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@securitygab
Last active October 23, 2023 20:03
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A simple x86 packer that uses APLib,
#########################################
# Created by @kuroi_dotsh - KuroiSH #
# Website: https://dengisan.nl/ #
# E-mail: support@dengisan.nl #
#########################################
;
; The executable is stored in the final section, so that it does not need
; relocations (as we can simply load it over our own headers and pad with
; virtualsize to keep our module running).
; Nothing is needed at runtime, to build a simple script to read the
; attributes from the payload and write to 'packer_constants.inc' and then run
; fasm.
; Doesn't currently support TLS callbacks/handlers
;======= Std ===========
include '%inc%\win32a.inc'
;======= Local =========
include '.\imagehdr.inc'
;=======================
include '.\packer_constants.inc'
format PE GUI 6.0 NX at BASEADDRESS
entry _entry
;=======================================
; Constants
;=======================================
;======== Unpacked loading space =======
section '.bss' data readable writable
;=======================================
VirtualPayload:
.payload db VIRTUALSIZE+1 dup(?)
;======== Packer code ==================
section '.text' code readable executable
;=======================================
_entry:
sub esp, $4
xor edx, edx
invoke GetModuleHandleA,edx
; assert(eax)
mov edi, eax
invoke VirtualProtect,eax,1,PAGE_READWRITE,esp
mov esi, pDecompressed
ccall aP_depack_asm,pPayload,esi
stdcall loadpe
call eax
add esp, $4
invoke ExitProcess,eax
loadpe: ; in esi = file aligned pe
; in edi = dest
; out eax = void (*entrypoint)(void);
push ebx esi edi ebp
push esi ; [esp+4*2] is file base
push edi ; [esp+4*1] is module base
cld
movzx ecx, word [esi+IMAGE_DOS_HEADER.e_cparhdr]
shl ecx, 4
push esi edi
rep movsb
pop edi esi
mov eax, [esi+IMAGE_DOS_HEADER.e_lfanew]
add esi, eax
add edi, eax
mov ebp, esi ; save nt headers*
movzx eax, word [esi+IMAGE_NT_HEADERS.FileHeader.SizeOfOptionalHeader]
lea ecx, [eax+esi+sizeof.IMAGE_FILE_HEADER+4]
mov ebx, ecx ; save section headers*
mov edx, sizeof.IMAGE_SECTION_HEADER
movzx eax, word [esi+IMAGE_NT_HEADERS.FileHeader.NumberOfSections]
push eax
mul edx
xadd eax, ecx ; ecx = sizeof pe headers
rep movsb
pop edx ; number of sections
mov eax, ebx
.loadsec:
mov ecx, [eax+IMAGE_SECTION_HEADER.SizeOfRawData]
mov esi, [eax+IMAGE_SECTION_HEADER.PointerToRawData]
add esi, [esp+4*1]; file base
mov edi, [eax+IMAGE_SECTION_HEADER.VirtualAddress]
add edi, [esp+4*0]; module base
rep movsb ; not guaranteed to not be aligned to 1
add eax, sizeof.IMAGE_SECTION_HEADER
sub edx, 1
jnz .loadsec
; ebp = nt_headers*
; ebx = section_header*
; [esp+0] = module base
; [esp+4] = file base
push ebx
.imports:
lea edi, [ebp+IMAGE_NT_HEADERS.OptionalHeader.DataDirectory+sizeof.IMAGE_DATA_DIRECTORY*IMAGE_DIRECTORY_ENTRY_IMPORT]
mov eax, [edi+IMAGE_DATA_DIRECTORY.Size]
test eax, eax
jz .noimports
mov edi, [edi+IMAGE_DATA_DIRECTORY.VirtualAddress]
test edi, edi
jz .noimports
add edi, [esp+4+4*0] ; to va
.importlibraryloop:
mov eax, [edi+IMAGE_IMPORT_DESCRIPTOR.Characteristics]
test eax, eax
jz .doneimports ; null terminated list
mov eax, [edi+IMAGE_IMPORT_DESCRIPTOR.Name]
add eax, [esp+4+4*0]
invoke LoadLibraryA,eax
mov ebx, eax
mov esi, [edi+IMAGE_IMPORT_DESCRIPTOR.FirstThunk]
add esi, [esp+4+4*0]
; edi = thunk_data*
.importitemloop:
lodsd ; thunk_data is dword union
test eax, eax
jz .importlibrarynext
js .importbyordinal ; hi bit = IMAGE_ORDINAL_FLAG
.importbyname:
add eax, IMAGE_IMPORT_BY_NAME.Name ; skip hint
add eax, [esp+4+4*0]
jmp .importfunction
.importbyordinal:
and eax, $ffff ; hi word must be 0 for getprocaddr
.importfunction:
invoke GetProcAddress,ebx,eax
mov [esi-4], eax ; save item ptr
.importlibrarynext:
add edi, sizeof.IMAGE_IMPORT_DESCRIPTOR
jmp .importlibraryloop
.doneimports:
