deskthority

.. you mean virus software that attacks keyboard firmware ?

Unlikely that a virus did that. A malicious program would want to hide itself from the user and not alert them of its presence by pressing the whole top row of keys.

Probably just a defect of the keyboard controller.

Yeah, I think the most likely problem is that you got 2 boards from the same bad batch.

But if you have a second computer to test with, when you get the 3rd board, try it there first before you plug it in to your main computer.