This just happened to me. its like the ccsvchst.exe process just started hanging at 25% and didn't budge. norton was perfectly fine otherwise. i tried shutting off antivirus and firewall and turning it back on.
I just updated my bios and restarted the computer before this happened. I checked in the norton tasks under performance tab and it appears pulse updates had run right before it got stuck. I manually updated again...but it still stayed stuck at 25%. So I restarted the pc.
i didn't hear my hdd cachin either, like i normally hear norton doing to my hdd. i sometimes feel norton the norton idle scans last way too long. and lately they seem to be worse. but this issue has never happened to be me before where it got permanently stuck on exactly 25%/