Spoofcall.asm

PUBLIC _spoofer_stub
         
.code
         
_spoofer_stub PROC
    pop r11
    add rsp, 8
    mov rax, [rsp + 24]
            
    mov r10, [rax]
    mov [rsp], r10
            
    mov r10, [rax + 8]
    mov [rax + 8], r11
         
    mov [rax + 16], rbx
    lea rbx, fixup
    mov [rax], rbx
    mov rbx, rax
            
    jmp r10
         
fixup:
    sub rsp, 16
    mov rcx, rbx
    mov rbx, [rcx + 16]
    jmp QWORD PTR [rcx + 8]
_spoofer_stub ENDP
         
END