Forged tickets

Silver and Golden tickets are forged Kerberos tickets that can be used with pass-the-ticket to access services in an Active Directory domain.

When one of krbtgt's Kerberos keys is known, a golden ticket attack can be conducted to keep privileged access until that account's password is changed.
Let service be an account in charge of various services indicated in its ServicePrincipalNames attribute, when one of service's Kerberos keys is known, a silver ticket attack can be conducted to keep privileged access to those managed services until that account's password is changed.