoftware, um deren Ausbreitungswege nachzuvollziehen und IoCs (Indicators of Compromise) zu extrahieren. Hierdurch konnten effektive Gegenmaßnahmen entwickelt und gemeinsam mit Heise erfolgreich umgesetzt werden.

Im Zuge dessen unterstützten Active-Directory-Spezialisten der ERNW Heise bei der Konzeption und dem Wiederaufbau eines neuen Active Directory. Im heisec-Webinar am 3. Juli berichtet Heise über den Incident und die wichtigsten Erkenntnisse daraus. Dabei sein werden zwei unserer Active Directory-Security-Spezialisten. Sie werden Konzepte und Verfahren für ein sicheres, resilientes und trotzdem betreibbares Active Directory vorstellen und den Teilnehmern mit Tipps für Containment nach einer Infektion und in gemeinsamer Diskussion zur Verfügung stehen.

Bei Interesse an diesem Thema beachten Sie auch die vielen Vorträge internationaler Active Directory-Security-Spezialisten des Active Directory Security Tracks auf der diesjährigen Troopers (so wie unsere eigenen Beiträge dazu, wie etwa hier und hier) und unsere Workshops zu Active Directory-Sicherheit und Inicdent Response.

Wir wünschen allen Lesern ein schönes verlängertes und hoffentlich Incident-freies Pfingstwochenende!


Friedwart Kuhn & Andreas Dewald.

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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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