Trend Micro reports "two critical vulnerabilities affecting QuickTime for Windows", and - since Apple will no longer be issuing updates for the product - recommends removing it from computers as soon as possible.
An installed copy of QuickTime was a requirement for our QuickTime DirectShow Source filter. Because of the existing security threats, we have no option but to discontinue this product and strongly suggest that it is replaced with one of the following alternatives:
The Multi-Format Source DirectShow filter has all supported splitters and codecs built into a single source filter, which makes playback graphs extremely simple.
MFormats SDK is a full-time software development framework, capable of completely replacing your DirectShow stack. It is extremely easy to use (especially compared to coding DirectShow filters), and the best way to give it a try is to use it as a codec library in an existing multimedia application.
Both options provide support for the same set of codecs (including QuickTime, of course); both have licensing options for either one developer or a team of 4 developers.
Unfortunately, it will not be possible to renew your existing QuickTime Source subscription.