Boot.Alworo

Twice today I have received warning from Norton that my system has a Virus. 

 

I've run full antimalware scans, as well as full virus scans. Cleared my caches and registry.

 

The notification said it was a 'Boot.Alworo' and that it was full resolved. That was the first time, but it appeared again later in the afternoon.

 

Should I be worried about an internal virus or is this someone trying to attack my computer?

 

I've attached a txt file with a little information about the threat.