This indicates an attack attempt to exploit a security bypass vulnerability in Microsoft Internet Explorer.
The vulnerability is due to an error when the vulnerable software attempts to access an malicious url. An attacker can exploit this by tricking an unsuspecting user into visiting a malicious webpage and execute arbitrary script within the context of the application.
Internet Explorer 8
Internet Explorer 9
Internet Explorer 10
Internet Explorer 11
System Compromise: Remote attackers can execute arbitrary script code within the context of the target user's browser.
Apply the most recent upgrade or patch from the vendor.