Extra Window Memory Injection

Created the Saturday 23 March 2019. Updated 5 months, 3 weeks ago.

Before creating a window, graphical Windows-based processes must prescribe to or register a windows class, which stipulate appearance and behavior (via windows procedures, which are functions that handle input/output of data).

Registration of new windows classes can include a request for up to 40 bytes of Extra Window Memory (EWM) to be appended to the allocated memory of each instance of that class. This EWM is intended to store data specific to that window and has specific application programming interface (API) functions to set and get its value.

Adversaries may inject malicious code into process via Extra Window Memory (EWM) in order to evade process-based defenses as well as possibly elevate privileges. EWM injection is a method of executing arbitrary code in the address space of a separate live process.


Technique Identifiers

U1219 E1055.011

Technique Tags

EWMI Code Injection


Featured Windows API's

Below, you will find a list of the most commonly used Windows API's that are currently utilized by malware authors for current evasion technique. This list is meant to provide an overview of the API's that are commonly used for this purpose. If there are any API's that you feel should be included on this list, please do not hesitate to contact us. We will be happy to update the list and provide any additional information or documentation that may be helpful.

Code Snippets

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.


Subscribe to our Newsletter

Don't miss out on the latest and greatest updates from us! Subscribe to our newsletter and be the first to know about exciting content and future updates.