This KB2964358 security update is currently available via Windows Update and all users, whether you use Internet Explorer or not, are encouraged to install it. To install the update, please open Windows Update and click on the Check for Updates option. Once Windows Update has finished checking, you should see a new update titled Security Update for Internet Explorer 11 for Windows 7 for x64-based Systems (KB2964358). Please select that update and install it immediately.
If you do not see the update installed, check to see if it is installed by clicking on the View Update History option.
Microsoft has also announced that malware is being distributed via email that is claiming to be this update. If you receive an email that is supposedly from Microsoft and that contains an executable please do not run it. Microsoft will never distribute security updates via email.