I installed the latest stable Catalyst Suite from AMD (14.4), but today I uninstalled it in order to revert to version 13.12. I used the latest version of the AMD Uninstall Utility. As the uninstall was finishing, avast! popped up a warning that AtiHDAudioService was infected with a rootkit. I took the recommended actions of deleting it (if it was even still present) and performing a boot-time scan (currently in progress, and will be for some time).
I can't post any other specifics until after the boot-time scan completes, but I find it hard to believe AMD would release a driver package that contains a root-kit.
I'll post specifics when I can.