The Red Team Vade Mecum
  • The Red Team Vade Mecum
  • Techniques
    • Defense Evasion
      • Binary Properties and Code Signing
      • ATA/ATP
        • Important Note
        • Intro
        • Lateral Movement
        • Domain Dominance
        • Identification
        • Recon
        • Blocking/Disabling Telemetry
          • Trusted Installer
      • Tips and Tricks
      • Basics
        • IOCs
          • High Level Overview of EDR technologies
        • Sandbox Evasion
        • Obfuscating Imports
          • Bootstrapping
        • Encrypting Strings
      • Disabling/Patching Telemetry
        • ETW Bypasses
        • AMSI Bypasses
      • Minimization
        • Commands to Avoid
        • Pivoting
        • Benefits of Using APIs
        • Thread-less Payload Execution
        • DLL Hollowing
      • Misdirection
        • Command Line Argument Spoofing
        • PPID Spoofing via CreateProcess
        • Switching Parents
          • Dechaining via WMI
      • Hiding our Payloads
        • Event Logs
        • File metadata
        • Registry Keys
        • ADS
      • IPC For Evasion and Control
    • Privilege Escalation
      • Hunting For Passwords
      • To System
        • New Service
        • Named Pipe Impersonation
        • Local Exploits
        • AlwaysInstallElevated
      • Hijacking Execution
        • Environment Variable interception
        • DLL Hijacking
      • Insecure Permissions
        • Missing Services and Tasks
        • Misconfigured Registry Hives
        • Insecure Binary Path
        • Unquoted Service Paths
    • Enumeration
      • Situational Awareness
      • Recon Commands
        • .NET AD Enum commands
        • WMIC commands
          • WMI queries from c++
    • Execution
      • Cool ways of Calling a Process
      • One Liners
    • Initial Access
      • Tips and Tricks
      • Tools
      • Staging/Stagers
      • MS Office
        • Macros
          • Evasion
            • VBA Stomping
            • Revert To Legacy Warning in Excel
            • Sandbox Evasion
          • Info Extraction
          • Inline Shapes
          • .MAM Files
          • PowerPoint
          • ACCDE
          • Shellcode Execution
          • Info Extraction
          • Dechaining Macros
        • Field Abuse
        • DDE
      • Payload Delivery
      • File Formats
        • MSG
        • RTF
        • REG
        • BAT
        • MSI Files
        • IQY
        • CHM
        • LNK
          • Using LNK to Automatically Download Payloads
        • HTA
    • Lateral Movement
      • Linux
        • SSH Hijacking
        • RDP
        • Impacket
      • No Admin?
      • Checking for access
      • Poison Handler
      • WinRM
      • AT
      • PsExec
      • WMI
      • Service Control
      • DCOM
      • RDP
      • SCShell
    • Code Injection
      • Hooking
        • Detours
      • CreateRemoteThread
      • DLL Injection
      • APC Queue Code Injection
      • Early Bird Injection
    • Persistence
      • Scheduled Tasks
        • AT
      • MS Office
      • SQL
      • Admin Level
        • SSP
        • Services
        • Default File Extension
        • AppCert DLLs
        • Time Provider
        • Waitfor
        • WinLogon
        • Netsh Dlls
        • RDP Backdoors
        • AppInit Dlls
        • Port Monitor
        • WMI Event Subscriptions
      • User Level
        • LNK
        • Startup Folder
        • Junction folders
        • Registry Keys
        • Logon Scripts
        • Powershell Profiles
        • Screen Savers
  • Infrastructure
    • SQL
      • MS SQL
        • Basics
        • Finding Sql Servers
        • Privilege Escalation
        • Post Exploitation
  • Other
    • Vulnerability Discovery
      • Web Vulnerabilities
        • Code Grepping
          • PHP Cheatsheet
    • Windows Internals
      • Unorganized Notes
Powered by GitBook
On this page

Was this helpful?

  1. Techniques
  2. Privilege Escalation
  3. Hijacking Execution

Environment Variable interception

PreviousHijacking ExecutionNextDLL Hijacking

Last updated 3 years ago

Was this helpful?

The PATH environment variable contains a list of directories which programs rely on to determine the locations of a certain program if the full path to the program is not given.

If any directory is listed before the Windows Directory %SystemRoot%\System32, a program may be placed in the directory to hijack execution flow as that folder will be checked first before System32.

For example, if c:\path precedes %SystemRoot%\System32, the c:\path folder will be checked for the certain program before it checks system32. If we placed a program in c:\path called powershell.exe, the "powershell.exe" in the c:\path folder will be called instead of the powershell.exe in system32.

We need 2 requirements to exploit this:

  1. PATH contains a writable folder to the attacker

  2. The writable folder is before the folder that contains the legit binary

Let's first look at the system wide variables with reg:

reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment"

As we can see in the above, the document folder precedes the system32 folder.

Let's try copying calc renamed to notepad to our documents folder copy c:\windows\system32\calc.exe c:\Users\front\Documents\notepad.exe

now lets open up cmd and try to open notepad.

As you can see, calc will popup instead.

We can modify this to run our malware which will run our shellcode and start notepad.exe at the same time

Because this is a system wide variable, any admin user who tries to run notepad will run calc.exe with elevated privileges which can lead to privilege escalation if we the admin user to run our malware.