This indicates an attack attempt to exploit an Insecure Library Loading vulnerability in Microsoft Windows.
The vulnerability is due to an error while the affected software loads dll files. An attacker can exploit this by tricking an unsuspecting user into opening a file from a directory and execute arbitrary code within the context of the application.
Microsoft .NET Framework 4.6
Microsoft .NET Framework 4.6.1
System Compromise: Remote attackers can execute arbitrary code within the context of the currently logged in users.
Apply the most recent upgrade or patch from the vendor.