Track Filetransfer

Hello,

yesterday i was in a TeamVIewer session with a friend. When i went to lunch i didn't close TeamViewer, because the dude was inactive and i trusted him. But when i came back at the bottom right there was a TeamViewer notify saying something about "Filetransfer initialized"(can't really remember, but something with filetransfer). I immediatly closed the connection. Now i'm worried if he transfered a virus or stole some of my data. I looked through the log files, but i didn't really know what to look for or how i can see what files he transfered (if he did so).

Any help is greatly appriciated!