I run a publicly accessible web service, and get this stuff all the time.

My service happens to be fronted by nginx, so over time I accumulate config to match these and drop connections and drop from the logs entirely:

  location /wp-admin {
    access_log off;
    log_not_found off;
    return 444;
  }

(444 is a nonstandard error code that tells nginx to just close the connection, don't respond at all; if you want to be more mischievous you could return 301 "https://nsa.gov")