Well, being away from my log for a while has left some interesting bread crumbs to sift through.
For example, I have noted that someone in Iran (80.191.136.xx) has been trying to attack my site.
I tracked back a couple very sloppy attempts to the Isfahan municipality computer services organization.
Basically, in the latest attempt, they have been searching for a vulnerable version of wp-trackback.php, and submitting “‘ and 1=1” to post.php.