[REQ-PAW-096] Configure User Rights: Back up files and directories for PAWs

Target Scope

  • Applicable Systems: Privileged Access Workstations (PAWs) dedicated to Tier 0 and critical administrative functions. (For Tier 2 Client Workstations and Member Servers, refer to standard baseline REQ-END-100). (For Domain Controllers, refer to REQ-DC-110).
  • Operating Systems: Windows 10 Enterprise (1809 and above) and Windows 11 Enterprise.

Implementation Details

  • Priority: Medium
  • 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

Privileged Access Workstations (PAWs) serve as the clean-source platform for managing Tier 0 Active Directory and cloud infrastructure. Because administrative credentials exist in memory on these devices, strict isolation must be maintained at the operating system level. Restricting this user right strictly prevents lower-tier sessions, third-party software, or interactive users from interfering with administrative operations, upholding the Clean Source Principle and preventing token kidnapping or session hijacking.

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 PAW systems (e.g., GPO_Hardening_PAW).
  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-PawUraSeBackupPrivilege.ps1

# Configure-PawUraSeBackupPrivilege.ps1
# Configure-PawUraSeBackupPrivilege.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-PawUraSeBackupPrivilegeStatus.ps1

# Get-PawUraSeBackupPrivilegeStatus.ps1
# Get-PawUraSeBackupPrivilegeStatus.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

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