Compass Security Blog

Offensive Defense

Relaying NTLM authentication over RPC again…

A little bit over a year ago, I wrote an article on this blog about CVE-2020-1113 and how it enabled to execute code on a remote machine through relaying NTLM authentication over RPC triggering a scheduled task on the remote system. History repeats itself and a vulnerability of the same category has been fixed by Microsoft in June this year.

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Security Best Practices for On-Premise Environments

Due to recent developments we figured it would be great to contribute a cheat sheet and create security best-practices on how to tie down a Microsoft on-prem environment. Our work mostly relies on MS recommendations. However, we put some effort to really condense it to the essence. We hope to see this applied everywhere and thus open-sourced everything in our GitHub repository.

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101 for lateral movement detection

The article discusses the very basics to keep systems ready for analysis of lateral movement. We present some guidelines in form of a cheat sheet and a tool (Readinizer) that you can run, to ensure that everything is set up as in the guidelines provided.

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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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