Created the Saturday 23 March 2019. Updated 2 months, 1 week ago.
Instead of passing the address of the LoadLibrary, malware can copy its malicious code into an existing open process and force it to execute (either via a small shellcode, or by calling
One advantage of PE injection over the
LoadLibrary technique is that the malware does not have to drop a malicious DLL on the disk. The malware allocates memory in a host process (e.g.
VirtualAllocEx), and instead of writing a “DLL path” it writes its malicious code by calling
WriteProcessMemory. However, the obstacle with this approach is the change of the base address of the copied image.
When a malware injects its PE into another process it will have a new base address which is unpredictable, requiring it to dynamically recompute the fixed addresses of its PE. To overcome this, the malware needs to find its relocation table address in the host process and resolve the absolute addresses of the copied image by looping through its relocation descriptors.
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.
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.