This indicates an attack attempt to exploit a remote Code Execution vulnerability in Microsoft Office.
The vulnerability is due to the way the vulnerable application loads DLL file. A remote attacker can exploit this to trick an unsuspecting user into opening a harmless file which leads to loading and executing of a malicious DLL.
Microsoft Office 2007
Microsoft Office 2010
Microsoft Office 2013
Microsoft Office 2016
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrades or patches from the vendor: