Category: Active Directory

Mitigating attacks on your Active Directory network

Microsoft released a new whitepaper this week that gives an insight in why you should protect your privileged accounts. One of the techniques described is the PassTheHash attack which is a sophisticated attack but fairly easy to execute. These attacks have been seen in the “field” and are being used today. If you work with […]

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Back to the future…

Did your AD jump back to the year 2000 during the past weekend? .. This could have happened if you are syncing your time with the USNO.NAVY.MIL, as they apparently had a disruption on the 19th. see http://tycho.usno.navy.mil/ntp.html   But if time jumped back on your AD, you’re in trouble.. and the way to get […]

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Import/Export Active Directory data…

I was trying to get a test environment up and running that should reflect the production environment of my customer (off course at the customers site.. secured and all).. one task was to duplicate the OU structure, group structure and user information (without passwords). Browsing through the web I found a VBS script that can […]

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Windows 2008R2 features part VI: Managed Service Accounts – delegation

In a previous entry I’ve explained how you can run services under the new Managed  Service Account. Say now that we want to use this service account in combination with Kerberos and the account needs to be trusted for delegation. We set an SPN to it, but in the Active Directory Users and Computers, we seem to be unable to find the trusted for delegation option.. Let’s take a closer look at these accounts once they have been created, to do this we’ll be using ldp.exe

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Cross Forest Authentication NTLM

So we’ve seen how a trust is setup, and how we can manipulate the domain controllers involved, can we do the same for authentication traffic? The answer would be yes, but why is it a yes, and how is the main question.

While many believe WINS or LMHOSTS can help us on external (non-forest) trusts, we dive into a packet capture that has captured the opening of a fileshare on a remote forest.

For this demo, I have installed a resource server in the forestroot domain, and a RIVER client on the OCEANFLOOR domain.

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Creating trusts (as follow up to…)

So I was wondering the following, how do all the domain controllers know that the trust is established, since (see previous post) we cannot accurately say which domain controller is being used..

When we have the same problem with user passwords, the PDC gives the vote whether the password (just changed) for the user is valid. The same seems to apply for Trusts. When running a trace while creating the trust on a “regular” domain controller and not the PDC, we can find out how that is accomplished. For this, I have installed a domain controller called MICHDC01 which is on the (newly created) LAKES site.

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Cross Forest Authentication part 2 – Creating trusts

In part of the the forest authentication blog post, we’ve seen that a particular path is used depending on Kerberos or NTLM authentication. We’ve also seen that domain controllers rely on other domain controllers of the forest to find the right domain (and thus object in the AD). The question now is, which domain controller of the other forest is used to authenticate the user? What happens during a trust creation, do we really need the PDC emulator? Will LMHOSTS still help us, like it did in the old days?

Those questions we will answer in this series of authentication across trusts part 2, 3 etc..

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FIM RC1 U3 and admin rights

So I tried to install the FIM RC (u3) in a demo environment, and what a hush hush was that.. My setup was fairly easy, all (except SQL) on a single box.. offcourse reading is not my best skill, but the install went fine.. and the portal was ready for the administrator account (installed it with). It opened on the fim server without a problem, but getting it to work remotely, that was another problem..

The guide tells you to register SPN’s for the Kerberos to work if the FIM Portal and FIM service are on seperate servers, but ALSO if you want to use the FIM password reset extension.. however registering the http/servername to a service account renders the remote login useless.. you will receive an HTTP Error 401. The requested resource required used authentication.

If you where to google (or bing) on that error code the links tell you to disable Kernel Mode kerberos in IIS.. well that kinda did NOT do the trick either and although the Sharepoint site comes up then, the FIM portal dies..

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Query AD for information

So.. been busy lately.. but here’s a new topic.. Windows 2008? R2? Kerberos? No.. it’s scripting..

I had a customer who wanted to extract information from AD by a custom application. Offcourse we could open port 389 and have them extract the info.. but perhaps it would be easier to just query the Global Catalog (if the info you want is in there)..

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New Active Directory 2008 Forest Recovery Documentation

So you have implemented Active Directory 2008 .. I hope you did some investigation in backup/restore and offcourse you must update your disaster recovery documentation now.. to help you on your way Microsoft has released a new whitepaper on Forest Recovery for Windows 2008… read before and while fixing your AD.. (preferably before ) http://www.microsoft.com/downloads/details.aspx?familyid=326C8A7A-DCAD-4333-9050-A6303FF3155C&displaylang=en

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