What is error code 0xc0000234?
0xc0000234 – The user account has been automatically locked because too many invalid logon attempts or password change attempts have been requested.
What is Kerberos pre authentication?
Kerberos Pre-Authentication is a security feature which offers protection against password-guessing attacks. The AS request identifies the client to the KDC in Plaintext. If Kerberos Pre-Authentication is enabled, a Timestamp will be encrypted using the user’s password hash as an encryption key.
Should the Krbtgt account be disabled?
Every AD domain has an associated KRBTGT account to encrypt and sign all Kerberos tickets for the domain. The KRBTGT account should stay disabled.
What is error 0xC000006A?
The error code 0xC000006A does means Account logon with misspelled or bad password but not necessarily locked out.
Can Kerberos be disabled?
Disclaimer: Microsoft says that “Disabling Kerberos Pre-Authentication must not be disabled“. Without Kerberos Pre-Authentication a malicious attacker can directly send a dummy request for authentication. The KDC will return an encrypted TGT and the attacker can brute force it offline.
Why are huge numbers of 4771 generating with 0x18?
In our domain after enabling audit we found that huge numbers (around 50k) of Kerberos pre-authentication failed (4771) security failure events are generating in DCs. If any one can explain why this events are generating so frequently. However I found no account lockout has happened. One sample event is as follows.
What does Windows Security log event ID 4771?
If the ticket request fails Windows will either log this event, failure 4771, or 4768 if the problem arose during “pre-authentication”. In Windows Kerberos, password verification takes place during pre-authentication.
How to troubleshoot the Kerberos error 4771 and locked?
Pre-authentication types, ticket options and failure codes are defined in RFC 4120. If the ticket was malformed or damaged during transit and could not be decrypted, then many fields in this event might not be present. Now we can see an IP address of the server who send request.
Where can I find a lockout in ALTools?
You’re able to hunt down a lockout with Altools lockoutstaus: http://www.microsoft.com/downloads/en/details.aspx?FamilyId=7AF2E69C-91F3-4E63-8629-B999ADDE0B9E&displaylang=en Then track down the event that you’ve posted. In normal circumstances you would find this event on PDC as last,due to the logic how the account is verified.
