Memory Execution of File Stored in Resource

posted 19 Dec 2009, 16:17 by Delphi Basics   [ updated 8 Mar 2010, 15:51 ]
Memory execution example by KriPpler

This is a little example I made for a project Im working
on that protects an executable file by wrapping it within a
stub files resource and running it directly in memory. This
is nice for when you want to manipulate data without writing
it to disk.

Credits:
Aphex : (CreateProcessEx function)

program PrjRes2Mem;

{$APPTYPE CONSOLE}
{$R 'data.res' 'data.rc'}

uses
  windows;

type
  TSections = array [0..0] of TImageSectionHeader;

function GetAlignedSize(Size: dword; Alignment: dword): dword;
begin
  if ((Size mod Alignment) = 0) then
  begin
    Result := Size;
  end
  else
  begin
    Result := ((Size div Alignment) + 1) * Alignment;
  end;
end;

function ImageSize(Image: pointer): dword;
var
  Alignment: dword;
  ImageNtHeaders: PImageNtHeaders;
  PSections: ^TSections;
  SectionLoop: dword;
begin
  ImageNtHeaders := pointer(dword(dword(Image)) + dword(PImageDosHeader(Image)._lfanew));
  Alignment := ImageNtHeaders.OptionalHeader.SectionAlignment;
  if ((ImageNtHeaders.OptionalHeader.SizeOfHeaders mod Alignment) = 0) then
  begin
    Result := ImageNtHeaders.OptionalHeader.SizeOfHeaders;
  end
  else
  begin
    Result := ((ImageNtHeaders.OptionalHeader.SizeOfHeaders div Alignment) + 1) * Alignment;
  end;
  PSections := pointer(pchar(@(ImageNtHeaders.OptionalHeader)) + ImageNtHeaders.FileHeader.SizeOfOptionalHeader);
  for SectionLoop := 0 to ImageNtHeaders.FileHeader.NumberOfSections - 1 do
  begin
    if PSections[SectionLoop].Misc.VirtualSize <> 0 then
    begin
      if ((PSections[SectionLoop].Misc.VirtualSize mod Alignment) = 0) then
      begin
        Result := Result + PSections[SectionLoop].Misc.VirtualSize;
      end
      else
      begin
        Result := Result + (((PSections[SectionLoop].Misc.VirtualSize div Alignment) + 1) * Alignment);
      end;
    end;
  end;
end;

procedure CreateProcessEx(FileMemory: pointer);
var
  BaseAddress, Bytes, HeaderSize, InjectSize,  SectionLoop, SectionSize: dword;
  Context: TContext;
  FileData: pointer;
  ImageNtHeaders: PImageNtHeaders;
  InjectMemory: pointer;
  ProcInfo: TProcessInformation;
  PSections: ^TSections;
  StartInfo: TStartupInfo;
begin
  ImageNtHeaders := pointer(dword(dword(FileMemory)) + dword(PImageDosHeader(FileMemory)._lfanew));
  InjectSize := ImageSize(FileMemory);
  GetMem(InjectMemory, InjectSize);
  try
    FileData := InjectMemory;
    HeaderSize := ImageNtHeaders.OptionalHeader.SizeOfHeaders;
    PSections := pointer(pchar(@(ImageNtHeaders.OptionalHeader)) + ImageNtHeaders.FileHeader.SizeOfOptionalHeader);
    for SectionLoop := 0 to ImageNtHeaders.FileHeader.NumberOfSections - 1 do
    begin
      if PSections[SectionLoop].PointerToRawData < HeaderSize then HeaderSize := PSections[SectionLoop].PointerToRawData;
    end;
    CopyMemory(FileData, FileMemory, HeaderSize);
    FileData := pointer(dword(FileData) + GetAlignedSize(ImageNtHeaders.OptionalHeader.SizeOfHeaders, ImageNtHeaders.OptionalHeader.SectionAlignment));
    for SectionLoop := 0 to ImageNtHeaders.FileHeader.NumberOfSections - 1 do
    begin
      if PSections[SectionLoop].SizeOfRawData > 0 then
      begin
        SectionSize := PSections[SectionLoop].SizeOfRawData;
        if SectionSize > PSections[SectionLoop].Misc.VirtualSize then SectionSize := PSections[SectionLoop].Misc.VirtualSize;
        CopyMemory(FileData, pointer(dword(FileMemory) + PSections[SectionLoop].PointerToRawData), SectionSize);
        FileData := pointer(dword(FileData) + GetAlignedSize(PSections[SectionLoop].Misc.VirtualSize, ImageNtHeaders.OptionalHeader.SectionAlignment));
      end
      else
      begin
        if PSections[SectionLoop].Misc.VirtualSize <> 0 then FileData := pointer(dword(FileData) + GetAlignedSize(PSections[SectionLoop].Misc.VirtualSize, ImageNtHeaders.OptionalHeader.SectionAlignment));
      end;
    end;
    ZeroMemory(@StartInfo, SizeOf(StartupInfo));
    ZeroMemory(@Context, SizeOf(TContext));
    CreateProcess(nil, pchar(ParamStr(0)), nil, nil, False, CREATE_SUSPENDED, nil, nil, StartInfo, ProcInfo);
    Context.ContextFlags := CONTEXT_FULL;
    GetThreadContext(ProcInfo.hThread, Context);
    ReadProcessMemory(ProcInfo.hProcess, pointer(Context.Ebx + 8), @BaseAddress, 4, Bytes);
    VirtualAllocEx(ProcInfo.hProcess, pointer(ImageNtHeaders.OptionalHeader.ImageBase), InjectSize, MEM_RESERVE or MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    WriteProcessMemory(ProcInfo.hProcess, pointer(ImageNtHeaders.OptionalHeader.ImageBase), InjectMemory, InjectSize, Bytes);
    WriteProcessMemory(ProcInfo.hProcess, pointer(Context.Ebx + 8), @ImageNtHeaders.OptionalHeader.ImageBase, 4, Bytes);
    Context.Eax := ImageNtHeaders.OptionalHeader.ImageBase + ImageNtHeaders.OptionalHeader.AddressOfEntryPoint;
    SetThreadContext(ProcInfo.hThread, Context);
    ResumeThread(ProcInfo.hThread);
  finally
    FreeMemory(InjectMemory);
  end;
end;

procedure ResourceToMem;
var
  ResInfo: HRSRC;
  ResSize: LongWord;
  Handle: THandle;
  ResData: Pointer;
begin

  //Locate our resource information from within the resource data
  ResInfo := FindResource(SysInit.HInstance, pchar('a01'), RT_RCDATA);

  if ResInfo <> 0 then
  begin
    //Get the size of our resource information
    ResSize := SizeofResource(SysInit.HInstance, ResInfo);
    if ResSize <> 0 then
    begin
      //Get the handle to our resource information
      Handle := LoadResource(SysInit.HInstance, ResInfo);
      if Handle <> 0 then
      begin
        //Store our data into the resource
        ResData := LockResource(Handle);

        //Execute it!
        createprocessex(ResData);
      end;
    end;
end;

end;

begin
    ResourceToMem;
end.

A PE file should be stored in resources under the name 'a01' for this example to work.

Source: http://www.coderprofile.com/networks/source-codes/138/execute-resource-directly-in-memory

ċ
res2mem.rar
(46k)
Delphi Basics,
8 Mar 2010, 15:51
Comments