How to find and remove a virus that got on the hosting?

Question

HTML

Hello. Need help. One of the client's sites was hacked, and there were about 10 other sites on the hosting. And now all sites are down. Gives error 500, or redirects to advertising sites, here are a few of the

sites this code manually. When I tried to go to the site, it was added again.

How can this virus be removed? Where it can be, it acts on all sites instantly.

I checked the hosting on the built-in antivirus, found nothing, writes cleanly. And other antiviruses showed that it is pure.

Recommend something. Or if anyone can clean the hosting from viruses, write in a personal.

Answer 1

replace the index file to start with the source file
in .htaccess, see what's there

Answer 2

It is necessary to look at how hosting is organized. Perhaps you need to reinstall the operating system with formatting the disk. I hope the original copies of the sites are stored somewhere separately by the owners or in a backup.

Answer 3

The host server is already infected: collect everything you can (if there are no backups) and change hosting. Then - check the files for "infection" using backups and / or aibolit (or this one), and manually - too.

Answer 4

Backup the system with formatting