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4741(S): A computer account was created.

  • Artykuł

Event 4741 illustration

Subcategory: Audit Computer Account Management

Event Description:

This event generates every time a new computer object is created.

This event generates 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>4741</EventID> 
 <Version>0</Version> 
 <Level>0</Level> 
 <Task>13825</Task> 
 <Opcode>0</Opcode> 
 <Keywords>0x8020000000000000</Keywords> 
 <TimeCreated SystemTime="2015-08-12T18:41:39.201898100Z" /> 
 <EventRecordID>170254</EventRecordID> 
 <Correlation /> 
 <Execution ProcessID="520" ThreadID="1096" /> 
 <Channel>Security</Channel> 
 <Computer>DC01.contoso.local</Computer> 
 <Security /> 
 </System>
- <EventData>
 <Data Name="TargetUserName">WIN81$</Data> 
 <Data Name="TargetDomainName">CONTOSO</Data> 
 <Data Name="TargetSid">S-1-5-21-3457937927-2839227994-823803824-6116</Data> 
 <Data Name="SubjectUserSid">S-1-5-21-3457937927-2839227994-823803824-1104</Data> 
 <Data Name="SubjectUserName">dadmin</Data> 
 <Data Name="SubjectDomainName">CONTOSO</Data> 
 <Data Name="SubjectLogonId">0xc88b2</Data> 
 <Data Name="PrivilegeList">-</Data> 
 <Data Name="SamAccountName">WIN81$</Data> 
 <Data Name="DisplayName">-</Data> 
 <Data Name="UserPrincipalName">-</Data> 
 <Data Name="HomeDirectory">-</Data> 
 <Data Name="HomePath">-</Data> 
 <Data Name="ScriptPath">-</Data> 
 <Data Name="ProfilePath">-</Data> 
 <Data Name="UserWorkstations">-</Data> 
 <Data Name="PasswordLastSet">8/12/2015 11:41:39 AM</Data> 
 <Data Name="AccountExpires">%%1794</Data> 
 <Data Name="PrimaryGroupId">515</Data> 
 <Data Name="AllowedToDelegateTo">-</Data> 
 <Data Name="OldUacValue">0x0</Data> 
 <Data Name="NewUacValue">0x80</Data> 
 <Data Name="UserAccountControl">%%2087</Data> 
 <Data Name="UserParameters">-</Data> 
 <Data Name="SidHistory">-</Data> 
 <Data Name="LogonHours">%%1793</Data> 
 <Data Name="DnsHostName">Win81.contoso.local</Data> 
 <Data Name="ServicePrincipalNames">HOST/Win81.contoso.local RestrictedKrbHost/Win81.contoso.local HOST/WIN81 RestrictedKrbHost/WIN81</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 “create Computer object” 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 “create Computer object” operation.

  • Account Domain [Type = UnicodeString]: subject’s domain 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”.

  • 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.”

New Computer Account:

  • Security ID [Type = SID]: SID of created computer account. 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.

  • Account Name [Type = UnicodeString]: the name of the computer account that was created. For example: WIN81$

  • Account Domain [Type = UnicodeString]: domain name of created computer account. Formats vary, and include the following:

    • Domain NETBIOS name example: CONTOSO

    • Lowercase full domain name: contoso.local

    • Uppercase full domain name: CONTOSO.LOCAL

Attributes:

  • SAM Account Name [Type = UnicodeString]: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.

  • Display Name [Type = UnicodeString]: the value of displayName attribute of new computer object. It is a name displayed in the address book for a particular account (typically – user account). This is usually the combination of the user's first name, middle initial, and last name. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • User Principal Name [Type = UnicodeString]: internet-style login name for the account, based on the Internet standard RFC 822. By convention this should map to the account's email name. This parameter contains the value of userPrincipalName attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Home Directory [Type = UnicodeString]: user's home directory. If homeDrive attribute is set and specifies a drive letter, homeDirectory should be a UNC path. The path must be a network UNC of the form \\Server\Share\Directory. This parameter contains the value of homeDirectory attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Home Drive [Type = UnicodeString]: specifies the drive letter to which to map the UNC path specified by homeDirectory account’s attribute. The drive letter must be specified in the form DRIVE\_LETTER:. For example – H:. This parameter contains the value of homeDrive attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Script Path [Type = UnicodeString]: specifies the path of the account's logon script. This parameter contains the value of scriptPath attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Profile Path [Type = UnicodeString]: specifies a path to the account's profile. This value can be a null string, a local absolute path, or a UNC path. This parameter contains the value of profilePath attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • User Workstations [Type = UnicodeString]: contains the list of NetBIOS or DNS names of the computers from which the user can logon. Each computer name is separated by a comma. The name of a computer is the sAMAccountName property of a computer object. This parameter contains the value of userWorkstations attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Password Last Set [Type = UnicodeString]: last time the account’s password was modified. For manually created computer account, using Active Directory Users and Computers snap-in, this field typically has value <never>. For computer account created during standard domain join procedure this field will contains time when computer object was created, because password creates during domain join procedure. For example: 8/12/2015 11:41:39 AM. This parameter contains the value of pwdLastSet attribute of new computer object.

