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Technical

Well-known security identifiers in Windows operating systems

This article was previously published under Microsoft’s Q243330

Summary

A security identifier (SID) is a unique value of variable length that is used to identify a security principal or security group in Windows operating systems. Well-known SIDs are a group of SIDs that identify generic users or generic groups. Their values remain constant across all operating systems.

This information is useful for troubleshooting issues involving security. It is also useful for potential display problems that may be seen in the ACL editor. A SID may be displayed in the ACL editor instead of the user or group name.

Well-known SIDs:

  • SID: S-1-0
    Name: Null Authority
    Description: An identifier authority.
  • SID: S-1-0-0
    Name: Nobody
    Description: No security principal.
  • SID: S-1-1
    Name: World Authority
    Description: An identifier authority.
  • SID: S-1-1-0
    Name: Everyone
    Description: A group that includes all users, even anonymous users and guests. Membership is controlled by the operating system.

    Note By default, the Everyone group no longer includes anonymous users on a computer that is running Windows XP Service Pack 2 (SP2).

  • SID: S-1-2
    Name: Local Authority
    Description: An identifier authority.
  • SID: S-1-2-0
    Name: Local
    Description: A group that includes all users who have logged on locally.
  • SID: S-1-2-1
    Name: Console Logon
    Description: A group that includes users who are logged on to the physical console.

    Note Added in Windows 7 and Windows Server 2008 R2

  • SID: S-1-3
    Name: Creator Authority
    Description: An identifier authority.
  • SID: S-1-3-0
    Name: Creator Owner
    Description: A placeholder in an inheritable access control entry (ACE). When the ACE is inherited, the system replaces this SID with the SID for the object’s creator.
  • SID: S-1-3-1
    Name: Creator Group
    Description: A placeholder in an inheritable ACE. When the ACE is inherited, the system replaces this SID with the SID for the primary group of the object’s creator. The primary group is used only by the POSIX subsystem.
  • SID: S-1-3-2
    Name: Creator Owner Server
    Description: This SID is not used in Windows 2000.
  • SID: S-1-3-3
    Name: Creator Group Server
    Description: This SID is not used in Windows 2000.
  • SID: S-1-3-4 Name: Owner Rights
    Description: A group that represents the current owner of the object. When an ACE that carries this SID is applied to an object, the system ignores the implicit READ_CONTROL and WRITE_DAC permissions for the object owner.

