Find sigma rule 
Attack: Thread Execution Hijacking
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 malicious code or the path to a DLL. A handle to an existing victim process is first created with native Windows API calls such as OpenThread. At this point the process can be suspended then written to, realigned to the injected code, and resumed via SuspendThread , VirtualAllocEx, WriteProcessMemory, SetThreadContext, then ResumeThread respectively.(Citation: Elastic Process Injection July 2017)
This is very similar to Process Hollowing but targets an existing process rather than creating a process in a suspended state.
Running code in the context of another process may allow access to the process’s memory, system/network resources, and possibly elevated privileges. Execution via Thread Execution Hijacking may also evade detection from security products since the execution is masked under a legitimate process.
MITRE
Tactic
- defense-evasion
- privilege-escalation
technique
- T1055.003
Test : Thread Execution Hijacking
OS
- windows
Description:
This test injects a MessageBox shellcode generated by msfvenom in Notepad.exe using Thread Execution Hijacking. When successful, a message box will appear with the “Atomic Red Team” caption after one or two seconds.
Executor
powershell
Sigma Rule
- proc_access_win_susp_shellcode_injection.yml (id: 250ae82f-736e-4844-a68b-0b5e8cc887da)