How to check a site for malicious scripts?

Question

HTML

I installed the UNITE GALLERY module on the site arthata.by on the prestashop engine, after that the problems started...
arthata.by/info/kupit-skinali-v-minske - for example, pop-up windows start to appear on this page and all sorts of nonsense appears on the site .
How to check the site?
I have some strange code displayed in the console

Answer 1

Here is a scanner for viruses , hacker shells, backdoors, spam mailers and other malicious scripts on the hosting.
2ip tool
Dr web
Here is an article how and what

Answer 2

There are scripts to check the site. As an option, download such a script and check the entire site

Answer 3

Try to install an antivirus on the site (you can use any :)).