Some kind of left POST requests in the logs. Perhaps some script is running?

Question

Yii

The site was transferred to a new self-written cms, made error logs to come, after which I began to notice strange post requests to the main page of the site.

2016-11-21 08:43:10
[138.201.171.213][-][b2kubb61490amjud1bntesfg11][error][yii\web\HttpException:400]
yii\web\BadRequestHttpException: Не удалось
проверить переданные данные. in
/var/www/vendor/yiisoft/yii2/web/Controller.php:112
Stack trace:
#0 /var/www/components/Controller.php(108):
yii\web\Controller->beforeAction(Object(yii\base\InlineAction))
#1 /var/www/vendor/yiisoft/yii2/base/Controller.php(154):
shop\components\Controller->beforeAction(Object(yii\base\InlineAction))
#2 /var/www/vendor/yiisoft/yii2/base/Module.php(524):
yii\base\Controller->runAction('index', Array)
#3 /var/www/vendor/yiisoft/yii2/web/Application.php(102):
yii\base\Module->runAction('', Array)
#4 /var/www/vendor/yiisoft/yii2/base/Application.php(373):
yii\web\Application->handleRequest(Object(yii\web\Request))
#5 /var/www/web/index.php(31): yii\base\Application->run()
#6 {main}
2016-11-21 08:43:10
[138.201.171.213][-][b2kubb61490amjud1bntesfg11][info][application]
$_POST = [
    'url' => 'http://www.animestore***/'
    'timeout' => '10'
]

$_SESSION = [
    '__flash' => []
]

$_SERVER = [
    'USER' => 'www-data'
    'HOME' => '/var/www'
    'HTTP_CONTENT_TYPE' => 'multipart/form-data;
boundary=----------------------------2e22fb8a1b99'
    'HTTP_EXPECT' => '100-continue'
    'HTTP_CONTENT_LENGTH' => '265'
    'HTTP_ACCEPT' => '*/*'
    'HTTP_HOST' => 'nyaki.ru'
    'HTTP_USER_AGENT' => 'Mozilla/5.0 (X11; U; Linux i686; ru;
rv:1.9.0.5) Gecko/2008121622 Ubuntu/8.10 (intrepid) Firefox/3.0.5'
    'SCRIPT_FILENAME' => '/var/www/web/index.php'
    'REDIRECT_STATUS' => '200'
    'SERVER_NAME' => 'nyaki.ru'
    'SERVER_PORT' => '80'
    'SERVER_ADDR' => '62.76.178.246'
    'REMOTE_PORT' => '57974'
    'REMOTE_ADDR' => '138.201.171.213'
    'SERVER_SOFTWARE' => 'nginx/1.10.1'
    'GATEWAY_INTERFACE' => 'CGI/1.1'
    'REQUEST_SCHEME' => 'http'
    'SERVER_PROTOCOL' => 'HTTP/1.1'
    'DOCUMENT_ROOT' => '/var/www/web'
    'DOCUMENT_URI' => '/index.php'
    'REQUEST_URI' => '/'
    'SCRIPT_NAME' => '/index.php'
    'CONTENT_LENGTH' => '265'
    'CONTENT_TYPE' => 'multipart/form-data;
boundary=----------------------------2e22fb8a1b99'
    'REQUEST_METHOD' => 'POST'
    'QUERY_STRING' => ''
    'FCGI_ROLE' => 'RESPONDER'
    'PHP_SELF' => '/index.php'
    'REQUEST_TIME_FLOAT' => 1479717790.2041
    'REQUEST_TIME' => 1479717790
]

All anything, but it occurs periodically. The most confusing thing is
'timeout' => '10'
Perhaps someone is trying to lower the site in search engines due to pov. factors? But these are only assumptions. What could it be?

Answer 1

Show the log in full. It is not clear with what data the client is breaking. What is the logic of hiding part of the urls, but for example

'SERVER_NAME' => 'nyaki.ru'

leave??!

Answer 2

Maybe it's spam? Maybe earlier there was a comment form on the main page or something else. They are trying to spam the site.
Then why post and not get requests?