This indicates an attack attempt to exploit an Information Disclosure vulnerability in Microsoft Internet Explorer.
The vulnerability is due to an error when the vulnerable software attempts to handles maliciously crafted web page. An attacker can exploit this by tricking a user into visiting a malicious webpage and gain access to sensitive information within the context of the application.
Internet Explorer 9
Internet Explorer 10
Internet Explorer 11
Internet Explorer 11 on Windows 10
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems
Apply the most recent upgrade or patch from the vendor