> The threat actor was also able to copy a backup of customer vault data from the encrypted storage container which is stored in a proprietary binary format that *contains both unencrypted data, such as website URLs,* as well as fully-encrypted sensitive fields such as website usernames and passwords, secure notes, and form-filled data
That's real bad - think blackmail material for important people.
That definitely cannot be true since they were storing URLs in vaults unencrypted. Seems like a class action lawsuit waiting to happen.
https://www.lastpass.com/security/zero-knowledge-security