Lots of reports about reports aboit reports that Quicktime for Windows is being discontinued, but if there's anything from Apple to corroborate it I can't seem to find it. It seems the problem may lie in the QT Windows browser plugin rather than the application itself, so disabling/uninstalling just the plugin may do the trick. Be nice to hear from Apple about this though, to confirm if there really is a security issue involved and Trend Micro, to whom all sources eventually point, haven't made a mountain out of a molehill.

Personally I'd be glad to see the back of QT, on OS X just as much as Windows. 20-odd years ago it was useful, but who these days puts out anything aimed at being played in Quicktime? Even on Macs it grabs file associations with the result that videos tend to default to it rather than the much more capable in all kinds of ways iTunes, hangs around consuming resources (OK, very few resources, but even so...) and generally makes a nuisance of itself. If iTunes still hooks QT in some way then rebuilding iTunes to operate without it would seem the best idea.

I believe it was more the plug ins sonar was being shipped with that required Quicktime.
sonar never needed quicktime to function fully.

Homeland Security warns Windows PC users to uninstall Quicktime

http://www.foxnews.com/tech/2016/04/18/homeland-security-warns-windows-pc-users-to-uninstall-quicktime.html?intcmp=hpbt3
 

i got rid of quick time also. i found it was needed by other things but not really needed. ik's amplitube for one but it seems it was only for the playing back of things you may have recorded with the looper which you don't have to use or save to the format hat required quick time. over all i have not experienced any ill effect from not having quick time. i never installed it myself or actually used it but it was installed by another products that said it needed it for such and such. i never really liked quick time anyway.

Here's the post I created yesterday in the software forum:  OK, I uninstalled QT yesterday, and today I opened a project with Addictive Drums in it, and found they were no longer recognized.  This was true in both my cwp. files and my cwb. files, as well as my backup files.  So, I did a system restore to the day before I uninstalled QT, and now my AD files show up again.  Has this happened to anyone else, and if so, is there a way to make that not happen again?  Grateful for any advise.
 
I got no responses to this, yet, but I'm still curious as to why that happened.

From the Sony Vegas users site.... but likely applies to other programs like sonar as well
 
The vulnerabilities were found in the Windows QuickTime Player. You could always delete or rename the player executable and not have to worry. I don't think many users actually use the player. They just need the codecs to process QuickTime MOV or other files. All you need to do is stop using the QuickTime Player which you probably don't use anyway. No need to panic. You can rename the quicktime player.exe file to something like quicktime player.exe.OLD  and reboot to disable it without loosing the codecs. If it causes a problem rename it back and reboot and all will return to normal.