Every now and then I remember to look at my web site's traffic. Every month my site produces a few hundred "URL not found" errors, and almost all of them are related to Wordpress -- wp-login.php, xmlrpc.php, and wlwmanifest.xml (tried at a bunch of entry points, each exactly 30 times in the last 30 days, presumably a daily probe).

I don't run Wordpress -- never have. But I guess it's popular enough, and has bugs or security holes, that people find it worthwhile to send their bots to look for it on every web site they can find?