First, have you tried restarting just for the heck of it? If it's a temp file somewhere, that might delete it.
Usually, I'd go through each folder and do a get info, looking for the one that appears bigger than its supposed to, then repeat until I've narrowed it down to the one I want, but this won't work for files you don't own, nor invisible files like /etc, if the things you're looking for ended up in one of those locations. Worth a shot, though. The same process can be done in the terminal to get everything, but I can't tell you the command you want.
If that doesn't work, you'd be better off looking at the documentation of MacTheRipper and seeing where it puts stuff so you know where to go with the Terminal to find the offending files.