How Do I Fix This Issue After Hacked Website?

I recently recovered after a hacked website, and when I run my WordFence scan, this is an issue that this plugin found. It says:

Your DNS records have changed

Old DNS records:
New DNS records: www."mywebsite".com points to "mywebsite".com - (My website is called differently but I do this for safety reasons)

Severity: Warning
Status New

We have detected a change in the CNAME records of your DNS configuration for the domain www.garfieldstips.com. A CNAME record is an alias that is used to point a domain name to another domain name. For example foo.example.com can point to bar.example.com which then points to an IP address of 10.1.1.1. A change in your DNS records may indicate that a hacker has hacked into your DNS administration system and has pointed your email or website to their own server for malicious purposes. It could also indicate that your domain has expired. If you made this change yourself you can mark it 'resolved' and safely ignore it.

Here is an imgur image of the issue:
https://imgur.com/a/k3NFG

Does anyone know how can I fix this issue?
Thanks!