    Note: Added in Windows Vista and Windows Server 2008

  • SID: S-1-4
    Name: Non-unique Authority
    Description: An identifier authority.
  • SID: S-1-5
    Name: NT Authority
    Description: An identifier authority.
  • SID: S-1-5-1
    Name: Dialup
    Description: A group that includes all users who have logged on through a dial-up connection. Membership is controlled by the operating system.
  • SID: S-1-5-2
    Name: Network
    Description: A group that includes all users that have logged on through a network connection. Membership is controlled by the operating system.
  • SID: S-1-5-3
    Name: Batch
    Description: A group that includes all users that have logged on through a batch queue facility. Membership is controlled by the operating system.
  • SID: S-1-5-4
    Name: Interactive
    Description: A group that includes all users that have logged on interactively. Membership is controlled by the operating system.
  • SID: S-1-5-5-X-Y
    Name: Logon Session
    Description: A logon session. The X and Y values for these SIDs are different for each session.
  • SID: S-1-5-6
    Name: Service
    Description: A group that includes all security principals that have logged on as a service. Membership is controlled by the operating system.
  • SID: S-1-5-7
    Name: Anonymous
    Description: A group that includes all users that have logged on anonymously. Membership is controlled by the operating system.
  • SID: S-1-5-8
    Name: Proxy
    Description: This SID is not used in Windows 2000.
  • SID: S-1-5-9
    Name: Enterprise Domain Controllers
    Description: A group that includes all domain controllers in a forest that uses an Active Directory directory service. Membership is controlled by the operating system.
  • SID: S-1-5-10
    Name: Principal Self
    Description: A placeholder in an inheritable ACE on an account object or group object in Active Directory. When the ACE is inherited, the system replaces this SID with the SID for the security principal who holds the account.
  • SID: S-1-5-11
    Name: Authenticated Users
    Description: A group that includes all users whose identities were authenticated when they logged on. Membership is controlled by the operating system.
  • SID: S-1-5-12
    Name: Restricted Code
    Description: This SID is reserved for future use.
  • SID: S-1-5-13
    Name: Terminal Server Users
    Description: A group that includes all users that have logged on to a Terminal Services server. Membership is controlled by the operating system.
  • SID: S-1-5-14
    Name: Remote Interactive Logon
    Description: A group that includes all users who have logged on through a terminal services logon.
  • SID: S-1-5-15
    Name: This Organization
    Description: A group that includes all users from the same organization. Only included with AD accounts and only added by a Windows Server 2003 or later domain controller.
  • SID: S-1-5-17
    Name: This Organization
    Description: An account that is used by the default Internet Information Services (IIS) user.
  • SID: S-1-5-18
    Name: Local System
    Description: A service account that is used by the operating system.
  • SID: S-1-5-19
    Name: NT Authority
    Description: Local Service
  • SID: S-1-5-20
    Name: NT Authority
    Description: Network Service
  • SID: S-1-5-21domain-500
    Name: Administrator
    Description: A user account for the system administrator. By default, it is the only user account that is given full control over the system.
  • SID: S-1-5-21domain-501
    Name: Guest
    Description: A user account for people who do not have individual accounts. This user account does not require a password. By default, the Guest account is disabled.
  • SID: S-1-5-21domain-502
    Name: KRBTGT
    Description: A service account that is used by the Key Distribution Center (KDC) service.
  • SID: S-1-5-21domain-512
    Name: Domain Admins
    Description: A global group whose members are authorized to administer the domain. By default, the Domain Admins group is a member of the Administrators group on all computers that have joined a domain, including the domain controllers. Domain Admins is the default owner of any object that is created by any member of the group.
  • SID: S-1-5-21domain-513
    Name: Domain Users
    Description: A global group that, by default, includes all user accounts in a domain. When you create a user account in a domain, it is added to this group by default.
  • SID: S-1-5-21domain-514
    Name: Domain Guests
    Description: A global group that, by default, has only one member, the domain’s built-in Guest account.
  • SID: S-1-5-21domain-515
    Name: Domain Computers
    Description: A global group that includes all clients and servers that have joined the domain.
  • SID: S-1-5-21domain-516
    Name: Domain Controllers
    Description: A global group that includes all domain controllers in the domain. New domain controllers are added to this group by default.
  • SID: S-1-5-21domain-517
    Name: Cert Publishers
    Description: A global group that includes all computers that are running an enterprise certification authority. Cert Publishers are authorized to publish certificates for User objects in Active Directory.
  • SID: S-1-5-21root domain-518
    Name: Schema Admins
    Description: A universal group in a native-mode domain; a global group in a mixed-mode domain. The group is authorized to make schema changes in Active Directory. By default, the only member of the group is the Administrator account for the forest root domain.
  • SID: S-1-5-21root domain-519
    Name: Enterprise Admins
    Description: A universal group in a native-mode domain; a global group in a mixed-mode domain. The group is authorized to make forest-wide changes in Active Directory, such as adding child domains. By default, the only member of the group is the Administrator account for the forest root domain.
  • SID: S-1-5-21domain-520
    Name: Group Policy Creator Owners
    Description: A global group that is authorized to create new Group Policy objects in Active Directory. By default, the only member of the group is Administrator.
  • SID: S-1-5-21domain-553
    Name: RAS and IAS Servers
    Description: A domain local group. By default, this group has no members. Servers in this group have Read Account Restrictions and Read Logon Information access to User objects in the Active Directory domain local group.
  • SID: S-1-5-32-544
    Name: Administrators
    Description: A built-in group. After the initial installation of the operating system, the only member of the group is the Administrator account. When a computer joins a domain, the Domain Admins group is added to the Administrators group. When a server becomes a domain controller, the Enterprise Admins group also is added to the Administrators group.
  • SID: S-1-5-32-545
    Name: Users
    Description: A built-in group. After the initial installation of the operating system, the only member is the Authenticated Users group. When a computer joins a domain, the Domain Users group is added to the Users group on the computer.
  • SID: S-1-5-32-546
    Name: Guests
    Description: A built-in group. By default, the only member is the Guest account. The Guests group allows occasional or one-time users to log on with limited privileges to a computer’s built-in Guest account.
  • SID: S-1-5-32-547
    Name: Power Users
    Description: A built-in group. By default, the group has no members. Power users can create local users and groups; modify and delete accounts that they have created; and remove users from the Power Users, Users, and Guests groups. Power users also can install programs; create, manage, and delete local printers; and create and delete file shares.
  • SID: S-1-5-32-548
    Name: Account Operators
    Description: A built-in group that exists only on domain controllers. By default, the group has no members. By default, Account Operators have permission to create, modify, and delete accounts for users, groups, and computers in all containers and organizational units of Active Directory except the Builtin container and the Domain Controllers OU. Account Operators do not have permission to modify the Administrators and Domain Admins groups, nor do they have permission to modify the accounts for members of those groups.
  • SID: S-1-5-32-549
    Name: Server Operators
    Description: A built-in group that exists only on domain controllers. By default, the group has no members. Server Operators can log on to a server interactively; create and delete network shares; start and stop services; back up and restore files; format the hard disk of the computer; and shut down the computer.
  • SID: S-1-5-32-550
    Name: Print Operators
    Description: A built-in group that exists only on domain controllers. By default, the only member is the Domain Users group. Print Operators can manage printers and document queues.
  • SID: S-1-5-32-551
    Name: Backup Operators
    Description: A built-in group. By default, the group has no members. Backup Operators can back up and restore all files on a computer, regardless of the permissions that protect those files. Backup Operators also can log on to the computer and shut it down.
  • SID: S-1-5-32-552
    Name: Replicators
    Description: A built-in group that is used by the File Replication service on domain controllers. By default, the group has no members. Do not add users to this group.
  • SID: S-1-5-64-10
    Name: NTLM Authentication
    Description: A SID that is used when the NTLM authentication package authenticated the client
  • SID: S-1-5-64-14
    Name: SChannel Authentication
    Description: A SID that is used when the SChannel authentication package authenticated the client.
  • SID: S-1-5-64-21
    Name: Digest Authentication
    Description: A SID that is used when the Digest authentication package authenticated the client.
  • SID: S-1-5-80
    Name: NT Service
    Description: An NT Service account prefix
  • SID: S-1-16-0
    Name: Untrusted Mandatory Level
    Description: An untrusted integrity level. Note Added in Windows Vista and Windows Server 2008

