This indicates an attack attempt against an Information Disclosure vulnerability in Microsoft XML Core Services.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted HTML file. A remote attacker may be able to exploit this to gain unauthorized access to sensitive information on the affected machines via a crafted HTML file.
Windows Server 2008
Windows Server 2008 R2
Windows Server 2012 and Windows Server 2012 R2
Windows RT 8.1
Windows Server 2016
Server Core installation option
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems
Apply the most recent upgrade or patch from the vendor.