Injection working!

Author: codeSamuraii

DLLoad/Form1.Designer.cs

@@ -5,7 +5,7 @@ namespace DLLoad
     public partial class MainForm : Form
     {
         private Process selectedProcess;
-        private Stream selectedDll;
+        private string selectedDll;
 
         public MainForm()
         {
@@ -36,11 +36,16 @@ private void btnBrowseDll_Click(object sender, EventArgs e)
         {
             var dialogResult = openDllFileDialog.ShowDialog();
             if (dialogResult == DialogResult.OK)
-                selectedDll = openDllFileDialog.OpenFile();
+                selectedDll = openDllFileDialog.FileName;
             else
                 return;
 
             tbDllPath.Text = openDllFileDialog.FileName;
         }
+
+        private void btnInject_Click(object sender, EventArgs e)
+        {
+            BasicInject.Inject(selectedProcess, selectedDll);
+        }
     }
 }

DLLoad/Form1.cs

@@ -1,3 +1,9 @@
+using System;
+using System.Text;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+
 namespace DLLoad
 {
     internal static class Program
@@ -14,4 +20,51 @@ static void Main()
             Application.Run(new MainForm());
         }
     }
+
+
+    public class BasicInject
+    {
+        [DllImport("kernel32.dll")]
+        public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);
+
+        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
+        public static extern IntPtr GetModuleHandle(string lpModuleName);
+
+        [DllImport("kernel32", CharSet = CharSet.Ansi, ExactSpelling = true, SetLastError = true)]
+        static extern IntPtr GetProcAddress(IntPtr hModule, string procName);
+
+        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
+        static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress, uint dwSize, uint flAllocationType, uint flProtect);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, byte[] lpBuffer, uint nSize, out UIntPtr lpNumberOfBytesWritten);
+
+        [DllImport("kernel32.dll")]
+        static extern IntPtr CreateRemoteThread(IntPtr hProcess, IntPtr lpThreadAttributes, uint dwStackSize, IntPtr lpStartAddress, IntPtr lpParameter, uint dwCreationFlags, IntPtr lpThreadId);
+
+        // privileges
+        const int PROCESS_CREATE_THREAD = 0x0002;
+        const int PROCESS_QUERY_INFORMATION = 0x0400;
+        const int PROCESS_VM_OPERATION = 0x0008;
+        const int PROCESS_VM_WRITE = 0x0020;
+        const int PROCESS_VM_READ = 0x0010;
+
+        // used for memory allocation
+        const uint MEM_COMMIT = 0x00001000;
+        const uint MEM_RESERVE = 0x00002000;
+        const uint PAGE_READWRITE = 4;
+
+        public static int Inject(Process targetProcess, string dllPath)
+        {
+            IntPtr procHandle = OpenProcess(PROCESS_CREATE_THREAD | PROCESS_QUERY_INFORMATION | PROCESS_VM_OPERATION | PROCESS_VM_WRITE | PROCESS_VM_READ, false, targetProcess.Id);
+            IntPtr loadLibraryAddr = GetProcAddress(GetModuleHandle("kernel32.dll"), "LoadLibraryA");
+            IntPtr allocMemAddress = VirtualAllocEx(procHandle, IntPtr.Zero, (uint)((dllPath.Length + 1) * Marshal.SizeOf(typeof(char))), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+
+            UIntPtr bytesWritten;
+            WriteProcessMemory(procHandle, allocMemAddress, Encoding.Default.GetBytes(dllPath), (uint)((dllPath.Length + 1) * Marshal.SizeOf(typeof(char))), out bytesWritten);
+            CreateRemoteThread(procHandle, IntPtr.Zero, 0, loadLibraryAddr, allocMemAddress, 0, IntPtr.Zero);
+
+            return 0;
+        }
+    }
 }