Exploiting Windows 2008 Group Policy Preferences

Fri 20 January 2012 by trance

Internal network pentesting involving domain controllers requires a few steps in order to gain domain administrator access. One of them usually requires to gain local administrator access to a workstation. In this article, we show how this can be possible from a limited domain user account when specific Group Policy Preferences (GPP) are deployed. GPP are new Active Directory features introduced in Windows 2008; documenting all of them is not the purpose of this article. We focus on the one called Local Users and Groups, that enables a domain administrator to remotely create local accounts on a given list of machines. After explaining how those settings, and especially passwords, are downloaded on domain workstations, we highlight an existing but poorly known vulnerability documented feature enabling any limited domain user to instantly decrypt them.

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Playing with NFC for fun and coffee

Mon 28 November 2011 by trance

RFID and NFS technologies are more and more widespread in our daily life. They can be found in various fields such as access control, tracking systems (objects, animal), and vending machines. Security of these technologies has been the subject of various research work presented and illustrated at conferences like HAR2009, DefCon and Hack.lu. This article is a practical introduction to NFC security by showing how one could abuse a RFID coffee machine. For evident reasons, we will disclose neither the name of the vendor, nor sensitive technical details such as authentication keys. This work has been done for research purpose only, and shall not be used for profit.

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Solving Honynet's Mobile Malware Challenge

Sun 01 May 2011 by trance

Last month, Honeynet members released their last forensics challenge, entitled Mobile Malware. The goal was to analyze a malware installed on a smartphone. The ESEC pentest team won this challenge; our submission is available here. In the meanwhile, this post summarizes our findings as well as the methodology we used to reverse the malware.

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