Since almost all cases of secret.key coming up in the last weeks were that:
If you are trying to restore a wallet that gives you access to 1.5 million ADA on the addresses https://adastat.net/addresses/DdzFFzCqrhtDG8CnukNLfmDUyixQNgn7a1sEMunMfVXuqCnq7x7KkwyCvK88VSe9UBWxVvWUzYUD2cXYdWLkqn1fQPFqRCgbfWrA1uBP and https://adastat.net/addresses/DdzFFzCqrhsmiiQJ9QCqgRz6jisU688V2mSnJQ2R8Hwz2gS6ezHoawJkiE9VhkHNCHCjz2AZ4RJ9cPy2Raq9RkGYacfsm7H4owtfQvo2, then just forget it!
Dozens of people have been hoaxed by that in the last years. All secret.key files going around for that were broken beyond repair and it’s very likely that those wallets are lost for good.