On vps linux debian sends my smpt access to the left email, how can I disable it?

Question

Debian

There is a vps, it has a site on laravel.
OS: debian.

Noticed a lot of spam from my box. Changed the box. spam is repeated. I noticed that in the sent messages there is a letter where my smpt access is sent to the left email on my behalf. Screenshot:


Changed my email many times. And the procedure itself with sending is repeated.

It is visible somewhere on vps the script got hooked. How to detect it? THIS is despite the fact that mail programs such as postfix are not installed.
The project on laravel also went through everything - zero results.

It is necessary to somehow prohibit sending letters to this left email, or find this script.
Perhaps someone has come across this? What do you suggest?

Answer 1

Thanks to everyone who responded. It turned out that this is a laravel smpt crack.
Maybe it will help someone, solutions:
Reacts when debug = true. You just need to put in env on the server, app_debug = false and that's it.

Answer 2

In fact, there are so many options on Linux where you can put the send script, it's just a damn thing.
But it's trite, to check all crontabs and autoruns (/etc/init.d)
you can also run a recursive search on fewfew
grep -R / "fewfew" as root