Monitor internet usage

[toohuge]

PH,

I have just checked my internet usage from our internet provider and this month, I have hit just under 400GB! The previous months have been around 50GB or so.

I was streaming a few videos and music etc. but that amount of data seems insane.

I am concerned that one of my computers has a virus and is sucking internet data whilst it is on - is there a way to instantly monitor internet usage through my router?

Thanks
Chris

[toohuge]

Thank you gents. I have AVAST on both of the computers connected to the network, one of which is a Mac and both of these are showing clear.

I will try the other suggestions above to see where this leakage is coming from .

Thanks for the suggestions.
Chris