I am also getting this, I have only had iThemes on for 2 days now so did not know it was a recent event until I read this post. I thought I was just reading the logs incorrectly or had something set up wrong.
The 404 errors are coming from the IP address that resolves to my site (I am hosted on Bluehost); the odd thing about them is that most seem to be very specific to my site of last year while I was with another hosting company and had not started using wordpress/woocommerce at all. example: /gamerules.php is not a page most sites would have so it does not appear to be common or high-value-target url’s.
I would also appreciate any thoughts on this issue.