Help Data Usage Excessive

I am trying to work out where all my data is going and the only thing I can find is Bitdefender. I used 3 gigs today and the only thing that happened in this time was an update from Bitdefender, everything else was turned off an every one was at work


Is this possible??? and what do I do I am blowing my plan each month because of this. I am nearly at exiting it completely.