CMS Wordpress: how to remove malicious code?

Question

Malware

Hello! Malicious code has been uploaded to our site. and it is everywhere both in the admin panel and on the site itself. Maybe someone has come across this? How to solve such a problem? Deleted it but it reappears. The site reloaded all the files, but everything appears again.

<img src="//interestourflash.info/acnt?_=1573599632612&amp;did=21&amp;tag=ru&amp;r=http%253A%252F%252Fnewsmood.pp.ua%252Fwp-admin%252Fpost.php%253Fpost%253D18813%2526action%253Dedit&amp;ua=Mozilla%2F5.0%20(Windows%20NT%206.1%3B%20rv%3A70.0)%20Gecko%2F20100101%20Firefox%2F70.0&amp;aac=&amp;if=1&amp;uid=1573577567&amp;cid=2&amp;v=430" />