This indicates an attack attempt against a DLL hijacking vulnerability in Microsoft Office.
The vulnerability is due to a lack of input validation in Microsoft Office when handling the loading of DLL files. A remote attacker can exploit this to gain complete access to a vulnerable system.
Windows Server 2008
Windows Server 2008 R2
Windows 8 and Windows 8.1
Windows Server 2012 and Windows Server 2012 R2
Windows RT and Windows RT 8.1
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.