Reflective code loading executes code from a process's memory instead of loading it as a file-backed module. Examples include executing position-independent code in the current process and loading a .NET assembly from bytes with Assembly.Load. A loader may create a thread, but thread creation is not required by the technique; writes into a different process are process injection (T1055), a separate behavior.
Variant:
Inject raw x64 shellcode into a process
powershell
RESTRICTED_ACCESS_BLUR_MARKER
RESTRICTED_ACCESS_BLUR_MARKER
RESTRICTED_ACCESS_BLUR_MARKER
RESTRICTED_ACCESS_BLUR_MARKER