Who downloaded to me?

Is there any utility that will tell me after the fact who downloaded anything to me? In my case just now, it's probably an update of some kind. But it has already happened because I see in Networx > General > Today that sometime this morning about 600 mb was downloaded to my computer. Is there any record of the source of this download in Win7, Firefox or some utility I can use to discover what today's download was, reveal its destination on my machine, and to maintain an automatic log of same in the future? I already know about update permission settings, inbound and outbound rules for software and Windows Update, etc.. But, apparently, I don't know enough because I have no idea what that 600mb was this morning and where on my machine it now resides..