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-4096
    Name: Low Mandatory Level
    Description: A low integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-8192
    Name: Medium Mandatory Level
    Description: A medium integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-8448
    Name: Medium Plus Mandatory Level
    Description: A medium plus integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-12288
    Name: High Mandatory Level
    Description: A high integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-16384
    Name: System Mandatory Level
    Description: A system integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-20480
    Name: Protected Process Mandatory Level
    Description: A protected-process integrity level.

    Note Added in Windows Vista and Windows Server 2008

  • SID: S-1-16-28672
    Name: Secure Process Mandatory Level
    Description: A secure process integrity level.

    Note Added in Windows Vista and Windows Server 2008

The following groups will show as SIDs until a Windows Server 2003 domain controller is made the primary domain controller (PDC) operations master role holder. (The “operations master” is also known as flexible single master operations or FSMO.) Additional new built-in groups that are created when a Windows Server 2003 domain controller is added to the domain are:

  • SID: S-1-5-32-554
    Name: BUILTINPre-Windows 2000 Compatible Access
    Description: An alias added by Windows 2000. A backward compatibility group which allows read access on all users and groups in the domain.
  • SID: S-1-5-32-555
    Name: BUILTINRemote Desktop Users
    Description: An alias. Members in this group are granted the right to logon remotely.
  • SID: S-1-5-32-556
    Name: BUILTINNetwork Configuration Operators
    Description: An alias. Members in this group can have some administrative privileges to manage configuration of networking features.
  • SID: S-1-5-32-557
    Name: BUILTINIncoming Forest Trust Builders
    Description: An alias. Members of this group can create incoming, one-way trusts to this forest.
  • SID: S-1-5-32-558
    Name: BUILTINPerformance Monitor Users
    Description: An alias. Members of this group have remote access to monitor this computer.
  • SID: S-1-5-32-559
    Name: BUILTINPerformance Log Users
    Description: An alias. Members of this group have remote access to schedule logging of performance counters on this computer.
  • SID: S-1-5-32-560
    Name: BUILTINWindows Authorization Access Group
    Description: An alias. Members of this group have access to the computed tokenGroupsGlobalAndUniversal attribute on User objects.
  • SID: S-1-5-32-561
    Name: BUILTINTerminal Server License Servers
    Description: An alias. A group for Terminal Server License Servers. When Windows Server 2003 Service Pack 1 is installed, a new local group is created.
  • SID: S-1-5-32-562
    Name: BUILTINDistributed COM Users
    Description: An alias. A group for COM to provide computerwide access controls that govern access to all call, activation, or launch requests on the computer.

The following groups will show as SIDs until a Windows Server 2008 or Windows Server 2008 R2 domain controller is made the primary domain controller (PDC) operations master role holder. (The “operations master” is also known as flexible single master operations or FSMO.) Additional new built-in groups that are created when a Windows Server 2008 or Windows Server 2008 R2 domain controller is added to the domain are:

  • SID: S-1-5- 21domain -498
    Name: Enterprise Read-only Domain Controllers
    Description: A Universal group. Members of this group are Read-Only Domain Controllers in the enterprise
  • SID: S-1-5- 21domain -521
    Name: Read-only Domain Controllers
    Description: A Global group. Members of this group are Read-Only Domain Controllers in the domain
  • SID: S-1-5-32-569
    Name: BUILTINCryptographic Operators
    Description: A Builtin Local group. Members are authorized to perform cryptographic operations.
  • SID: S-1-5-21 domain -571
    Name: Allowed RODC Password Replication Group
    Description: A Domain Local group. Members in this group can have their passwords replicated to all read-only domain controllers in the domain.
  • SID: S-1-5- 21 domain -572
    Name: Denied RODC Password Replication Group
    Description: A Domain Local group. Members in this group cannot have their passwords replicated to any read-only domain controllers in the domain
  • SID: S-1-5-32-573
    Name: BUILTINEvent Log Readers
    Description: A Builtin Local group. Members of this group can read event logs from local machine.
  • SID: S-1-5-32-574
    Name: BUILTINCertificate Service DCOM Access
    Description: A Builtin Local group. Members of this group are allowed to connect to Certification Authorities in the enterprise.