.noimports:
pop ebx
; ebp = nt_headers*
; ebx = section_header*
; [esp+4] = module base
; [esp+8] = file base
.protect:
; protect headers (r)
sub esp, $4
mov eax, [esp+4]
invoke VirtualProtect,eax,1,PAGE_READONLY,esp
add esp, $4
movzx edi, word [ebp+IMAGE_NT_HEADERS.FileHeader.NumberOfSections]
mov esi, 4
.protectsection:
mov eax, [ebx+IMAGE_SECTION_HEADER.Characteristics]
shr eax, 3*8+5 ; rest of flags are irrelevant (top 3 bits)
; al = 0000`0wre
xor ecx, ecx
mov edx, eax
and edx, $6 ; 0000`0wr0
cmp eax, 6 ; if r && w
cmove edx, esi ; set r/w
xor ecx, ecx
test eax, $1 ; if e
cmovnz ecx, esi ; shift to second nibble
shl edx, cl
; we only care about protection attributes to execute
mov eax, [ebx+IMAGE_SECTION_HEADER.VirtualAddress]
add eax, [esp+4*0]
mov ecx, [ebx+IMAGE_SECTION_HEADER.VirtualSize]
sub esp, 4 ; for old protection (page_readwrite)
invoke VirtualProtect,eax,ecx,edx,esp
add esp, 4
.protectnext:
add ebx, sizeof.IMAGE_SECTION_HEADER
sub edi, 1
jnz .protectsection
; tls
.callep:
mov eax, [ebp+IMAGE_NT_HEADERS.OptionalHeader.AddressOfEntryPoint]
add eax, [esp+4*0]
add esp, 4*2 ; saved module and file base
pop ebx esi edi ebp
ret
;;
;; aPLib compression library - the smaller the better :)
;;
;; fasm assembler depacker
;;
;; Copyright (c) 1998-2009 by Joergen Ibsen / Jibz
;; All Rights Reserved
;;
;; http://www.ibsensoftware.com/
;;
aP_depack_asm:
; aP_depack_asm(const void *source, void *destination)
_ret$ equ 7*4
_src$ equ 8*4 + 4
_dst$ equ 8*4 + 8
pushad
mov esi, [esp + _src$] ; C calling convention
mov edi, [esp + _dst$]
cld
mov dl, 80h
xor ebx,ebx
literal:
movsb
mov bl, 2
nexttag:
call getbit
jnc literal
xor ecx, ecx
call getbit
jnc codepair
xor eax, eax
call getbit
jnc shortmatch
mov bl, 2
inc ecx
mov al, 10h
.getmorebits:
call getbit
adc al, al
jnc .getmorebits
jnz domatch
stosb
jmp nexttag
codepair:
call getgamma_no_ecx
sub ecx, ebx
jnz normalcodepair
call getgamma
jmp domatch_lastpos
shortmatch:
lodsb
shr eax, 1
jz donedepacking
adc ecx, ecx
jmp domatch_with_2inc
normalcodepair:
xchg eax, ecx
dec eax
shl eax, 8
lodsb
call getgamma
cmp eax, 32000
jae domatch_with_2inc
cmp ah, 5
jae domatch_with_inc
cmp eax, 7fh
ja domatch_new_lastpos
domatch_with_2inc:
inc ecx
domatch_with_inc:
inc ecx
domatch_new_lastpos:
xchg eax, ebp
domatch_lastpos:
mov eax, ebp
mov bl, 1
domatch:
push esi
mov esi, edi
sub esi, eax
rep movsb
pop esi
jmp nexttag
getbit:
add dl, dl
jnz .stillbitsleft
mov dl, [esi]
inc esi
adc dl, dl
.stillbitsleft:
ret
getgamma:
xor ecx, ecx
getgamma_no_ecx:
inc ecx
.getgammaloop:
call getbit
adc ecx, ecx
call getbit
jc .getgammaloop
ret
donedepacking:
sub edi, [esp + _dst$]
mov [esp + _ret$], edi ; return unpacked length in eax
popad
ret
;=======================================
; reloc data directory (.reloc)
; removed by builder
;=======================================
;data fixups
; auto filled
;end data
;=======================================
; import data directory (.idata)
;=======================================
data import
library kernel32,'kernel32.dll',\
user32,'user32.dll'
import kernel32,\
ExitProcess,'ExitProcess',\
GetModuleHandleA,'GetModuleHandleA',\
GetProcAddress,'GetProcAddress',\
LoadLibraryA,'LoadLibraryA',\
VirtualProtect,'VirtualProtect'
; random shit
import user32,\
CreateWindowA,'CreateWindowA',\
DispatchMessage,'DispatchMessage',\
RegisterClassExA,'RegisterClassExA',\
ShowWindow,'ShowWindow',\
TranslateMessage,'TranslateMessage'
end data
;======== PE File ======================
section '.data' data readable writeable
;=======================================
CompressedHeader:
.RawSize dd RAWSIZE
.VirtualSize dd VIRTUALSIZE
pPayload:
file TARGET_FILE
pDecompressed db RAWSIZE + 1 dup(?)
@BugEmir
Copy link

BugEmir commented Jun 1, 2022

https://github.com/vgris/Hazel/blob/master/HAZEL.ASM

why u snatching code bro. living the poser life :*(

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