On a pentest we found that a kerberos ticket under account name administrator was cached on one of the SQL database server which allowed us to steal the ticket, pass-the-ticket and log onto the domain controller. The logon type was remoteinteractive which suggests that a user from SQLDB01 made a RDP session to DC01. In terms of recommendation, I believe restricted admin mode does not protect against this attack as this protection just forces kerberos ticket to default.
- What other recommendations are there?
- Use credential guard to protect against dumping of kerberos tickets (?)
- What is the correct/secure way to log onto the DC? I assume a jumpbox?