my computer was hacked and someone could have a look upon all my private files including my website details … how can I change my website certificate keys
# revoke cert, do this for every site you have
certbot revoke --cert-path /etc/letsencrypt/live/"domain"/cert.pem
# revoke account key and create new one
certbot unregister; certbot register
# get a new cert
certbot renew --force
Note that you might also want to reinstall (reprovision) your server image—if the attacker wanted to be able to get back in in the future, he or she could have left some kind of back door, for example by replacing some of the software on the system with a corrupted version.