STAS ongoing Authentication issues

Hi M8ey 

Do these machines/users ever authenticate?

When the authentication issue happens, what is the logon server set to? Is it 1 of the servers with STAS installed?

Can you post the configuration of your STAS configuration on the servers as well as the XG?

Looking at the logon server that authenticated the user, do you see a logon event created for that user at time of login?

Is this a flat network or are there VLANs and/or L3 switches involved?

Thanks!

Thanks for the comment,

Yes they have been authenticating fine for some time but randomly decided not to anymore.

There are 3 DCs that they can Authenticate to - all have STAS installed and all are in the STAS Group.

I can post many images but keep in mind 200+ users authenticate just fine each day with STAS - so not sure thats where the issue is.

The network does have a L3 switch between the LANs and the XG

If they did authenticate at one stage but now no longer and all other users are working fine, then there must be an issue local on the PC.

If there is no event log for that user, STAS will not send the event to the XG.

If the XG tries to query the PC for user information via STAS and WMI, there should be information that gets populated with that request if the client PC WMI is functioning correctly.

If all else fails, try a new machine with the same user account and IP address and see if it populates the logon.  If that works then you know the issue is local and that you would need to reinstall the system or investigate.

Thanks.

Yep that's about where I am up to.

No clue why just a hand full of these PC's are doing it now for no reason - maybe a Windows 10 1909 update issue....

I will try logging in with another user account and see if its the local PC - although I do see Logon Event logs but get a Logoff right after (even though they are logged on)

Interestingly enough I am not seeing Event ID 4768 but rather Event ID 4624

No clue why this would be though.

Even more digging.

If I open STAS on one of my DCs and go to Advanced and test connectivity the Sophos XG is fine but the two VM DCs cannot communicate with the main DC when testing STAS Agent or Collector 

But I can from the two VM DCs to each other.

I am able to telnet between DCs on Port 5566 and again Windows FW is turned off.

Main DC is on 192.168.1.2

VM 192.168.1.27

Remote 172.16.100.9

VM / Remote talk fine but neither can reach 192.168.1.2 via STAS Testing

I have uninstalled STAS on 192.168.1.2 and reinstalled but no change.

Why would STAS on 192.168.1.2 be upset.

I can test back to the VMs ok from 192.168.1.2 though - both Agent and Collector

You can try reboot that DC.

I have seen it happen before whereby the ephemeral port range used by 1 of the services on Windows takes the port STAS wants to listen on.  

You can check to see if STAS is listening on that port by looking at netstat or using another tool.

Also check to see if there are any other interfaces not connected on the DC.  Sometimes STAS does not bind to the correct interface.

However I believe you not seeing that specific event ID is more than likely your cause.

Have you enabled audit logon/logoff events on the DCs?

KingChris said:

You can try reboot that DC.

Yep on the list for tonight - it also does DHCP so will do after hours.

Will dig a bit more with netstat etc

Yes Logon / Logoff Audit is enabled on all DCs

The first step is, do you see the Users popping up in the STAS Log on STAS Collector? 

There should be entries of "Found User" etc. If not, something is blocking the eventlogs. 

I think the issue is that there are no more Event: 4768 in my DC Security Logs.

Logging is on but no 4768

C:\Users\administrator.ESSFIELDS>auditpol.exe /get /category:*
System audit policy
Category/Subcategory Setting
System
Security System Extension No Auditing
System Integrity No Auditing
IPsec Driver No Auditing
Other System Events No Auditing
Security State Change No Auditing
Logon/Logoff
Logon Success and Failure
Logoff Success and Failure
Account Lockout No Auditing
IPsec Main Mode No Auditing
IPsec Quick Mode No Auditing
IPsec Extended Mode No Auditing
Special Logon No Auditing
Other Logon/Logoff Events Success and Failure
Network Policy Server No Auditing
User / Device Claims No Auditing
Group Membership No Auditing
Object Access
File System No Auditing
Registry No Auditing
Kernel Object No Auditing
SAM No Auditing
Certification Services No Auditing
Application Generated No Auditing
Handle Manipulation No Auditing
File Share No Auditing
Filtering Platform Packet Drop No Auditing
Filtering Platform Connection No Auditing
Other Object Access Events No Auditing
Detailed File Share No Auditing
Removable Storage No Auditing
Central Policy Staging No Auditing
Privilege Use
Non Sensitive Privilege Use No Auditing
Other Privilege Use Events No Auditing
Sensitive Privilege Use No Auditing
Detailed Tracking
Process Creation No Auditing
Process Termination No Auditing
DPAPI Activity No Auditing
RPC Events No Auditing
Plug and Play Events No Auditing
Token Right Adjusted Events No Auditing
Policy Change
Audit Policy Change No Auditing
Authentication Policy Change No Auditing
Authorization Policy Change No Auditing
MPSSVC Rule-Level Policy Change No Auditing
Filtering Platform Policy Change No Auditing
Other Policy Change Events No Auditing
Account Management
Computer Account Management No Auditing
Security Group Management No Auditing
Distribution Group Management No Auditing
Application Group Management No Auditing
Other Account Management Events No Auditing
User Account Management No Auditing
DS Access
Directory Service Access No Auditing
Directory Service Changes No Auditing
Directory Service Replication No Auditing
Detailed Directory Service Replication No Auditing
Account Logon
Kerberos Service Ticket Operations Success and Failure
Other Account Logon Events Success and Failure
Kerberos Authentication Service No Auditing
Credential Validation No Auditing