Running executable from memory - c#

I'm trying to run an executable directly from a byte[] representation of this executable as a resource in C#.
So basically i want to run a byte[] of an PE directly without touching the harddisk.
The code I'm using for this used to work but it doesn't anymore.
The code creates a process with a frozen main thread, changes the whole process data and finally resumes it so it runs the byte[] of the PE. But it seems like the process dies if the thread is resumed, i don't really know whats wrong.
So here is the code in a pastebin because its too long for here i guess...
http://pastebin.com/18hfFvHm
EDIT:
I want to run non-managed code !
Any PE File ...

Here is some code to execute native code (inside a byte array). Note that it is not exactly what you are asking for (it's not a PE file bytes, but a native procedure bytes ie. in assembly language)
using System;
using System.Runtime.InteropServices;
namespace Native
{
class Program
{
private const UInt32 MEM_COMMIT = 0x1000;
private const UInt32 PAGE_EXECUTE_READWRITE = 0x40;
private const UInt32 MEM_RELEASE = 0x8000;
[DllImport("kernel32")] private static extern UInt32 VirtualAlloc(UInt32 lpStartAddr, UInt32 size, UInt32 flAllocationType, UInt32 flProtect);
[DllImport("kernel32")] private static extern bool VirtualFree(IntPtr lpAddress, UInt32 dwSize, UInt32 dwFreeType);
[DllImport("kernel32")]
private static extern IntPtr CreateThread(
UInt32 lpThreadAttributes,
UInt32 dwStackSize,
UInt32 lpStartAddress,
IntPtr param,
UInt32 dwCreationFlags,
ref UInt32 lpThreadId
);
[DllImport("kernel32")] private static extern bool CloseHandle(IntPtr handle);
[DllImport("kernel32")] private static extern UInt32 WaitForSingleObject(IntPtr hHandle, UInt32 dwMilliseconds);
static void Main(string[] args)
{
byte[] nativecode = new byte[] { /* here your native bytes */ };
UInt32 funcAddr = VirtualAlloc(0, (UInt32)nativecode.Length, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
Marshal.Copy(nativecode, 0, (IntPtr)(funcAddr), nativecode.Length);
IntPtr hThread = IntPtr.Zero;
UInt32 threadId = 0;
hThread = CreateThread(0, 0, funcAddr, IntPtr.Zero, 0, ref threadId);
WaitForSingleObject(hThread, 0xFFFFFFFF);
CloseHandle(hThread);
VirtualFree((IntPtr)funcAddr, 0, MEM_RELEASE);
}
}
}

This code may help:
Dynamic Process Forking of Portable Executable by Vrillon / Venus:
http://forum.gamedeception.net/threads/16557-Process-Forking-Running-Process-From-Memory

Leaving this here for everyone.
USE RUNPE
Look it up, works great :) I suggest self inject.

i found that sample, hope it will be useful for you.
http://www.cyberhackers.mybbnew.com/showthread.php?tid=178

I haven't tried this, so it's purely specutive, but I believe you want to load in into the AppDomain:
byte[] myAssm = ...
AppDomain.CurrentDomain.Load(myAssm);
AppDomain.CurrentDomain.ExecuteAssemblyByName(nameOfMyAssm);

I'm not sure if this will be much help, but here is where I answer running straight x86/x64 assembly opcodes from a C# program.

I believe your problem is that you are asking for a security hole.
To run any PE, you are asking -- "Let my secure/managed .NET app run an insecure/unmanaged app -- In a way which bypasses normal security".
Let's say I run you application (which I assume is secure). I've not given it permission to write to sensitive folder; it can't overrun buffers; it can't touch my win32 mode code. You then build, byte-by-byte, a malicious application in a byts[], and launch that. Where does Windows step in to ask me if I want to let this happen? And what does that warning say ? "Is that array of bytes from a trusted source?"

In theory, if you are running full trust, there is nothing stopping you from doing CreateProcess on rundll32.exe, unmapping rundll32.exe, and performing the initial EXE load yourself.
The way I'd go about it is inject a thread into the target process that does the work in an unmanaged way. Yes, this means piles of relocatable assembly.
The general idea is to call LdrUnloadModule to get rid of rundll32.exe, call LdrLoadModule to load the EXE, fixup the load chain to indicate it was loaded first, then restart the main thread.
Good luck to you.

