Final answer:
A golden ticket is the type of ticket that attackers issue themselves without an expiration date.
Step-by-step explanation:
The type of ticket that attackers issue themselves without an expiration date is called a golden ticket. A golden ticket is a forged TGT (Ticket-Granting Ticket) that allows an attacker to impersonate any user in the domain. It is created by compromising the administrative credentials of the Kerberos server and is often issued with an extended expiration time.