unicorn/bindings/dotnet/UnicornSamples/ShellcodeSample.cs
2016-01-04 11:30:11 +01:00

200 lines
7 KiB
C#

using Gee.External.Capstone;
using Gee.External.Capstone.X86;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using UnicornManaged;
using UnicornManaged.Const;
namespace UnicornSamples
{
internal class ShellcodeSample
{
private const Int64 ADDRESS = 0x1000000;
public static void X86Code32Self()
{
Byte[] X86_CODE32_SELF =
{
0xeb, 0x1c, 0x5a, 0x89, 0xd6, 0x8b, 0x02, 0x66, 0x3d, 0xca, 0x7d, 0x75, 0x06, 0x66, 0x05, 0x03, 0x03,
0x89, 0x02, 0xfe, 0xc2, 0x3d, 0x41, 0x41, 0x41, 0x41, 0x75, 0xe9, 0xff, 0xe6, 0xe8, 0xdf, 0xff, 0xff,
0xff, 0x31, 0xd2, 0x6a, 0x0b, 0x58, 0x99, 0x52, 0x68, 0x2f, 0x2f, 0x73, 0x68, 0x68, 0x2f, 0x62, 0x69,
0x6e, 0x89, 0xe3, 0x52, 0x53, 0x89, 0xe1, 0xca, 0x7d, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41
};
Run(X86_CODE32_SELF);
}
public static void X86Code32()
{
Byte[] X86_CODE32 =
{
0xeb, 0x19, 0x31, 0xc0, 0x31, 0xdb, 0x31, 0xd2, 0x31, 0xc9, 0xb0, 0x04, 0xb3, 0x01, 0x59, 0xb2, 0x05,
0xcd, 0x80, 0x31, 0xc0, 0xb0, 0x01, 0x31, 0xdb, 0xcd, 0x80, 0xe8, 0xe2, 0xff, 0xff, 0xff, 0x68, 0x65,
0x6c, 0x6c, 0x6f
};
Run(X86_CODE32);
}
private static void Run(Byte[] code)
{
Console.WriteLine();
var stackTrace = new StackTrace();
var stackFrame = stackTrace.GetFrames()[1];
var methodName = stackFrame.GetMethod().Name;
Console.WriteLine("*** Start: " + methodName);
RunTest(code, ADDRESS);
Console.WriteLine("*** End: " + methodName);
Console.WriteLine();
}
private static void RunTest(Byte[] code, Int64 address)
{
try
{
using (var u = new Unicorn(Common.UC_ARCH_X86, Common.UC_MODE_32))
using(var disassembler = CapstoneDisassembler.CreateX86Disassembler(DisassembleMode.Bit32))
{
Console.WriteLine("Unicorn version: {0}", u.Version());
// map 2MB of memory for this emulation
u.MemMap(address, 2 * 1024 * 1024, Common.UC_PROT_ALL);
// write machine code to be emulated to memory
u.MemWrite(address, code);
//var read = new Byte[code.Length];
//u.MemRead(address, read);
//Console.WriteLine(Disassemble(disassembler, code));//
// initialize machine registers
u.RegWrite(X86.UC_X86_REG_ESP, Utils.Int64ToBytes(address + 0x200000));
var regv = new Byte[4];
u.RegRead(X86.UC_X86_REG_ESP, regv);
// tracing all instructions by having @begin > @end
u.AddCodeHook((uc, addr, size, userData) => CodeHookCallback(disassembler, uc, addr, size, userData), 1, 0);
// handle interrupt ourself
u.AddInterruptHook(InterruptHookCallback);
// handle SYSCALL
u.AddSyscallHook(SyscallHookCallback);
Console.WriteLine(">>> Start tracing code");
// emulate machine code in infinite time
u.EmuStart(address, address + code.Length, 0u, 0u);
Console.WriteLine(">>> Emulation Done!");
}
}
catch (UnicornEngineException ex)
{
Console.Error.WriteLine("Emulation FAILED! " + ex.Message);
}
}
private static void CodeHookCallback(
CapstoneDisassembler<X86Instruction, X86Register, X86InstructionGroup,X86InstructionDetail> disassembler,
Unicorn u,
Int64 addr,
Int32 size,
Object userData)
{
Console.Write("[+] 0x{0}: ", addr.ToString("X"));
var eipBuffer = new Byte[4];
u.RegRead(X86.UC_X86_REG_EIP, eipBuffer);
var effectiveSize = Math.Min(16, size);
var tmp = new Byte[effectiveSize];
u.MemRead(addr, tmp);
var sb = new StringBuilder();
foreach (var t in tmp)
{
sb.AppendFormat("{0} ", (0xFF & t).ToString("X"));
}
Console.Write("{0,-20}", sb);
Console.WriteLine(Utils.Disassemble(disassembler, tmp));
}
private static void SyscallHookCallback(Unicorn u, Object userData)
{
var eaxBuffer = new Byte[4];
u.RegRead(X86.UC_X86_REG_EAX, eaxBuffer);
var eax = Utils.ToInt(eaxBuffer);
Console.WriteLine("Syscall >>> EAX = 0x{0}", eax.ToString("X"));
u.EmuStop();
}
private static void InterruptHookCallback(Unicorn u, Int32 intNumber, Object userData)
{
// only handle Linux syscall
if (intNumber != 0x80)
{
return;
}
var eaxBuffer = new Byte[4];
var eipBuffer = new Byte[4];
u.RegRead(X86.UC_X86_REG_EAX, eaxBuffer);
u.RegRead(X86.UC_X86_REG_EIP, eipBuffer);
var eax = Utils.ToInt(eaxBuffer);
var eip = Utils.ToInt(eipBuffer);
switch (eax)
{
default:
Console.WriteLine("Interrupt >>> 0x{0} num {1}, EAX=0x{2}", eip.ToString("X"), intNumber.ToString("X"), eax.ToString("X"));
break;
case 1: // sys_exit
Console.WriteLine("Interrupt >>> 0x{0} num {1}, SYS_EXIT", eip.ToString("X"), intNumber.ToString("X"));
u.EmuStop();
break;
case 4: // sys_write
// ECX = buffer address
var ecxBuffer = new Byte[4];
// EDX = buffer size
var edxBuffer = new Byte[4];
u.RegRead(X86.UC_X86_REG_ECX, ecxBuffer);
u.RegRead(X86.UC_X86_REG_EDX, edxBuffer);
var ecx = Utils.ToInt(ecxBuffer);
var edx = Utils.ToInt(edxBuffer);
// read the buffer in
var size = Math.Min(256, edx);
var buffer = new Byte[size];
u.MemRead(ecx, buffer);
var content = Encoding.Default.GetString(buffer);
Console.WriteLine(
"Interrupt >>> 0x{0}: num {1}, SYS_WRITE. buffer = 0x{2}, size = , content = '{3}'",
eip.ToString("X"),
ecx.ToString("X"),
edx.ToString("X"),
content);
break;
}
}
}
}