我正在运行 ubuntu 16.04，突然在过去的两天里我的服务器基本上处于停滞状态，我已经升级了所有内容并清理了我的错误日志。
我重启了服务器，大约 5 分钟后它又停止了。检查进程，没有一个进程超过 CPU 的 10%。
检查错误日志时，我发现只有以下条目对我来说很奇怪。
[Tue Mar 12 13:21:50.398619 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/9678.php' not found or unable to stat
[Tue Mar 12 13:21:50.509673 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/wc.php' not found or unable to stat
[Tue Mar 12 13:21:50.630470 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/xx.php' not found or unable to stat
[Tue Mar 12 13:21:50.827904 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/s.php' not found or unable to stat
[Tue Mar 12 13:21:51.002760 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/w.php' not found or unable to stat
[Tue Mar 12 13:21:51.179510 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/sheep.php' not found or unable to stat
[Tue Mar 12 13:21:51.411913 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/qaq.php' not found or unable to stat
[Tue Mar 12 13:21:51.649432 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/db.init.php' not found or unable to stat
[Tue Mar 12 13:21:51.967375 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/db_session.init.php' not found or unable to stat
[Tue Mar 12 13:21:52.160257 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/db__.init.php' not found or unable to stat
[Tue Mar 12 13:21:52.536444 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/wp-admins.php' not found or unable to stat
[Tue Mar 12 13:21:52.765769 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/m.php' not found or unable to stat
[Tue Mar 12 13:21:53.076742 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/099.php' not found or unable to stat
[Tue Mar 12 13:21:53.329621 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/_404.php' not found or unable to stat
[Tue Mar 12 13:21:53.588267 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/Alarg53.php' not found or unable to stat
[Tue Mar 12 13:21:53.823077 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/lapan.php' not found or unable to stat
[Tue Mar 12 13:21:53.918564 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/p34ky1337.php' not found or unable to stat
[Tue Mar 12 13:21:54.081972 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/pk1914.php' not found or unable to stat
[Tue Mar 12 13:21:54.179365 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/sllolx.php' not found or unable to stat
[Tue Mar 12 13:21:54.290338 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/Skri.php' not found or unable to stat
[Tue Mar 12 13:21:54.529489 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/db_dataml.php' not found or unable to stat
[Tue Mar 12 13:21:54.755711 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/db_desql.php' not found or unable to stat
[Tue Mar 12 13:21:54.850979 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/mx.php' not found or unable to stat
[Tue Mar 12 13:21:55.118621 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/wshell.php' not found or unable to stat
[Tue Mar 12 13:21:55.368692 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/xshell.php' not found or unable to stat
[Tue Mar 12 13:21:55.470548 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/qq.php' not found or unable to stat
[Tue Mar 12 13:21:55.570334 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/conflg.php' not found or unable to stat
[Tue Mar 12 13:21:55.670565 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/conflg.php' not found or unable to stat
[Tue Mar 12 13:21:55.786180 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/lindex.php' not found or unable to stat
[Tue Mar 12 13:21:55.907402 2019] [:error] [pid 8974] [client 45.113.70.238:41364] script '/var/www/files/phpstudy.php' not found or unable to stat
[Tue Mar 12 13:21:55.993093 2019] [mpm_prefork:error] [pid 8702] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting