Core-decrypt 〈UPDATED〉

Look into Quantum-Resistant Algorithms to future-proof core decryption routines.

If the ransomware used an "offline key" (a hardcoded key within the malware), security researchers often release free Decryption Tools to help victims. core-decrypt

Ensure your Bitcoin Core passphrase is stored offline; once the "core" is lost, it cannot be decrypted. once the "core" is lost

When a user enters their password to send a transaction, the software performs a "core-decrypt" of the master key. This master key then unlocks the private keys needed to sign the transaction. core-decrypt

Use services like "ID Ransomware" to see if a public core-decryptor has been released.