  • Account Expires [Type = UnicodeString]: the date when the account expires. This parameter contains the value of accountExpires attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. This parameter might not be captured in the event, and in that case appears as -.

  • Primary Group ID [Type = UnicodeString]: Relative Identifier (RID) of computer’s object primary group.

Note

Relative identifier (RID) is a variable length number that is assigned to objects at creation and becomes part of the object's Security Identifier (SID) that uniquely identifies an account or group within a domain.

Typically, Primary Group field for new computer accounts has the following values:

  • 516 (Domain Controllers) – for domain controllers.

  • 521 (Read-only Domain Controllers) – for read-only domain controllers (RODC).

  • 515 (Domain Computers) – for member servers and workstations.

    See the well-known security principals for more information. This parameter contains the value of primaryGroupID attribute of new computer object.

  • AllowedToDelegateTo [Type = UnicodeString]: the list of SPNs to which this account can present delegated credentials. Can be changed using Active Directory Users and Computers management console in Delegation tab of computer account. Typically it is set to - for new computer objects. This parameter contains the value of AllowedToDelegateTo attribute of new computer object. See description of AllowedToDelegateTo field for “4742: A computer account was changed” event for more details.

Note

Service Principal Name (SPN) is the name by which a client uniquely identifies an instance of a service. If you install multiple instances of a service on computers throughout a forest, each instance must have its own SPN. A given service instance can have multiple SPNs if there are multiple names that clients might use for authentication. For example, an SPN always includes the name of the host computer on which the service instance is running, so a service instance might register an SPN for each name or alias of its host.

  • Old UAC Value [Type = UnicodeString]: is always “0x0” for new accounts.

  • New UAC Value [Type = UnicodeString]: specifies flags that control password, lockout, disable/enable, script, and other behavior for the user or computer account. This parameter contains the value of the SAM implementation of account flags (definition differs from userAccountControl in AD). For a list of account flags you may see here, refer to [MS-SAMR]: USER_ACCOUNT Codes.

  • User Parameters [Type = UnicodeString]: if you change any setting using Active Directory Users and Computers management console in Dial-in tab of computer’s account properties, then you will see <value changed, but not displayed> in this field in “4742(S): A computer account was changed.” This parameter might not be captured in the event, and in that case appears as -.

  • SID History [Type = UnicodeString]: contains previous SIDs used for the object if the object was moved from another domain. Whenever an object is moved from one domain to another, a new SID is created and becomes the objectSID. The previous SID is added to the sIDHistory property. This parameter contains the value of sIDHistory attribute of new computer object. This parameter might not be captured in the event, and in that case appears as -.

  • Logon Hours [Type = UnicodeString]: hours that the account is allowed to logon to the domain. The value of logonHours attribute of new computer object. For computer objects, it is optional, and typically is not set. You can change this attribute by using Active Directory Users and Computers, or through a script, for example. You will see <value not set> value for new created computer accounts in event 4741.

  • DNS Host Name [Type = UnicodeString]: name of computer account as registered in DNS. The value of dNSHostName attribute of new computer object. For manually created computer account objects this field has value -.

  • Service Principal Names [Type = UnicodeString]: The list of SPNs, registered for computer account. For new computer accounts it will typically contain HOST SPNs and RestrictedKrbHost SPNs. The value of servicePrincipalName attribute of new computer object. For manually created computer objects it is typically equals -. This is an example of Service Principal Names field for new domain joined workstation:

    HOST/Win81.contoso.local

    RestrictedKrbHost/Win81.contoso.local

    HOST/WIN81

    RestrictedKrbHost/WIN81

Additional Information:

  • Privileges [Type = UnicodeString]: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as -. See full list of user privileges in the table below:
Privilege Name User Right Group Policy Name Description
SeAssignPrimaryTokenPrivilege Replace a process-level token Required to assign the primary token of a process.
With this privilege, the user can initiate a process to replace the default token associated with a started subprocess.
SeAuditPrivilege Generate security audits With this privilege, the user can add entries to the security log.
SeBackupPrivilege Back up files and directories - Required to perform backup operations.
With this privilege, the user can bypass file and directory, registry, and other persistent object permissions for the purposes of backing up the system.
This privilege causes the system to grant all read access control to any file, regardless of the access control list (ACL) specified for the file. Any access request other than read is still evaluated with the ACL. The following access rights are granted if this privilege is held:
READ_CONTROL
ACCESS_SYSTEM_SECURITY
FILE_GENERIC_READ
FILE_TRAVERSE
SeChangeNotifyPrivilege Bypass traverse checking Required to receive notifications of changes to files or directories. This privilege also causes the system to skip all traversal access checks.
With this privilege, the user can traverse directory trees even though the user may not have permissions on the traversed directory. This privilege does not allow the user to list the contents of a directory, only to traverse directories.
SeCreateGlobalPrivilege Create global objects Required to create named file mapping objects in the global namespace during Terminal Services sessions.
SeCreatePagefilePrivilege Create a pagefile With this privilege, the user can create and change the size of a pagefile.
SeCreatePermanentPrivilege Create permanent shared objects Required to create a permanent object.
This privilege is useful to kernel-mode components that extend the object namespace. Components that are running in kernel mode already have this privilege inherently; it is not necessary to assign them the privilege.
SeCreateSymbolicLinkPrivilege Create symbolic links Required to create a symbolic link.
SeCreateTokenPrivilege Create a token object Allows a process to create a token which it can then use to get access to any local resources when the process uses NtCreateToken() or other token-creation APIs.
When a process requires this privilege, we recommend using the LocalSystem account (which already includes the privilege), rather than creating a separate user account and assigning this privilege to it.
SeDebugPrivilege Debug programs Required to debug and adjust the memory of a process owned by another account.
With this privilege, the user can attach a debugger to any process or to the kernel. Developers who are debugging their own applications do not need this user right. Developers who are debugging new system components need this user right. This user right provides complete access to sensitive and critical operating system components.
SeEnableDelegationPrivilege Enable computer and user accounts to be trusted for delegation Required to mark user and computer accounts as trusted for delegation.
With this privilege, the user can set the Trusted for Delegation setting on a user or computer object.
The user or object that is granted this privilege must have write access to the account control flags on the user or computer object. A server process running on a computer (or under a user context) that is trusted for delegation can access resources on another computer using the delegated credentials of a client, as long as the account of the client does not have the Account cannot be delegated account control flag set.
SeImpersonatePrivilege Impersonate a client after authentication With this privilege, the user can impersonate other accounts.
SeIncreaseBasePriorityPrivilege Increase scheduling priority Required to increase the base priority of a process.
With this privilege, the user can use a process with Write property access to another process to increase the execution priority assigned to the other process. A user with this privilege can change the scheduling priority of a process through the Task Manager user interface.
SeIncreaseQuotaPrivilege Adjust memory quotas for a process Required to increase the quota assigned to a process.
With this privilege, the user can change the maximum memory that can be consumed by a process.
SeIncreaseWorkingSetPrivilege Increase a process working set Required to allocate more memory for applications that run in the context of users.
SeLoadDriverPrivilege Load and unload device drivers Required to load or unload a device driver.
With this privilege, the user can dynamically load and unload device drivers or other code in to kernel mode. This user right does not apply to Plug and Play device drivers.
SeLockMemoryPrivilege Lock pages in memory Required to lock physical pages in memory.
With this privilege, the user can use a process to keep data in physical memory, which prevents the system from paging the data to virtual memory on disk. Exercising this privilege could significantly affect system performance by decreasing the amount of available random access memory (RAM).
SeMachineAccountPrivilege Add workstations to domain With this privilege, the user can create a computer account.
This privilege is valid only on domain controllers.
SeManageVolumePrivilege Perform volume maintenance tasks Required to run maintenance tasks on a volume, such as remote defragmentation.
SeProfileSingleProcessPrivilege Profile single process Required to gather profiling information for a single process.
With this privilege, the user can use performance monitoring tools to monitor the performance of non-system processes.
SeRelabelPrivilege Modify an object label Required to modify the mandatory integrity level of an object.
SeRemoteShutdownPrivilege Force shutdown from a remote system Required to shut down a system using a network request.
SeRestorePrivilege Restore files and directories Required to perform restore operations. This privilege causes the system to grant all write access control to any file, regardless of the ACL specified for the file. Any access request other than write is still evaluated with the ACL. Additionally, this privilege enables you to set any valid user or group SID as the owner of a file. The following access rights are granted if this privilege is held:
WRITE_DAC
WRITE_OWNER
ACCESS_SYSTEM_SECURITY
FILE_GENERIC_WRITE
FILE_ADD_FILE
FILE_ADD_SUBDIRECTORY
DELETE
With this privilege, the user can bypass file, directory, registry, and other persistent objects permissions when restoring backed up files and directories and determines which users can set any valid security principal as the owner of an object.
SeSecurityPrivilege Manage auditing and security log Required to perform a number of security-related functions, such as controlling and viewing audit events in security event log.
With this privilege, the user can specify object access auditing options for individual resources, such as files, Active Directory objects, and registry keys.
A user with this privilege can also view and clear the security log.
SeShutdownPrivilege Shut down the system Required to shut down a local system.
SeSyncAgentPrivilege Synchronize directory service data This privilege enables the holder to read all objects and properties in the directory, regardless of the protection on the objects and properties. By default, it is assigned to the Administrator and LocalSystem accounts on domain controllers.
With this privilege, the user can synchronize all directory service data. This is also known as Active Directory synchronization.
SeSystemEnvironmentPrivilege Modify firmware environment values Required to modify the nonvolatile RAM of systems that use this type of memory to store configuration information.
SeSystemProfilePrivilege Profile system performance Required to gather profiling information for the entire system.
With this privilege, the user can use performance monitoring tools to monitor the performance of system processes.
SeSystemtimePrivilege Change the system time Required to modify the system time.
With this privilege, the user can change the time and date on the internal clock of the computer. Users that are assigned this user right can affect the appearance of event logs. If the system time is changed, events that are logged will reflect this new time, not the actual time that the events occurred.
SeTakeOwnershipPrivilege Take ownership of files or other objects Required to take ownership of an object without being granted discretionary access. This privilege allows the owner value to be set only to those values that the holder may legitimately assign as the owner of an object.
With this privilege, the user can take ownership of any securable object in the system, including Active Directory objects, files and folders, printers, registry keys, processes, and threads.
SeTcbPrivilege Act as part of the operating system This privilege identifies its holder as part of the trusted computer base.
This user right allows a process to impersonate any user without authentication. The process can therefore gain access to the same local resources as that user.
SeTimeZonePrivilege Change the time zone Required to adjust the time zone associated with the computer's internal clock.
SeTrustedCredManAccessPrivilege Access Credential Manager as a trusted caller Required to access Credential Manager as a trusted caller.
SeUndockPrivilege Remove computer from docking station Required to undock a laptop.
With this privilege, the user can undock a portable computer from its docking station without logging on.
SeUnsolicitedInputPrivilege Not applicable Required to read unsolicited input from a terminal device.

