Exchange Server: Reinstallation without data loss (e.g. after an attack)

Many admins are currently reporting a successful attack on their Exchange server. Many are finding evidence of unauthorized access or even an installed web shell. Many are now unsure what to do or how to proceed. Some are now implementing IIS rewrite rules or deactivating the UM services, for example, as described in this article by ... Read more

Exchange Server: New security updates (March 2021)

Microsoft has released new security updates for Exchange Server 2013, 2016 and 2019. The prompt installation of the security updates for the affected Exchange versions is recommended by Microsoft, as the vulnerabilities are already being exploited: As active exploitation of related vulnerabilities in the wild is known (limited targeted attacks), our recommendation is to install these updates immediately to prevent ... Read more

HowTo: Zevenet Community Loadbalancer for Exchange 2019

Zevenet Loadbalancer is the successor to Zen Loadbalancer, for which I wrote a howto some time ago. Zevenet Loadbalancer is particularly suitable for test environments as it is quick to install and configure and is also free of charge. So here is an updated how-to on Zevenet and Exchange 2019. The Zevenet load balancer ... Read more

New security updates for Exchange Server 2016 - 2019 (February 2021)

Microsoft has released new security updates for Exchange Server 2016 - 2019. This is a fix for the following vulnerability: CVE-2021-24085: Microsoft Exchange Server Spoofing Vulnerability However, the vulnerability is listed as "Low" severity and an attacker must have Exchange Server credentials to exploit the vulnerability: An ... Read more

VMware vSphere VMs: Caution with vMotion operations and time-critical VMs such as domain controllers

I recently fell into this trap, because with time-critical VMs, such as domain controllers, which are operated on VMware vSphere, you have to pay attention to a small peculiarity. Since an incorrect time can have far-reaching consequences, here is a short article on the subject. The following problem has occurred. An NTP server ... Read more

Quick tip: "Why did the computer shut down unexpectedly?" appears at every login

Windows servers may display the message "Why did the computer shut down unexpectedly" at every login if the server had previously crashed. Although the message can be confirmed for the current session, it reappears the next time the user logs on: This small problem occurs when a user who is not the "Administrator" logs on, ... Read more