I have just seen a new series of error in the /var/log/apache2/error.log
[Thu May 07 17:12:35.433760 2015] [:error] [pid 3488] [client 190.79.132.215:51660] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:38.066293 2015] [:error] [pid 3471] [client 190.79.132.215:51679] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:43.523091 2015] [:error] [pid 3474] [client 190.204.156.103:59542] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:45.213665 2015] [:error] [pid 3451] [client 190.204.156.103:59568] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:50.660274 2015] [:error] [pid 3472] [client 190.204.156.103:59592] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:51.354739 2015] [:error] [pid 3473] [client 82.8.22.23:49205] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:51.512948 2015] [:error] [pid 3446] [client 82.8.22.23:49206] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:51.669047 2015] [:error] [pid 3488] [client 82.8.22.23:49207] script '/var/www/html/r.php' not found or unable to stat
[Thu May 07 17:12:51.838961 2015] [:error] [pid 3471] [client 82.8.22.23:49208] script '/var/www/html/r.php' not found or unable to stat
r.php
doesn't exist.
This server is running Ubuntu 14.04 in a LAMP setup.
I have never seen this sort of attack before, should i be concerned or securing my system in any way for them?