Table 8. User Privileges.

Security Monitoring Recommendations

For 4741(S): A computer account was created.

Important

For this event, also see Appendix A: Security monitoring recommendations for many audit events.

  • If your information security monitoring policy requires you to monitor computer account creation, monitor this event.

  • Consider whether to track the following fields and values:

Field and value to track Reason to track
SAM Account Name: empty or - This field must contain the computer account name. If it is empty or -, it might indicate an anomaly.
Display Name is not -
User Principal Name is not -
Home Directory is not -
Home Drive is not -
Script Path is not -
Profile Path is not -
User Workstations is not -
AllowedToDelegateTo is not -		 Typically these fields are - for new computer accounts. Other values might indicate an anomaly and should be monitored.
Password Last Set is <never> This typically means this is a manually created computer account, which you might need to monitor.
Account Expires is not <never> Typically this field is <never> for new computer accounts. Other values might indicate an anomaly and should be monitored.
Primary Group ID is any value other than 515. Typically, the Primary Group ID value is one of the following:
516 for domain controllers
521 for read only domain controllers (RODCs)
515 for servers and workstations (domain computers)
If the Primary Group ID is 516 or 521, it is a new domain controller or RODC, and the event should be monitored.
If the value is not 516, 521, or 515, it is not a typical value and should be monitored.
Old UAC Value is not 0x0 Typically this field is 0x0 for new computer accounts. Other values might indicate an anomaly and should be monitored.
SID History is not - This field will always be set to - unless the account was migrated from another domain.
Logon Hours value other than <value not set> This should always be <value not set> for new computer accounts.
  • Consider whether to track the following account control flags:
User account control flag to track Information about the flag
'Encrypted Text Password Allowed' – Enabled Should not be set for computer accounts. By default, it will not be set, and it cannot be set in the account properties in Active Directory Users and Computers.
'Server Trust Account' – Enabled Should be enabled only for domain controllers.
'Don't Expire Password' – Enabled Should not be enabled for new computer accounts, because the password automatically changes every 30 days by default. For computer accounts, this flag cannot be set in the account properties in Active Directory Users and Computers.
'Smartcard Required' – Enabled Should not be enabled for new computer accounts.
'Trusted For Delegation' – Enabled Should not be enabled for new member servers and workstations. It is enabled by default for new domain controllers.
'Not Delegated' – Enabled Should not be enabled for new computer accounts.
'Use DES Key Only' – Enabled Should not be enabled for new computer accounts. For computer accounts, it cannot be set in the account properties in Active Directory Users and Computers.
'Don't Require Preauth' – Enabled Should not be enabled for new computer accounts. For computer accounts, it cannot be set in the account properties in Active Directory Users and Computers.
'Trusted To Authenticate For Delegation' – Enabled Should not be enabled for new computer accounts by default.