Well, it got worse. Yesterday it spread to my TV. It was flashing black and back again like 3 times every 5 seconds for about a minute. Then I turned it off and turned the whole media box off (which does TV and internet in one). Now today turning it back on it seems normal again and the flashing is gone. But yesterday to me that was a signal that it was definitely a form of malware.

So I contacted Avast, they can only guarantee safety for Windows, and not the modem/tv or anything related to Linux.

And next time it happens I can contact my internet/tv provider.

So I myself don't think it's hardware. I had problems on both my Dual Boot PC and then the laptop. Then I saw screens flashing by on both my Android Phone and Android tablet. And then the TV stuff. So yeah if that changes things for you guys let me know. But if I can't solve this some other way I'm going to prepare to stick to Windows.