Privilege Escalation: Scheduled Tasks & DLL Hijacking
In the pursuit of privilege escalation, understanding how attackers exploit system functionalities is crucial. This module delves into two common techniques: leveraging Scheduled Tasks and exploiting DLL Hijacking vulnerabilities.
Scheduled Tasks for Privilege Escalation
Scheduled Tasks are a powerful Windows feature that allows administrators to automate the execution of programs or scripts at specific times or in response to certain events. Attackers can exploit misconfigured scheduled tasks to gain higher privileges.
- Runs with high privileges (e.g., SYSTEM). 2. Executes a program/script in a location writable by a low-privileged user.
DLL Hijacking
DLL Hijacking is a vulnerability that occurs when an application loads a Dynamic Link Library (DLL) from an untrusted location before it searches in its legitimate, trusted location. This allows an attacker to place a malicious DLL with the same name in a location that the application will find first.
The DLL search order is a critical concept. Imagine an application needing a specific tool (DLL). It first checks its immediate workspace (current directory), then the general toolbox (System32), and finally the main storage (Windows directory). If the workspace is compromised, the wrong tool is picked up first. This visual represents the prioritized search path.
Text-based content
Library pages focus on text content
| Feature | Scheduled Tasks | DLL Hijacking |
|---|---|---|
| Primary Mechanism | Exploiting automated execution of programs. | Exploiting application's DLL loading order. |
| Target | System-level scheduled tasks. | Applications that load DLLs insecurely. |
| Privilege Gain | Elevated privileges of the scheduled task (e.g., SYSTEM). | Privileges of the compromised application. |
| Exploitation Vector | Modifying executables run by tasks in writable locations. | Placing malicious DLLs in early-searched directories. |
Practical Application and Tools
For OSCP preparation, understanding how to identify and exploit these vulnerabilities is key. This involves enumeration, analysis, and payload creation.
Loading diagram...
Similarly, for DLL hijacking, enumeration tools can help identify applications that load DLLs from potentially insecure locations. Crafting a malicious DLL and placing it correctly is the next step.
Remember, successful privilege escalation often relies on thorough enumeration and understanding the target system's configuration and behavior.
Learning Resources
Official Microsoft documentation explaining the Windows Task Scheduler, its components, and how it functions. Essential for understanding the target system.
An overview of DLL hijacking vulnerabilities from the Open Web Application Security Project, detailing the attack vector and its implications.
A comprehensive guide on exploiting scheduled tasks for privilege escalation on Windows systems, including practical examples and commands.
A white paper from SANS Institute detailing DLL hijacking, its causes, and methods for detection and prevention.
A foundational PDF from Offensive Security covering various Windows privilege escalation techniques, including scheduled tasks and DLLs.
A detailed blog post explaining the DLL search order and how to exploit it for privilege escalation on various Windows versions.
A video tutorial demonstrating how PowerShell can be used to identify and exploit privilege escalation vectors, including scheduled tasks.
The Sysinternals Suite contains powerful tools like Process Explorer and Autoruns, invaluable for enumerating processes, scheduled tasks, and loaded DLLs.
A practical demonstration of how to perform DLL hijacking attacks on Windows systems, showing the steps involved in exploitation.
While a study guide for Pentest+, this PDF often contains relevant sections on privilege escalation techniques like scheduled tasks, offering a structured learning approach.