I was checking the access logs for my site and found several of the following requests (site name, IP addresses, and other general info removed for clarity):
IP - - [Date/time] "POST / HTTP/1.0" 200 1815 "http://SITENAME.com//wp-admin/" "Browser"
IP - - [Date/time] "POST / HTTP/1.0" 200 1815 "http://SITENAME.com/wp-admin/" "Browser"
IP - - [Date/time] "POST / HTTP/1.0" 200 2761 - "Browser"
I don't have Wordpress installed and some of the referer URLs don't even seem valid (eg, "http://SITENAME.com//wp-admin"), but many have a successful status code (200) and data was transferred (seems to always be either 1,815 or 2,761 bytes).
I'm not concerned about someone accessing my site, I know odd access requests are normal and no strange files have appeared in my site directory. The requests are often followed by several failed attempts to access more specific Wordpress files.
What are they checking for and why is the check able to succeed?