Process Injection: Asynchronous Procedure Call Defense Evasion [Mitre]

Adversaries may inject malicious code into processes via the asynchronous procedure call (APC) queue in order to evade process-based defenses as well as possibly elevate privileges. APC injection is a method of executing arbitrary code in the address space of a separate live process.

APC injection is commonly performed by attaching malicious code to the APC Queue of a process's …

Process Injection: Thread Execution Hijacking Defense Evasion [Mitre]

Adversaries may inject malicious code into hijacked processes in order to evade process-based defenses as well as possibly elevate privileges. Thread Execution Hijacking is a method of executing arbitrary code in the address space of a separate live process.

Thread Execution Hijacking is commonly performed by suspending an existing process then unmapping/hollowing its memory, which can then be replaced with …

APC injection Process Manipulating

Malware can take advantage of Asynchronous Procedure Calls (APC) to force another thread to execute their custom code by attaching it to the APC Queue of the target thread.

Each thread has a queue of APCs which are waiting for execution upon the target thread entering alterable state.

A thread enters an alert table state if it calls SleepEx, …

Thread Execution Hijacking Process Manipulating

Thread execution hijacking is a technique used by malware to evade detection by targeting an existing thread of a process and avoiding any noisy process or thread creation operations. This technique allows the malware to run its code within the context of the targeted thread, without creating new processes or threads, which can be easily detected by security software.

During …

SuspendThread Anti-Debugging

Suspending threads is a technique used by malware to disable user-mode debuggers and make it more difficult for security analysts to reverse engineer and analyze the code. This can be achieved by using the SuspendThread function from the kernel32.dll library or the NtSuspendThread function from the NTDLL.DLL library.

The malware can enumerate the threads of a given process, or search …

NtSetInformationThread Anti-Debugging

NtSetInformationThread can be used to hide threads from debuggers using the ThreadHideFromDebugger ThreadInfoClass (0x11 / 17). This is intended to be used by an external process, but any thread can use it on itself.

After the thread is hidden from the debugger, it will continue running but the debugger won’t receive events related to this thread. This thread …