Thread Execution Hijacking
Where this stands
One published detection covers this technique. Every one is unverified — no rule on Siemphony has been executed against real telemetry.
What the technique is
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. 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.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN0822
Detects hijacking of an existing thread (OpenThread) through a behavioral chain involving thread suspension (SuspendThread), memory modification (VirtualAllocEx + WriteProcessMemory), context manipulation (SetThreadContext), and thread resumption—all within another live process's address space (ResumeThread).
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.