RYUK ransomware, notoriously known for attacking corporations and large businesses, uses military grade encryption standards of AES 256 bit and RAS 1024 bit. Without the decryption key, it is impossible to decrypt large amounts of data. To get back up online in the shortest amount of time, the only resort left with victims is to pay the ransom amount.
The method of recovering data by restoring it from backups takes as much as up to weeks which isn’t viable for many corporations due to the costly business downtime.