SMB login attempt - server initiated

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L4 Transporter

SMB login attempt - server initiated

Is it normal for DC trying o reach systems on 445 and 139

I get bruteforce alerts for only 1 system, even though DC is trying to reach almost every system in that zone on 445/smb

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Accepted Solutions
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L5 Sessionator

Re: SMB login attempt - server initiated

If you disable user identification on the public wifi zone you will lose User-ID visibility within that zone but that won't necessarily stop the agent from attempting to enumerate systems within that zone.  You can either implement a security policy rule to deny/drop User-ID agent traffic to this zone or you could simply exempt the IP address for this system within the IP exemption list within the User-ID agent as seen here.

 

https://live.paloaltonetworks.com/t5/Management-Articles/How-the-User-ID-Agent-Include-Exclude-List-...

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All Replies
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L5 Sessionator

Re: SMB login attempt - server initiated

The PA UserAgent (user-id agent I assume) appears to be running on this DC.  Is the agent performing enumeration of user to IP mappings from this DC?  Do you have WMI probing enabled?  That could explain the behavior you are seeing.

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L4 Transporter

Re: SMB login attempt - server initiated

Yes PA user agent is installed

WMI probes not enabled.

Highlighted
L5 Sessionator

Re: SMB login attempt - server initiated

Is the "victim" host a domain controller or other Windows server which the Agent would attempt to access to enumerate users?  I suspect this is normal behavior yet there could be underlying login issues between the DC and 10.4.190.66 (victim).  If 10.4.190.66 is not needed for enumeration purposes you could add it to the IP exemption list within the Agent.

Highlighted
L4 Transporter

Re: SMB login attempt - server initiated

Victim system is in publicly accessible wifi, and most likely seems to be windows.

Would disabling user identification on this zone stop this, or should i disable this traffic from DC's into this zone.

Highlighted
L5 Sessionator

Re: SMB login attempt - server initiated

If you disable user identification on the public wifi zone you will lose User-ID visibility within that zone but that won't necessarily stop the agent from attempting to enumerate systems within that zone.  You can either implement a security policy rule to deny/drop User-ID agent traffic to this zone or you could simply exempt the IP address for this system within the IP exemption list within the User-ID agent as seen here.

 

https://live.paloaltonetworks.com/t5/Management-Articles/How-the-User-ID-Agent-Include-Exclude-List-...

View solution in original post

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