Found this in the access logs:
84.249.219.233 - - [05/Jun/2014:13:34:49 -0400] "GET /images/404.php?ip=194.100.70.72&port=80&length=20&method=udp HTTP/1.1" 404 47 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36" "-"
84.249.219.233 - - [05/Jun/2014:13:34:49 -0400] "GET /images/404.php?ip=194.100.70.72&port=80&length=20&method=udp HTTP/1.1" 404 47 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36" "-"