Active Directory Authentication

[daddy87]

I have integrated Alfresco with ActiveDirectory using:

authentication.chain=passthru1assthru,ldap-ad1:ldap-ad
ntlm.authentication.sso.enabled=false
passthru.authentication.authenticateCIFS=true
passthru.authentication.guestAccess=false

Logging to Alfresco using AD accounts is successful.

Alfresco has a build in account called admin. I do not have and would not like to have such account in AD.
Event log of AD Controller shows:
Logon Failure:
Reason: Unknown user name or bad password
User Name: admin
Domain: Logon Type: 3
Logon Process: NtLmSsp
Authentication Package: NTLM
Workstation Name: \\KOVAX_47202

There are lots of login failures in AD Controller's log.

How can I stop Alfresco using admin account to authenticate to AD ?

[daddy87]

Update:

All AD accounts properlly authenticate in Domain Controller however there is also a builtin account called ADMIN in Alfresco.
This account periodically tries to authenticate in AD (why ?).

Of course authentication fails for this account (it doesn't exist in AD). There are tons of "logon failures" in Security Log of Domain Controller.
I must avoid those failures.

Could you help me solve this issue ?