A few months ago a zerologon exploit was released and this exploit was able to do damage to an Active Directory environment. Microsoft released a patch in the next set of updates and in a 2x part video, we show you how an unpatched system is compromised vs a patched system. Here is the CVE detail: CVE-2020-1472
Take note that Exchange relies on Active Directory and if it’s exploited, Exchange is not going to function.
Below are the three videos:
Unpatched System (Warning)
Unpatched System (Exploited)
Be sure to update if you have not. Windows updates are very important, especially the security ones.
Hope it helps.