Events

I Have the Power(View): Offensive Active Directory with PowerShell

In his talk I have the Power(View): Offensive Active Directory with PowerShell Will Schroeder, a researcher and Red teamer in Veris Group´s Adaptive Thread Division, presented offensive Active Directory information gathering technics using his Tool PowerView.

PowerView does not use the built in AD cmdlets to be independent from the Remote Server Administration Tools (RSAT)-AD PowerShell Module which is only compatible with PowerShell 3.0+ and by default only installed on servers that have Active Directory services roles. PowerView, however, is compatible with PowerShell 2.0 and has no outer dependencies. Furthermore, it does not require any installation process.

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Events

The Joy of Sandbox Mitigations

This year at TROOPERS16 in Heidelberg we welcomed James Forshaw for his talk about “The Joy of Sandbox Mitigations“.

He is a security researcher in Google’s Project Zero. He has been involved with computer hardware and software security for over 10 years looking at a range of different platforms and applications. With a great interest in logical vulnerabilities he has numerous disclosures in a wide range of products from web browsers to virtual machine breakouts as well as being a Pwn2Own and Microsoft Mitigation Bypass bounty winner. He has spoken at a number of security conferences including Black Hat USA, CanSecWest, Bluehat, HITB, and Infiltrate. Continue reading “The Joy of Sandbox Mitigations”

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Building

TROOPERS16 Training Teaser: Dos and Don’ts of Secure Active Directory Administration

In the last few years, attack techniques which fall in the categories of “Credential Theft” or “Credential Reuse” have grown into one of the biggest threats to Microsoft Windows environments. Microsoft has stated more than one time, that nearly almost all of their customers that run Active Directory have experienced “Pass-the-Hash” (PtH) attacks recently.[1] Once an attacker gains an initial foothold on a single system in the environment it takes often less than 48 hours until the entire Active Directory infrastructure is compromised. To defend against this kind of attacks, a well-planned approach is required as part of a comprehensive security architecture and operations program. As breach has to be assumed[2], this includes a preventative mitigating control strategy, where technical and organizational controls are implemented, as well as preparations against insider attacks. This is mainly achieved by partitioning the credential flow in order to firstly limit their exposure and secondly limit their usefulness if an attacker was able to get them. Although we spoke last year at Troopers 15 about “How to Efficiently Protect Active Directory from Credential Theft & Large Scale Compromise”[3], we would like to summarize exemplary later in this post Active Directory pentest findings that we classified in four categories in order to better understand what goes typically wrong and thus has to be addressed. For a better understanding of the overall security goals, we classified the findings as to belonging as a security best practice violation of the following categories: Continue reading “TROOPERS16 Training Teaser: Dos and Don’ts of Secure Active Directory Administration”

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Breaking

Investigating Memory Analysis Tools – SSDT Hooking via Pointer Replacement

In this blogpost we will briefly explain a well known Syscall hooking technique (a more detailed explanation can be gathered from e.g.  http://resources.infosecinstitute.com/hooking-system-service-dispatch-table-ssdt/) used by multiple malware samples (like the laqma trojan) and right after discuss how some memory analysis tools have trouble in the analysis and/or reporting of these.
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Events

Black Hat Talks & Papers related to Windows/Active Directory Security

This year’s Black Hat US saw a number of quite interesting talks in the context of Windows or Active Directory Security. For those of you too lazy to search for themselves 😉 and for our own Windows/AD Sec team (who couldn’t send anyone to Vegas due to heavy project load) I’ve compiled a little list of those.

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Building

How to go ahead with future end of life Windows (2003) Servers

Server operating systems with an OS, for which vendor support has ended, come with many risks that have to be considered and addressed. The primary goal should be always to decommission or migrate the majority of end-of-life (EoL) servers to OS versions, supported by the vendor. Here it should be noted that a migration to an up-to-date OS should be preferably done before your organization enters the end of life of that software 😉

However, it must be considered that a number of servers cannot be migrated or shut down (easily) and must remain operational and accessible. Based on a customer project in 2014 we developed a high-level security concept for the secure operation of end-of-life Windows servers. We published this concept in our latest newsletter. You will find it here (https://www.ernw.de/download/newsletter/ERNW_Newsletter_47_Security_Concept_for_End-of-Life_Windows_Servers_signed.pdf)

 

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Misc

Skeleton Key – a Nasty Piece of Malware. Some Remarks.

Just recently, Dell SecureWorks Counter Threat Unit(TM) (CTU) researchers published details (see http://www.secureworks.com/cyber-threat-intelligence/threats/skeleton-key-malware-analysis/ ) on a especially nasty piece of malware that bypasses authentication on Active Directory (AD) systems which implement single-factor (password only) authentication. Once deployed the malware stays quite noiseless in the Domain Controller´s (DC) RAM, and the DC´s replication issues caused by it weren´t interpreted – in this case – during months as a hint for system compromise. Probably the malware´s modification on the LSASS process reduced the DC´s ability to perform DC-to-DC authentication, but this is only speculation and not where we would like to go today.

So, what to do? The relevant mitigations, pointed out by Dell´s CTU, as event log monitoring and scanning processes on suspicious systems with the published YARA signature should be applied.
Still, let’s discuss for a second which long-term, preventative measures could come into play as well. Continue reading “Skeleton Key – a Nasty Piece of Malware. Some Remarks.”

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Building

Some Things to Consider when Using EMET

In the light of the recent release of version 5.0 of Microsoft’s Enhanced Mitigation Experience Toolkit (EMET) on July 31, it seems to be more than appropriate to talk a bit about the new features and some general things to take into account when using EMET (for the new certificate pinning feature of EMET 4.0, see Friedwart’s comment). For all of you who don’t know EMET, in short, it’s a free mitigation tool for Windows developed by Microsoft, helping the user by preventing vulnerabilities in software from being successfully exploited. The tool works by protecting applications via a number of security mitigation technologies, vastly extending Windows operating system mitigation capabilities as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR).

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