DLE redirect virus?

Question

CMS

When entering from a mobile devices from Google search, there is a redirect to the left site. I can't find the virus. Scanned all files for words like android, ios, looked at all mentions of USER_AGENT, header('Location ...'), etc. htaccess is fine. Tell me where and how these redirects can be wired?
P.S. looked at all types of files php, js, tpl. DLE 11.3
Reinstalling or updating the engine is not an option, a lot of edits have already been made in it.