Open QDAT File
The QDAT file contains the installation data used to install QuickTime.
About QuickTime
QuickTime is a multimedia playback program developed by Apple, capable of handling a wide variety of types of multimedia formats.
The QDAT file can be found on Windows systems under the name QuickTimeInstallCache.qdat, and in this case, be included in an EXE installer file.
That said, the QDAT file is cataloged as a data file.
QDAT files only work to install QuickTime in the operating system, that is, they do not work separately, therefore their manual opening by the user is not recommended.