Toor is an alternative superuser account (toor is root spelt backwards) in UNIX like Operating Systems, mostly in BSD family of Operating Systems.

The Bourne-Again Super-user. An alternate account with UID of 0, created on Unix machines where the root user has an inconvenient choice of shell.

toor:*:0:0::0:0:Bourne-again Superuser:/root:

Some people use toor for day-to-day root tasks with a non-standard shell, leaving root, with a standard shell, for single user mode or emergencies. By default you cannot log in using toor as it does not have a password, so log in as root and set a password for toor if you want to use it.

Previously, it was created when the bash shell was installed, but now it is created by default. It is intended to be used with a non-standard shell so you do not have to change root's default shell. This is important as shells which are not part of the base distribution (for example a shell installed from ports or packages) are likely to be installed in /usr/local/bin which, by default, resides on a different filesystem. If root's shell is located in /usr/local/bin and /usr (or whatever filesystem contains /usr/local/bin) is not mounted for some reason, root will not be able to log in to fix a problem (although if you reboot into single user mode you will be prompted for the path to a shell).

It is also the default superuser in few Operating Systems like NetBSD.

Sometimes the account 'toor' has no password set and is not disbled. An attacker may use it to gain further privileges on this system, so set a password for this account or disable it.