Cannot see older events in log files, how can I retrieve them?

Hi! I got hacked and I believe it was with teamviewer_service.exe running in the background.
I checked the log files and didn't see suspicious lines for first glance (I'm not an expert). I tried to check again 4 hours later, but the log files includes only the last 2 hours of events. Every time I check again it removes the lines of older events. Why is that? How can I retrieve the older events for further investigation?