security issue

hello, we have our website infomateknoloji.com was created under www.remarpro.com. the site was hacked and started to be directed to other sites. We have been informed that the site might have been created with an unlicenced theme. So, we have purhased gigas theme and created infoma.biz with gigas under www.remarpro.com. now, we face the same problem with our new site. Hosting company checked thd situation and informed us the following codes contains functions.php
https://prnt.sc/6jaqjJMu1hfz

They informed us these are not codes connected to the theme. They crack and warez type of codes

So , as we are sure now that the theme is licenced, why this pronlem occurs and how we could solve it.
thank you in advance.

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