Deploying CEP/ CES using a gMSA

The Certificate Enrollment Policy Web Service (CEP) and the Certificate Enrollment Web Service (CES) were introduced with Windows Server 2008 R2 in order to simplify the request for certificates, especially for devices that were not member of a Active Directory domain. The “classic” way of requesting a certificate from a Active Directory Enterprise CA involves LDAP and RPC/ DCOM, which was okay in the early days of Active Directory, but today, with a CA as a tier 0 asset, this is some kind of a problem.

Why you should change your KRBTGT password prior disabling RC4

While chilling on my couch, I stumbled over this pretty interesting Reddit thread: Story Time - How I blew up my company’s AD for 24 hours and fixed it : sysadmin ( Long story short: A poor guy applied some STIG hardening and his Active Directory blew up. Root cause was disabling RC4, which caused Kerberos failures, primarily documented by errors like “The encryption type requested is not supported by the KDC.

Use app-only authentication with the Microsoft Graph PowerShell SDK

In the previous blog post I have showed you how to interactively log in into the Microsoft Graph API. You had to enter a username, a password, and you had to enter a second factor. This is typically not want you want if you want to automate things. But there is another way to get access to the Microsoft Graph API. Create an app registration To get access, you have to register an app in your AzureAD.

Microsoft rolls back decision to block Office macros by default

Scrolling through my Twitter timeline is a common task to start my day. This morning, a tweet from @BleepinComputer has caught my attention. Microsoft rolls back decision to block Office macros by default - @serghei — BleepingComputer (@BleepinComputer) July 7, 2022 My first reaction: WHAT. THE. FUCK?! Microsoft added this as feature 88883 in februrary 2022 to the Microsoft 365 roadmap, and I was pretty happy about this feature. Let’s take a look at this change.

Mail notification for specific Active Directory security events

A customer used PRTG Network Monitor to notify him in case of account lockouts. This worked quite well until we implemented Admin Tiering. In order to get a mail notification in case of an account lockout, or other security-relevant events in Active Directory, I customized some scripts from my PowerShell dump. The solution is pretty simple: I used the Task Planner to run a PowerShell script if a specific event id occurs.

Outlook Web Access fails with "440 Login Timeout"

Today I faced an interesting problem. A customer told me that their Exchange 2010, which is currently part of a Exchange cross-forest migration project, has an issue with Outlook Web Access and the Exchange Control Panel. Both web sites fail with a white screen and a single message: 440 Login Timeout I checked some basics, like certificate, configuration of the virtual directories and I found nothing suspicious. Most hints on the internet pointed towards problems with the IUSR_servername user, which is not used with IIS 7 and later.

Modify ProxyAddresses of Office 365 users without Exchange Online

As part of a Office 365 tenant rebuild, I had to move a custom domain to the new Office 365 tenant. The old tenant was not needed anymore, and the customer had to move to a Non-Profit tenant for compliance reasons. So the migration itself was no big deal: disable AzureAD sync change UPN of all users remove the domain connect the domain to the new tenant setup a new AzureAD sync assign licenses time for a beer That was my, honestly, naive plan for this migration.

Veeam B&R backup failes with "No scale-out repository extents are available"

One of my customers replaced the old Veeam environment with new gear. The HW was pretty simple designed: two HPE ProLiant per server two HPE D3610 enclosures with 6 TB disks ~ 5km between backup server and backup copy destination One server was designed to act as the Veeam backup server and repository, and the second server was designed to act as the backup copy destination. Both servers were running Windows Server 2019 Standard.

Two registry changes to improve physical Horizon View Agent experience

Using physical clients as Horizon View agents is pretty common for me. My office pc, as well as my Lenovo X250 are often used by using the Horizon View Client and the Blast protocol. But as good as the performance is, there were a couple of things that bugged me. On my office pc, I encountered pretty often a black screen, either on first connect, or on reconnect. The typical issue caused by misconfigured firewall policies, but this was completly out of scope in this case, because my collegues never had issues with black screens.

Details on Windows 10 E3/ E5 Subscription Activation

One of my customers purchased a bunch of Microsoft 365 subscriptions in order to use them with Office 365 and Windows 10 Enterprise. The customer called me because he had trouble to activate the Windows 10 Enterprise license. Source: Microsoft/ I would like so summarize some of the requirements in order to successfuly active Windows 10 Enterprise subscriptions. License First of all, there is a licensing requirement. You need at least a Windows 10 Pro or Windows 10 Pro Education.