Now Reading: How to Leverage PowerShell for Penetration Testing on Windows Environments

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How to Leverage PowerShell for Penetration Testing on Windows Environments

November 28, 20234 min read

PowerShell is a versatile tool that can be used in the penetration testing of Windows environments to carry out a wide range of tasks, from information gathering to exploitation and post-exploitation activities. Below are detailed steps on how to leverage PowerShell for penetration testing:


Setting Up the Environment

  • Enable PowerShell Script Execution:
    • By default, Windows may not allow the execution of PowerShell scripts (as they might be set to Restricted). Use Set-ExecutionPolicy Unrestricted or Set-ExecutionPolicy Bypass to change the policy.
    • Ensure that you do this in an administrative context to apply the changes.
  • Remote Execution:
    • For remote exploitation, ensure that PowerShell Remoting is enabled on the target machine (Enable-PSRemoting command).
    • Use Enter-PSSession -ComputerName target to initiate a remote session.
  • Logging and Anti-Virus Considerations:
    • Be aware of potential logging on the target system. Examine and evade security systems such as antivirus software and Windows Defender that may block or log scripted activities.

Information Gathering and Reconnaissance

  • System Reconnaissance:
    • Use Get-ComputerInfo to gather system information like OS version, languages, and hardware details.
  • Network Reconnaissance:
    • Use Test-NetConnection for simple port scanning and network testing.
    • Leverage the Get-NetAdapter and Get-NetIPAddress cmdlets for detailed network interface and IP configuration.
  • User and Group Enumeration:
    • Employ Get-LocalUser and Get-LocalGroup to enumerate local users and groups.
    • For Active Directory environments, use Get-ADUser and Get-ADGroup along with the Active Directory PowerShell module.

Vulnerability Identification

  • Checking for Known Vulnerabilities:
    • Use PowerShell to cross-reference installed software (Get-WmiObject -Class Win32_Product) with online vulnerability databases.
  • Misconfigurations:
    • Search for misconfigurations in security settings, such as overly permissive file permissions (Get-Acl) or service configurations (Get-Service).
  • PowerShell Script-Based Scanners:
    • Utilize community scripts like PowerSploit or Nishang that contain modules specifically designed to discover vulnerabilities.

Exploitation

  • Script Execution for Exploitation:
    • Execute custom or pre-built PowerShell scripts to exploit known vulnerabilities.
    • PowerShell can be used to invoke reflective PE injection or to run shellcode directly in memory.
  • Pass-the-Hash and Credential Theft:
    • Leverage Invoke-Mimikatz from PowerSploit or similar functions to perform pass-the-hash attacks or dump credentials.
  • Privilege Escalation:
    • Use scripts to exploit service or application misconfigurations and gain higher privileges (Invoke-PrivEsc).

Post-Exploitation

  • Persistence:
    • Establish backdoors using PowerShell profiles ($profile) or by setting registry keys to autorun scripts.
    • Generate and deploy advanced payloads with tools like Empire or Cobalt Strike that have PowerShell integration.
  • Data Exfiltration:
    • Use PowerShell to compress data (Compress-Archive) and exfiltrate it from the network using various techniques (over HTTP, DNS, etc.).
  • Lateral Movement:
    • Utilize Invoke-Command to execute scripts on remote systems within the compromised network.
    • Move laterally using stolen credentials and PowerShell remoting.

Cleanup and Cover Tracks

  • Removing Footprints:
    • Use Remove-Item to delete files and clear event logs (Clear-EventLog) to cover activities.
    • Unset added registry keys and undo changes made for persistence.
  • Restore Execution Policy:
    • Reset the execution policy using Set-ExecutionPolicy to its original state to avoid detection.

Additional Tips

  • Always prefer stealthy methods for script execution; for instance, utilize Invoke-Expression (iex) cmdlet to execute encoded commands that are less likely to be caught by antivirus systems.
  • Regularly update your PowerShell toolkit with the latest versions of offensive PowerShell frameworks and modules.
  • Document every step and change to ensure that all modifications can be reversed during the cleanup phase.
  • Test the scripts and tools in a controlled environment before executing them in a live penetration test to avoid unexpected behavior.

By following these steps and considerations, you can effectively leverage the power of PowerShell for penetration testing in Windows environments. Always ensure that you’re authorized to perform penetration tests and that your actions comply with legal and ethical standards.

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