Need help to fix WordPress hacked site issue

[naviinju]

Dear all,

am facing major issue in my WordPress websites, I'm having 30 WordPress websites in a separate server used as shared,
for a few days, all sites showing 503 error due to high request and reached limits,
then I realize and found malicious codes in every domain directory ( i have shared the file link below )
need a solution to fix it as soon as possible am now hopeless and please someone helps to find it out.

malicious files.zip

drive.google.com

 

[dareal90]

Guess ur sites was first DDOSed before penetration, I can fix this one by one , but comes with charges.

 

[ahezkhan]

PM me ill help you, muft if possible

 

[funguy]

You must delete all malicious files manually and harden server security.

 

[jackal]

delete all malicious files, if you have backup it will be eazy.Else it is time consuming job.If any support needed pls update

 

[harry26]

If you can DM me your login details I'll take a look and also will fix it + will make sure to add enough security to precent this from happening in future.