https://www.bleepingcomputer.com/news/security/new-ransomware-decryptor-recovers-data-from-partially-encrypted-files/

A new 'White Phoenix' ransomware decryptor allows victims to partially recover files encrypted by ransomware strains that use intermittent encryption.

Intermittent encryption is a strategy employed by several ransomware groups that alternates between encrypting and not encrypting chunks of data. This method allows a file to be encrypted much faster while still leaving the data unusable by the victim.