What's going on with the server? Attacks?

Question

Nginx

Hello, I decided to restart nginx, then I went to look at the logs, and then I began to understand that some strange nonsense was going on with the server.
Per second, 10-30 KB are added to the error.log file, this is what I saw in it:

2018/04/25 21:17:00 [error] 1586#1586: *7 "/var/www/html/telegraph/tot2/PC-LOFT10_W10015063.F042C2276277C2D0D788BA9CFF25EBAC/14/conf/2/0/index.php" is not found (2: No such file or directory), client: 104.193.30.21, server: samp-telegraph.org, request: "GET /tot2/PC-LOFT10_W10015063.F042C2276277C2D0D788BA9CFF25EBAC/14/conf/2/0/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:01 [error] 1586#1586: *8 "/var/www/html/telegraph/jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 166.90.119.2, server: samp-telegraph.org, request: "POST /jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:02 [error] 1586#1586: *9 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:02 [error] 1586#1586: *8 "/var/www/html/telegraph/jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 166.90.119.2, server: samp-telegraph.org, request: "POST /jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:03 [error] 1586#1586: *9 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:04 [error] 1586#1586: *8 "/var/www/html/telegraph/jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 166.90.119.2, server: samp-telegraph.org, request: "POST /jim168/USNASDT20135_W617601.A2027912657215733591E8A485146040/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:04 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:04 [error] 1586#1586: *9 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/PING/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:05 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:06 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:06 [error] 1586#1586: *10 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:07 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:07 [error] 1586#1586: *10 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:08 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:09 [error] 1586#1586: *10 "/var/www/html/telegraph/ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/index.php" is not found (2: No such file or directory), client: 79.147.41.106, server: samp-telegraph.org, request: "POST /ser0322/MARIAPC_W10016299.741F223F5A53A4604E2ED6CAE5BC0E28/64/injectDll/DPST/browser/ HTTP/2.0", host: "185.228.232.139"
2018/04/25 21:17:09 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:12 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:13 [error] 1586#1586: *11 "/var/www/html/telegraph/del7/RFA-PBS03_W617601.C96EB63EBCE7D9CDB058BC8A75E4A13A/5/spk/index.php" is not found (2: No such file or directory), client: 171.33.197.142, server: samp-telegraph.org, request: "GET /del7/RFA-PBS03_W617601.C96EB63EBCE7D9CDB058BC8A75E4A13A/5/spk/ HTTP/1.1", host: "185.228.232.139"
2018/04/25 21:17:14 [error] 1586#1586: *1 "/var/www/html/telegraph/lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/index.php" is not found (2: No such file or directory), client: 66.60.240.3, server: samp-telegraph.org, request: "POST /lib1/CWDZ0R1_W617601.CC3A2D228A37150BB7C0E4BD5124D3C2/64/injectDll/PING/browser/ HTTP/1.1", host: "185.228.232.139"

As I understand it, POST requests are sent to my server from the bot?
I would believe that this is DDoS, but:
1) There is no load on the server, as an error page is displayed, and the monitoring shows that the load is 1-3%, and then, this is from me, since I decided to test MySQL through PHP
2) About 10 people know about this server, domain, who don't care about it
. And who needs it at 5 am?
I'm sitting here, I don't know what to do :/

Answer 1

Hooray, congratulations, now you have learned that there are crawler bots on the Internet.
The easiest option is to do nothing at all. There can be dozens or hundreds of such bots per day, they do not give a special load, and the fight against them is practically meaningless, because. addresses change.