Repost of Load an EXE file and run it from memory
Not tested but looks like to be the only way to do this (2nd answer)

Related

Using an unmanaged DLL with C#

I'm using a Silicon Labs VCP (CP2105) under Windows (7/8/10) and I am trying to obtain some info from it using the Silicon Labs runtime DLL - which is unmanaged.
This is my implementation:
[DllImport("CP210xRuntime.dll")]
private static extern Int32 CP210xRT_GetDeviceProductString(IntPtr handle, IntPtr bfPtr, ref uint len, bool convert);
public static Int32 GetProduct(IntPtr handle)
{
var buff = new char[100];
GCHandle hnd = GCHandle.Alloc(buff);
IntPtr bfPtr = (IntPtr)hnd;
uint bytesRead = 0;
var r = CP210xRT_GetDeviceProductString(handle, bfPtr, ref bytesRead, true);
hnd.Free();
return r;
}
I am getting the device handle for the ports using:
[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr CreateFile(
string FileName,
uint DesiredAccess,
uint ShareMode,
IntPtr SecurityAttributes,
uint CreationDisposition,
uint FlagsAndAttributes,
IntPtr hTemplateFile
);
When I run this it works - of sorts, that is to say the return value is 0 which, according to the Silicon Labs docs, indicates all is well, and I have confirmed this by using a handle to another device and I got 3 back, which confirms invalid handle.
The bytesRead ref value is also ammended as expected to 36 which is what the length of the product name should be. But the buff array never fills with any data (just to be sure I have written values to each element as well but they dont change). If I leave the program running the whole thing throws an exception:
Managed Debugging Assistant 'FatalExecutionEngineError' has detected a problem in********
Additional information: The runtime has encountered a fatal error. The address of the error was at 0x70338780, on thread 0x1f5c. The error code is 0xc0000005. This error may be a bug in the CLR or in the unsafe or non-verifiable portions of user code. Common sources of this bug include user marshaling errors for COM-interop or PInvoke, which may corrupt the stack.
This is also the program does, if I comment out the line where I call the function from the dll - the program does not fail.
I'm not massively familar with invoke unmanged code using C# so if someone could help me out with where I am going wrong / point me in the right direction I would be most grateful!
This is from the Silicon Labs Docs:
CP210x_STATUS CP210xRT_GetDeviceProductString(HANDLE cyHandle, 
LPVOID lpProduct, LPBYTE lpbLength, BOOL bConvertToASCII = TRUE)

P/Invoke problems with basic CRT functions (i.e., putchar, puts)

I've noticed something very strange. I was trying to call the CRT function "putchar", and was unable to get it to work. So I double-checked that I wasn't missing something, and I copied the code directly from the P/Invoke tutorial on MSDN to see if it worked.
http://msdn.microsoft.com/en-us/library/aa288468%28VS.71%29.aspx
You'll notice that they import "puts".
So I tested the exact code copied from MSDN. It didn't work! So now I got frustrated. I've never had this problem before.
Then I just so happened to run WITHOUT debugging (hit ctrl+f5), and it worked! I tested other functions which output to the console too, and none of them work when debugging but all work when not debugging.
I then wrote a simple C dll which exports a function called "PrintChar(char c)". When I call that function from C#, it works even if I'm debugging or not, without any problems.
What is the deal with this?
The Visual Studio hosting process is capable of redirecting console output to the Output window. How exactly it manages to do this is not documented at all, but it gets in the way here. It intercepts the WriteFile() call that generates the output of puts().
Project + Properties, Debug tab, untick "Enable the Visual Studio hosting process". On that same page, enabling unmanaged debugging also fixes the problem.
It's a bad example, using the C-Runtime Library DLL to call puts. Keep reading the tutorial as there is good info there, but try making Win32 API calls instead.
Here is a better introduction to p/invoke: http://msdn.microsoft.com/en-us/magazine/cc164123.aspx
It's old, but the information is still good.
Edited
My explaination was wrong.
I went looking for a correct explaination and I discovered that the C-Runtime puts method and the .NET Framework Console.Write method differ in how they write to the console (Console.Write works where the p/invoke to puts does not). I thought maybe the answer was in there, so I whipped up this demonstration:
using System;
using System.Diagnostics;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
class Program
{
public static void Main()
{
int written;
string outputString = "Hello, World!\r\n";
byte[] outputBytes = Encoding.Default.GetBytes(outputString);
//
// This is the way the C-Runtime Library method puts does it
IntPtr conOutHandle = CreateFile("CONOUT$", 0x40000000, FileShare.ReadWrite, IntPtr.Zero, FileMode.Open, 0, IntPtr.Zero);
WriteConsole(conOutHandle, outputBytes, outputString.Length, out written, IntPtr.Zero);
//
// This is the way Console.Write does it
IntPtr stdOutputHandle = GetStdHandle(STD_OUTPUT_HANDLE);
WriteFile(stdOutputHandle, outputBytes, outputBytes.Length, out written, IntPtr.Zero);
// Pause if running under debugger
if (Debugger.IsAttached)
{
Console.Write("Press any key to continue . . . ");
Console.ReadKey();
}
}
const int STD_OUTPUT_HANDLE = -11;
[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr GetStdHandle(int nStdHandle);
[DllImport("kernel32.dll", SetLastError = true)]
static extern int WriteFile(IntPtr handle, [In] byte[] bytes, int numBytesToWrite, out int numBytesWritten, IntPtr mustBeZero);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern IntPtr CreateFile(string lpFileName, int dwDesiredAccess, FileShare dwShareMode, IntPtr securityAttrs, FileMode dwCreationDisposition, int dwFlagsAndAttributes, IntPtr hTemplateFile);
[DllImport("kernel32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
static extern bool WriteConsole(IntPtr hConsoleOutput, [In] byte[] lpBuffer, int nNumberOfCharsToWrite, out int lpNumberOfCharsWritten, IntPtr mustBeZero);
}
Both of those successfully output under the debugger, even with the hosting process enabled. So that is a dead end.
I wanted to share it in case it leads someone else to figuring out why it happens -- Hans?

