Full System Scan won't stop

I have Norton 360 v6 on my 1st laptop computer (my computer knowledge is "basic/novice", by the way) and I recently ran a Full System Scan for the 1st time (I've run Quick Scans many times without probs- they detected & resolved numerous cookies only on each occasion). The reason for running the scan was I got spooked after receiving a "Delivery Status Notification (Failure)" email after sending off a job application email. I didn't know what it meant so googled it and found out they could be dodgy in some way. Unfortunately, prior to that I may well have opened an attachment on the possibly dodgy email but can't remember what, if anything, it said (I deleted the emails).

 

Anyway, I ran the full scan and it quickly detected & resolved 11 "threats" (I think that was the term) then carried on for about an hour or more without detecting further threats before changing to a smaller box which won't stop and has stayed in "processing" mode for over a day now. Both the "cancel" and top corner "X" buttons are grey & don't work so I don't know what's happened or how to resolve prob. I've actually since run a new Full Scan despite this old one still "processing" & it only lasted about 5 mins and declared no issues detected. My computer is working fine in all respects, other than having this unremovable & slightly worrying scan box "processing" away.

 

Not sure what I should do- anyone know?

 

Regards,

David