If you ever encounter someone who hacks websites, shoot to kill.
I’m back, but it’s going to take a while to restore everything.
Update: A Christmas present from my ISP:
(I’m posting this from the office where the internet does work on this lovely brown Christmas morning.)
Occasionally my server gets several hundred successive attempts to load various files I don’t have, apparently looking for known content management systems which have known bugs. I assume the same was done to you, and they found your wordpress installation. My condolences.