I am running Ubuntu 14.04 LTS and today saw a bit of a weird thing happen.
I left my computer to get a coffee, and when I got back the desktop had locked and was showing the login-screen.
All good right? (Edit, the coffee machine is basically in plain sight of my computer, no-one was even close to it.)
Now, when I started typing, nothing is being entered in the password box like it normally does.
The mouse worked perfectly. There was a prompt in the password box the blinked like it normally does.
I went and asked a colleague with more Ubuntu experience but he didn't have a clue.
After trying a few times more with him watching, and in frustration hammering randomly on the keyboard I turned my head away from the screen for a few seconds.
When I turned back, I am logged in and the text editor that is showing is showing lots (perhaps all, I couldn't tell) of the keystrokes I made while doing retries and the above random hammering.
I then though, oh well, that was a first "lag" of the ubuntu gui I had experienced and continued to work until I shut down the computer and went home.
Now when restart the computer I see two new accounts that I don't recognize on login screen. Previously there were only my account and a "Guest" account.
Now there are two more, "test", and "temporary".
This is beginning to feel suspicious and since I am using this computer to access sensitive information I am wondering if anyone has any tips about what can have caused this.
A sidenote, I practically always do the upgrades immediately when Ubuntu prompts for them. I did one of those in the morning today a couple of hours before the strange login-event happened.
I would be glad for any information.