No, our proctors cannot access your computer files without your knowledge. Everything they do will be shown on your screen and they cannot perform "hidden" actions. This access is only granted with your explicit permission and after you've clicked a button to confirm.
Proctors have the ability to view the screen and utilize the mouse and keyboard as if they were sitting next to you. Once the exam starts, your proctor will monitor everything on the computer screen, but can no longer utilize the your mouse and keyboard.
During the entire process, a chat box is running on your computer and you can see what permissions the proctor currently has at any time. The entire chat session log is saved, including a permanent record of what actions the proctor took while accessing your computer.