This is weird.
Today I opened an excel file with LibreOffice. Suddenly I saw the mouse changed color, and stuck to it was a message in Arabic, which changed every second in a loop. I can actually read Arabic so I immediately recognized it as Islamic messages praising Allah (including the Takbir).
Here's a screenshot:
At first I thought this was something with the file, but then I saw that this happens with any LibreOffice program (but only LibreOffice programs), and even when they're open, it only changes the mouse when it's hovering over the LibreOffice program, and goes back to normal anywhere else. Also, re-installing did not
I tried running software updater - but I have an error where it couldn't load some steam repositories, but that seems like a coincidence:
Failed to fetch http://repo.steampowered.com/steam/dists/precise/steam/i18n/Translation-en_US Failed to fetch http://repo.steampowered.com/steam/dists/precise/steam/i18n/Translation-en
Here's another hint - I tried taking several screenshot of several messages, but they all ended up showing the same message (the one above). Hopefully that means anything.
I should note I haven't installed anything fishy lately, and I hardly ever use LibreOffice at all (I prefer Google Drive whenever I need to work with documents), so I'm really unsure as to how this happened.
Anyway, this is scary.