How to open a file when file handle number is known?

I open a file in C# with FileStream, and I got the file handle number with this line:
IntPtr file_handle = fs.SafeFileHandle.DangerousGetHandle();
Now I want to pass this handle to C++ code and use this handle value to access the file. Is this possible? How to open a file with merely a file handle in C++?
Thanks.
Update
I use C# to P/Invoke into a C++ Win32 DLL(not a COM DLL). I open the file in C# as FileStream, and pass the handle to the C++. Here is some of my code in the C++ DLL:
extern "C" __declspec(dllexport)void read_file(HANDLE file_handle)
{
char buffer[64];
::printf("\nfile = %d\n",file_handle);
if(::ReadFile(file_handle,buffer,32,NULL,NULL))
{
for(int i=0;i<32;i++)
cout<<buffer[i]<<endl;
}
else
cout<<"error"<<endl;
}
And here is my C# code:
[DllImport("...",EntryPoint = "read_file", CharSet = CharSet.Auto)]
public static extern void read_file(IntPtr file_handle_arg);
But I get this error:
Unhandled Exception: System.AccessViolationException: Attempted to read or write
protected memory. This is often an indication that other memory is corrupt.
Thanks.
You can use win32 calls, the same way the filestream/file constructors do (via p/invoke).
Cracking it open in .NET Reflector, it looks like it is using this function:
[DllImport("kernel32.dll", CharSet=CharSet.Auto, SetLastError=true)]
private static extern SafeFileHandle CreateFile(
string lpFileName,
int dwDesiredAccess,
FileShare dwShareMode,
SECURITY_ATTRIBUTES securityAttrs,
FileMode dwCreationDisposition,
int dwFlagsAndAttributes,
IntPtr hTemplateFile);
Here is an official reference:
http://msdn.microsoft.com/en-us/library/aa363858(VS.85).aspx
This is just to open the file, though, as you asked when you said:
How to open a file with merely a file handle in C++
If you want to read an already open file, you might have more trouble. I'm not sure. You might be able to use this function:
[DllImport("kernel32.dll", SetLastError=true)]
internal static extern unsafe int ReadFile(
SafeFileHandle handle,
byte* bytes,
int numBytesToRead,
IntPtr numBytesRead_mustBeZero,
NativeOverlapped* overlapped
);
http://msdn.microsoft.com/en-us/library/aa365467(v=VS.85).aspx
That entirely depends -- but it's unlikely that you will be able to do this. I'm assuming that your C# code and C++ code are running in different processes -- if you're in the same process you should just be able to marshall over the IntPtr over as a HANDLE.
The problem is that file handles are specific to a process -- you won't be able to use that handle in another process.
That said, you're probably better off:
Passing the name of the file to the C++ code and opening it there
Passing the data actually contained whithin the file to the C++ and dealing with it there.
If the C++ code is C++/CLI, then don't bother with the handle at all. Just pass the FileStream object directly to your C++ code.
If the C++ is native code, then you can use the file handle anywhere you'd normally use a Windows HANDLE value for files, such as ReadFile and WriteFile. You wouldn't use the handle to open a file because it's already open. If you want another copy of the handle, or if you want to give the handle to another process, then use DuplicateHandle. If you need to the value with POSIX-like functions like _read and _write, then call _open_osfhandle to get a file descriptor. You can wrap the file descriptor into a C FILE* stream with _fdopen.
Turns out the title isn't really what the OP was after.
But if someone ever really needs to do this (say: Re-opening a file with different permissions), you can probably use a combination of GetFileInformationByHandle to get the File ID and OpenFileById.
FWIW.

