Active Directory SID Quick Reference

• SID format: S-1-5-21-<domainID>-<RID>
• Domain ID: The long middle section (e.g. 3450839898-1007371689-2406560646) is constant for all accounts in the domain.
• RID: The last number (e.g. 7147) uniquely identifies the user or group.
• Identity resolution:

Get-ADUser -Identity <SID>
  

→ Returns the user object (SamAccountName, DistinguishedName, etc.).

Useful PowerShell Commands

Full details of user

Get-ADUser -Identity <SID> -Properties *
  

Group memberships

Get-ADUser -Identity <SID> | Get-ADPrincipalGroupMembership
  

Username → SID lookup

Get-ADUser -Identity <username> | Select SID
  

Ritual View 🌱

• Domain ID → temple walls (shared by all accounts).
• RID → unique scroll inside the shrine.
• SID → the true identity key, unchanged even if names are altered.