A Hacker Was Moving My Cursor, But Sandboxed

[Lode]

At one time I saw my cursor move away when I tried to close my browser. I had slid it towards the right top corner using my touchpad, but did not quite reach it. So I lifted my finger to slide it a bit further, this time to reach and tick on the white X in the red square. But the moment I lifted my finger that little white arrow shot to the left! I tried again, and the same thing happened. Then I noticed my hard drive LED being lit up almost without even blinking. Someone was loading lots of stuff on my laptop, or doing I don't know what...

Then I realized it was all in the sandbox, and relaxed. I let him do his thing for maybe a minute, just to watch it. Then I decided to end it, and quickly moved the cursor to the Sandboxie icon on the tray, and hit "Terminate all programs." That was it. everything back to normal.

Of course I let my AV scan, but nothing found.