Referencing unmanaged librararies from managed code, adventages and disadvantages?

HI all,
I would like to call from my C# code, unamanaged library functions like presented below. There are two options and the both works. In this moment "Beep" function is simple and have no input/output parameters, pointers, references... I am wondering in more complex cases what would be adventages and disadvantage of both approches ?
Thanks,
Milan.
[DllImport("kernel32.dll")]
public static extern bool Beep(uint iFreq, uint iDuration);
public void TestBeep()
{
Beep(300, 3000);
}
internal delegate bool DelegBeep(uint iFreq, uint iDuration);
[DllImport("kernel32.dll")]
internal static extern IntPtr LoadLibrary(String dllname);
[DllImport("kernel32.dll")]
internal static extern IntPtr GetProcAddress(IntPtr hModule, String procName);
public void BeepIt()
{
IntPtr kernel32 = LoadLibrary("Kernel32.dll");
IntPtr procBeep = GetProcAddress(kernel32, "Beep");
DelegBeep delegBeep = Marshal.GetDelegateForFunctionPointer(procBeep, typeof(DelegBeep)) as DelegBeep;
delegBeep(50, 1000);//Hz,ms
}
Your second one is much more complicated than the first but achieves the same thing in this case.
If the name of the DLL and the name of the function are known at compile time, then stick with the first approach. If you don't know the name of the DLL and/or function until run time then the LoadLibary/GetProcAddress approach is your only option.
The P/Invoke marshaller finds an entrypoint in a DLL by using LoadLibrary() and GetProcAddress(). And knows how to convert a C# declaration to the equivalent of a delegate declaration.
Doing this yourself has no advantage beyond maybe a wee bit of efficiency. Which you'd better measure, it is no slamdunk.

Determining type of running application (.NET)

How can I determine if the running application is a Windows Forms or a Console application?
You can't do this reliably. For example, start a new project from the Windows Forms Application project template. Project + Properties, change Output Type to "Console Application". Press F5 to see what that looks like. While every reasonable test will say it is a console mode application, it is very much a WF app.
The opposite is true as well, merely the presence of System.Windows.Forms.dll doesn't make it a WF app. A console app might use it to display a MessageBox for example.
Furthermore, it could be neither. Your code might be called by a service.
Punt this problem, the author of the app never has a problem telling you what your code should do. Add a property to your class to allow her to do so.
p/invoke:
[DllImport("shell32.dll")]
private static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes, ref SHFILEINFO psfi, uint cbSizeFileInfo, uint uFlags);
Struct:
[StructLayout(LayoutKind.Sequential)]
private struct SHFILEINFO
{
public IntPtr hIcon;
public IntPtr iIcon;
public uint dwAttributes;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=260)]
public string szDisplayName;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=80)]
public string szTypeName;
}
Method:
private static bool IsWindowsApplication(string fileName)
{
SHFILEINFO psfi = new SHFILEINFO();
switch (((int) SHGetFileInfo(fileName, 0, ref psfi, (uint) Marshal.SizeOf(psfi), 0x2000)))
{
case 0:
return false;
case 0x4550:
return false;
case 0x5a4d:
return false;
}
return true;
}
If the above method returns false, it's a console application.
-Oisin
If it doesn't need to be done programmatically you could maybe use a program like ProcessExplorer and see if the System.Winforms.dll is loaded. I don't think this is foolproof but it may be a start.
One option might be to check if System.Windows.Forms.Application.OpenForms contains any elements.
Another option might be to check whether Console.Title or Console.WindowTop throws an exception (it would if no console window is open).
EDIT
However, note that an application may have a console window and a form open at the same time... What kind of application is it then?

Categories