4707(S): A trust to a ___domain was removed.

Subcategory: Audit Authentication Policy Change

Event Description:

This event generates when a ___domain trust was removed.

This event is generated only on ___domain controllers.

Note  For recommendations, see Security Monitoring Recommendations for this event.

Event XML:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
 <Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" /> 
 <EventID>4707</EventID> 
 <Version>0</Version> 
 <Level>0</Level> 
 <Task>13569</Task> 
 <Opcode>0</Opcode> 
 <Keywords>0x8020000000000000</Keywords> 
 <TimeCreated SystemTime="2015-10-01T20:41:13.080444700Z" /> 
 <EventRecordID>1049754</EventRecordID> 
 <Correlation /> 
 <Execution ProcessID="500" ThreadID="580" /> 
 <Channel>Security</Channel> 
 <Computer>DC01.contoso.local</Computer> 
 <Security /> 
 </System>
- <EventData>
 <Data Name="DomainName">FABRIKAM</Data> 
 <Data Name="DomainSid">S-1-5-21-2226861337-2836268956-2433141405</Data> 
 <Data Name="SubjectUserSid">S-1-5-21-3457937927-2839227994-823803824-1104</Data> 
 <Data Name="SubjectUserName">dadmin</Data> 
 <Data Name="SubjectDomainName">CONTOSO</Data> 
 <Data Name="SubjectLogonId">0x3e99d6</Data> 
 </EventData>
 </Event>

Required Server Roles: Active Directory ___domain controller.

Minimum OS Version: Windows Server 2008.

Event Versions: 0.

Field Descriptions:

Subject:

• Security ID [Type = SID]: SID of account that requested the “remove ___domain trust” operation. Event Viewer automatically tries to resolve SIDs and show the account name. If the SID cannot be resolved, you will see the source data in the event.

Note  A security identifier (SID) is a unique value of variable length used to identify a trustee (security principal). Each account has a unique SID that is issued by an authority, such as an Active Directory ___domain controller, and stored in a security database. Each time a user logs on, the system retrieves the SID for that user from the database and places it in the access token for that user. The system uses the SID in the access token to identify the user in all subsequent interactions with Windows security. When a SID has been used as the unique identifier for a user or group, it cannot ever be used again to identify another user or group. For more information about SIDs, see Security identifiers.

• Account Name [Type = UnicodeString]: the name of the account that requested the “remove ___domain trust” operation.

• Account Domain [Type = UnicodeString]: subject’s ___domain or computer name. Formats vary, and include the following:

  • Domain NETBIOS name example: CONTOSO

  • Lowercase full ___domain name: contoso.local

  • Uppercase full ___domain name: CONTOSO.LOCAL

  • For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.

  • For local user accounts, this field will contain the name of the computer or device that this account belongs to, for example: “Win81”.

• Logon ID [Type = HexInt64]: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”

Domain Information:

• Domain Name [Type = UnicodeString]: the name of removed trusted ___domain.

• Domain ID [Type = SID]: SID of removed trusted ___domain. Event Viewer automatically tries to resolve SIDs and show the account name. If the SID cannot be resolved, you will see the source data in the event.

Security Monitoring Recommendations

For 4707(S): A trust to a ___domain was removed.

• Any changes related to Active Directory ___domain trusts (especially trust removal) must be monitored and alerts should be triggered. If this change was not planned, investigate the reason for the change.