This indicates an attack attempt to exploit a Memory Corruption vulnerability in Microsoft Office.
The vulnerability is due to improper handling of a certain component when the vulnerable software attempts to access a specially crafted RTF file. An attacker can exploit this to execute arbitrary code within the context of the logged in user via a crafted RTF file.
Microsoft Word 2016 (32-bit edition)
Microsoft Word 2016 (64-bit edition)
Microsoft SharePoint Enterprise Server 2016 64Bit Edition
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.