Is 'Norton Security Scan' legitimate?

Hi there,

 

Yesterday I had a window pop up withought warning [and without an internet browser open] to instal a program called 'Norton Security Scan'.

 

The installation gave me no chance to exit - and only to proceed installing.  I did not download anything from Norton, nor did I allow anything from Norton to be saved to my computer.  The only thing I allowed that day was an update from Divx.

 

Is this a fake?   If so I'm sure it should be reported, my existing Antivirus did not pick it up though.

 

Cheers.