Apple has released QuickTime 7.7.6 for Windows 7, Vista, XP SP2 or later to address multiple vulnerabilities, some of which may allow remote attackers to execute arbitrary code or cause a denial of service.
Users and administrators are encouraged to review Apple Support Article HT6493 and apply any necessary updates.
https://www.us-cert.gov/ncas/current-activity/2014/10/23/Apple-Releases-Security-Updates-QuickTime.
Bailey's Tech Repair Service Blog 