Compass Security Blog

Offensive Defense

Make the most out of BloodHound

During internal assessments in Windows environments, we use BloodHound more and more to gather a comprehensive view of the permissions granted to the different Active Directory objects. In this post, we’ll show an advanced usage of this tool by using our additional queries.

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Relaying NTLM authentication over RPC

Since a few years, we – as pentesters – (and probably bad guys as well) make use of NTLM relaying a lot for privilege escalation in Windows networks.

In this article, we propose adding support for the RPC protocol to the already great ntlmrelayx from impacket and explore the new ways of compromise that it offers.

This vulnerability was discovered by Compass Security in January 2020, disclosed to Microsoft Security Response Center and assigned CVE-2020-1113 as identifier.

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New SMBGhost Vulnerability Affects Modern Windows Systems

A new vulnerability (CVE-2020-0796) affecting SMBv3 has been discovered. The community has started to name this vulnerability SMBGhost because everyone knows this vulnerability is present but no additional details are available. Microsoft also released the advisory ADV200005. [1]

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Hidden Inbox Rules in Microsoft Exchange

Contents Introduction Attack Overview Step-by-Step Detection Email Clients Administration Tools Exchange Compliance Features MAPI Editor Eradication Microsoft Security Response Center Swiss Cyber Storm 2018 Conclusion References Introduction In recent investigations, Compass recognized a raise in popularity for attackers to compromise Microsoft Exchange credentials. As one of the first steps after having obtained the credentials (most […]

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No need to break in, use the backdoor

The idea Some time ago I read a tweet about hunting so-called “sticky-keys backdoors”, referencing a presentation at DEFCON 24, https://www.youtube.com/watch?v=EAYtRQKfna0 In addition to the presentation, the team released a tool called “Sticky Keys Slayer” that is publicly available on GitHub, https://github.com/linuz/Sticky-Keys-Slayer/ The sticky-keys backdoor is using a simple trick. On a Windows system, it is possible […]

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Exchange Forensics

Introduction The number one form of communication in corporate environments is email. Alone in 2015, the number of business emails sent and received per day were estimated to be over 112 billion [1] and employees spend on average 13 hours per week in their email inbox [2]. Unfortunately, emails are at times also misused for illegitimate […]

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Windows Phone – Security State of the Art?

Compass Security recently presented its Windows Phone and Windows 10 Mobile research at the April 2016 Security Interest Group Switzerland (SIGS) event in Zurich. The short presentation highlights the attempts made by our Security Analysts to bypass the security controls provided by the platform and further explains why bypassing them is not a trivial undertaking. Windows 10 Mobile, which […]

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Presentation about Windows Phone 8.1

Earlier this month, my colleague Cyrill Bannwart and I held two Compass Security Beer Talk presentations in Bern and Jona about Windows Phone 8.1 security. The slides are now online and cover: Our (unsuccessful) black box attempts to break out from a Windows perspective A review of the implemented security features in Windows Phone 8.1 from a mobile perspective Our findings […]

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Vom Domäne Benutzer zum Domäne Administrator (exploit MS14-068)

Der von Microsoft publizierte “out-of-band” Patch MS14-068 [1] (Vulnerability in Kerberos Could Allow Elevation of Privilege – 3011780) behebt eine Schwachstelle in Kerberos, welche es einem normalen Benutzer erlaubt, administrative Privilegien in der Windows Domäne zu erlangen. Die ersten öffentlichen Artikel [2] mutmassten, dass die Kerberos Services den CRC32 Algorithmus als gütlige Signatur auf Tickets […]

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Disabling Viewstate’s MAC: why you deserve having now a broken ASP.NET web application

Lots of things happened since my first (and unique) blog post about ASP.NET Viewstate and its related weakness. This blog post will not yet disclose all the details or contain tools to exploit applications, but give some ideas why it’s really mandatory to both correct your web applications and install the ASP.NET patch. Back in […]

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