The Department of Homeland Security has posted an alert (TA16-105A) advising users to uninstall QuickTime for Windows immediately. The alert aligns with a Trend Micro Urgent Call to Action posted on April 14, 2016. It states, since Apple will no longer be issuing security updates for QuickTime on the Windows platform, the software may be vulnerable to attacks. The advisement does not apply to QuickTime on MAC OSX.
Although Trend Micro acknowledges there are no known active attacks targeting QuickTime, the only way to protect Windows systems is to uninstall the software. Microsoft Media Player and the open source VLC for Windows are viable alternatives, supporting Apple (.MOV) and other popular media file formats.
QuickTime for Windows may be uninstalled by using Windows Control Panel / Programs. More information on uninstalling programs can be found at Microsoft.com, or contact your IT support professional for assistance.