Good morning everyone. I have a big problem.

I have a number of domains with an internet service provider. Normally only one process is active. The process is this one:

CROND
/bin/bash -c /usr/bin/php /home/bs1pcgbn/mysite/api/cron.php >/dev/null 2>&1 0% 1
/opt/cpanel/ea-php56/root/usr/bin/php-cgi /home/bs1pcgbn/mysite/api/cron.php

The Physical Memory used is normally under 300 M.

One day the processes started to increase suddenly reaching more than 50 contemporary processes. The Physical Memory also increase to reach 934 M.

At this point it became impossible to reach the domains.

The increase in processes is due ... to the same process. Let me explain. As I wrote, before the increase, the only process was as follows:

CROND
/bin/bash -c /usr/bin/php /home/bs1pcgbn/mysite/api/cron.php >/dev/null 2>&1 0% 1
/opt/cpanel/ea-php56/root/usr/bin/php-cgi /home/bs1pcgbn/mysite/api/cron.php

Subsequently, this process, without any intervention, is replicated several times. If I take a snapshot, the list is full of this process repeated several times

The provider states that I need to check the installed plugins. But I didn't install any plugins .... Can you help me?

How is this process executed? If you manually run this, does it replicate?
Instead of /dev/null, how about redirect to an actual file and see if it gives you anything useful?

Thanks for your reply.
At the moment I have no active cron but this process continues to operate. I deleted all site-related installations but nothing changed. If you look at the attachments, in the first attachment (picture 1) there is a photograph of when the situation has changed (10 of aprile about 13:00 AM Italy time). In the second picture (picture 2) the indicated process. Before 10 of april 2019 there were only 1 process active. Now I have a lot of the same process

Attached Thumbnails

   

The provider says it must be the fault of some plugins I have installed. But I didn't install any plugins. And all domains are unattainable at the moment.
BTW, I can't modify this process because ... it doesn't exist. This cron does not exist in all directories ... Unfortunately I don't have access to the machine (only the provider can do it)

Please run
to see if the php script runs other processes that are hung.
Also helpful, run an strace on cron
and see what it does. Unfortunately cron does other jobs, so the strace might also follow some of these jobs.
Ctrl-c will stop the strace (if not then try Ctrl-z and "pkill -9 -x strace").