[REQ-DC-110] Configure User Rights: Back up files and directories on Domain Controllers

Target Scope

  • Applicable Systems: Domain Controllers (Tier 0 Active Directory infrastructure). (For Tier 0 Privileged Access Workstations, refer to tightened baseline REQ-PAW-096). (For Tier 2 Client Workstations and Member Servers, refer to standard baseline REQ-END-100).
  • Operating Systems: Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.

Implementation Details

  • Priority: High
  • GPO Path / Registry Location:
    • Policy Display Name: Back up files and directories
    • Privilege Constant: SeBackupPrivilege
    • GPO Path: Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment\Back up files and directories
    • Registry Location: Stored inside local security database under privilege SeBackupPrivilege set to *S-1-5-32-544 (Administrators).

Rationale

The SeBackupPrivilege grants the caller the capability to bypass all read-access security controls (Discretionary Access Control Lists - DACLs) across the entire NTFS filesystem and Windows Registry. When an application opens a file handle specifying the FILE_FLAG_BACKUP_SEMANTICS flag in Win32 CreateFile calls, the Windows kernel I/O manager and Object Manager explicitly bypass standard security descriptor evaluation. This design allows legitimate backup utilities to archive files without requiring explicit read permissions on every individual object.

1. Technical Threat Vector & Abuse Mechanics

Adversaries routinely target accounts holding SeBackupPrivilege for rapid credential harvesting and full domain escalation. Possession of this privilege allows an attacker to directly copy protected credential stores that are otherwise locked and ACL-protected by the operating system, including: (1) The Active Directory database file ntds.dit on Domain Controllers; (2) The local Security Account Manager (SAM) and SYSTEM registry hives on workstations and servers; (3) Sensitive configuration files, BitLocker recovery keys, and private certificates. Using standard tools such as reg.exe save, wbadmin.exe, Volume Shadow Copy Service (vssadmin), or PowerShell robocopy with /b, an attacker with SeBackupPrivilege can dump all password hashes and Kerberos keys across the entire domain.

2. Architectural Defense & Least Privilege Enforcement

Domain Controllers are the root of trust for the entire Active Directory forest, storing the directory database (ntds.dit), Kerberos master keys (krbtgt), and password hashes for all enterprise identities. Unrestricted allocation of user rights on Domain Controllers introduces devastating forest-compromise risks. Enforcing strict assignment of this privilege ensures that directory synchronization, authentication packages, and system execution remain strictly bounded to authorized directory components and Domain Administrators.

Restricting SeBackupPrivilege strictly to Administrators (S-1-5-32-544) prevents non-administrative users and compromised service accounts from abusing backup semantics to exfiltrate critical operating system secrets. On Tier 0 systems (Domain Controllers and PAWs), broad groups such as Backup Operators should be stripped of this right, and dedicated Group Managed Service Accounts (gMSAs) with tightly scoped time-limited access should be utilized for automated backup routines.

3. MITRE ATT&CK Mapping

  • T1003.002 - OS Credential Dumping: Security Account Manager
  • T1003.003 - OS Credential Dumping: NTDS
  • T1005 - Data from Local System
  • T1083 - File and Directory Discovery

Legacy Impact & Compatibility

  • Operational Impact: Restricting SeBackupPrivilege prevents unauthorized read-bypass across system drives. Enterprise backup agents (e.g., Commvault, Veeam, NetBackup) that run under non-administrative service accounts may fail if they rely on SeBackupPrivilege; organizations must configure dedicated service identities or run backup software under managed accounts with explicit backup rights. Monitor Security Event ID 4672 and Event ID 4673 for invocations of SeBackupPrivilege outside of scheduled backup maintenance windows.

Implementation Steps

Option A: Group Policy Object (GPO) Configuration (Preferred)

  1. Open the Group Policy Management Console (gpmc.msc).
  2. Navigate to the targeted GPO linked to Tier 0 Domain Controller systems (e.g., Default Domain Controllers Policy).
  3. In the console tree, browse to: Computer Configuration\Policies\Windows Settings\Security Settings\Local Policies\User Rights Assignment
  4. Open the policy Back up files and directories.
  5. Select the Define these policy settings check box.
  6. Configure the security principal allocation to: *S-1-5-32-544 (Administrators).
  7. Click Apply and OK.
  8. Apply and verify policy enforcement across target hosts using gpupdate /force and inspect with secedit /export /cfg C:\Windows\Temp\sec_audit.cfg.

Option B: PowerShell & Registry Configuration (Remediation / Non-GPO)

Download Script: Configure-DcUraSeBackupPrivilege.ps1

# Configure-DcUraSeBackupPrivilege.ps1
# Configure-DcUraSeBackupPrivilege.ps1
$SecTempDir = Join-Path $env:TEMP "SecurityTemplates"
if (-not (Test-Path $SecTempDir)) { New-Item -Path $SecTempDir -ItemType Directory -Force | Out-Null }
$CfgFile = Join-Path $SecTempDir "ura_sebackupprivilege.cfg"
$DbFile = Join-Path $SecTempDir "secedit_sebackupprivilege.sdb"
$LogFile = Join-Path $SecTempDir "secedit.log"

$Process = Start-Process secedit -ArgumentList "/export /cfg `"$CfgFile`"" -Wait -NoNewWindow -PassThru
if ($Process.ExitCode -ne 0) { Throw "Failed to export security template" }

$ConfigText = Get-Content -Path $CfgFile -Raw
if ($ConfigText -notmatch "\[Privilege Rights\]") {
    $ConfigText += "`r`n[Privilege Rights]`r`n"
}

$Lines = $ConfigText -split "`r?`n"
$NewLines = @()
$InPriv = $false
$KeyAdded = $false

foreach ($Line in $Lines) {
    if ($Line -match "^\[(.*)\]$") {
        if ($Matches[1] -eq "Privilege Rights") {
            $InPriv = $true
        } else {
            $InPriv = $false
        }
    }
    if ($InPriv -and $Line -match "^\s*SeBackupPrivilege\s*=") {
        $NewLines += "SeBackupPrivilege = *S-1-5-32-544"
        $KeyAdded = $true
    } else {
        $NewLines += $Line
    }
}

if (-not $KeyAdded) {
    # Find Privilege Rights section index and insert it right after
    $Idx = $NewLines.IndexOf("[Privilege Rights]")
    if ($Idx -ge 0) {
        $NewLines.Insert($Idx + 1, "SeBackupPrivilege = *S-1-5-32-544")
    } else {
        $NewLines += "SeBackupPrivilege = *S-1-5-32-544"
    }
}

$NewLines | Set-Content -Path $CfgFile -Force
$Proc = Start-Process secedit -ArgumentList "/configure /db `"$DbFile`" /cfg `"$CfgFile`" /areas USER_RIGHTS /log `"$LogFile`"" -Wait -NoNewWindow -PassThru
if ($Proc.ExitCode -ne 0) { Throw "Failed to configure secedit user rights" }
Remove-Item -Path $CfgFile, $DbFile -ErrorAction SilentlyContinue

To audit the hardening status: Download Script: Get-DcUraSeBackupPrivilegeStatus.ps1

# Get-DcUraSeBackupPrivilegeStatus.ps1
# Get-DcUraSeBackupPrivilegeStatus.ps1
$SecTempDir = Join-Path $env:TEMP "SecurityTemplates"
if (-not (Test-Path $SecTempDir)) { New-Item -Path $SecTempDir -ItemType Directory -Force | Out-Null }
$CfgFile = Join-Path $SecTempDir "ura_audit_sebackupprivilege.cfg"

$Process = Start-Process secedit -ArgumentList "/export /cfg `"$CfgFile`"" -Wait -NoNewWindow -PassThru
if ($Process.ExitCode -ne 0) {
    Write-Output "Non-Compliant"
    exit 1
}

$ConfigText = Get-Content -Path $CfgFile -Raw
Remove-Item -Path $CfgFile -ErrorAction SilentlyContinue

$Match = $ConfigText -match "(?mi)^\s*SeBackupPrivilege\s*=\s*(.*)$"
$CurrentValue = ""
if ($Match) {
    $CurrentValue = $Matches[1].Trim()
}

$Expected = "*S-1-5-32-544"
if ($CurrentValue -eq $Expected) {
    Write-Output "Compliant"
    exit 0
} else {
    Write-Output "Non-Compliant"
    exit 1
}

Sources & Compliance References

  • ANSSI Active Directory Hardening Guide: ANSSI Active Directory Hardening Guide: R28 (User Rights Assignment)
  • CIS Benchmark: 2.2.4 (L1) Ensure 'Back up files and directories' is set to 'Administrators'
  • Microsoft Security Baseline: User Rights Configuration specifications
  • Microsoft Learn: User Rights Assignment Reference

results matching ""

    No results matching ""