DLL injection definition

DLL injection

(also process injection)

DLL injection is a method, frequently referred to as process injection, where developers and cyberattackers alter a program’s functionality by executing extraneous code within another process’s realm. This approach hinges on the capabilities of Windows’ Dynamic Link Library (DLL), a type of file that can be loaded and executed dynamically by programs.

See also: code injection, PHP injection

DLL injection examples

Debugging and testing: Developers often use DLL injection to detect and fix bugs, or for stress testing under certain conditions.
Malware: Hackers use DLL injection to insert malicious code into running processes to avoid detection by security software.

Comparison to other techniques

DLL injection can be compared to techniques such as code injection or process hollowing. While code injection involves inserting code into a running process, DLL injection specifically inserts a DLL. Process hollowing, on the other hand, replaces the content of a running process with a malicious executable.

Advantages and disadvantages of DLL injection

Pros:

Testing and debugging: DLL injection allows developers to alter the behavior of a program without changing its source code.

Cons:

Malware: DLL injection can be used maliciously to run code that compromises system security.

Using DLL injection

While DLL injection can be used for legitimate purposes, it’s important to be aware of its potential for misuse. Ensuring security software is up-to-date is vital to protect against malicious DLL injections.