Squalr : Squalr Memory Editor – Game Hacking Tool Written In C#

Squalr is performant Memory Editing software that allows users to create and share cheats in their windows desktop games. This includes memory scanning, pointers, x86/x64 assembly injection, and so on.

Squalr achieves fast scans through multi-threading combined with SIMD instructions. See this article: SIMD in .NET. To take advantage of these gains, your CPU needs to have support for SSE, AVX, or AVX-512.

Documentation

You can find detailed documentation on the Wiki. There are three ways to use Squalr:

• Front end GUI
• Scripting API
• Back end NuGet packages

Below is some brief documentation on the NuGet package APIs

Receiving Engine Output

If using the NuGet packages, it is important to hook into the engine’s output to receive logs of events. These are invaluable for diagnosing issues.

using Squalr.Engine.Logging;
…
// Receive logs from the engine
Logger.Subscribe(new EngineLogEvents());
…
class EngineLogEvents : ILoggerObserver
{
public void OnLogEvent(LogLevel logLevel, string message, string innerMessage)
{
Console.WriteLine(message);
Console.WriteLine(innerMessage);
}
}

Attaching The Engine

using Squalr.Engine.OS;
…
IEnumerable processes = Processes.Default.GetProcesses();
// Pick a process. For this example, we are just grabbing the first one.
Process process = processes.FirstOrDefault();
Processes.Default.OpenedProcess = process;

Manipulating Memory

using Squalr.Engine.Memory;
…
Reader.Default.Read(address);
Writer.Default.Write(address);
Allocator.Alloc(address, 256);
IEnumerable regions = Query.GetVirtualPages(requiredProtection, excludedProtection, allowedTypes, startAddress, endAddress);
IEnumerable modules = Query.GetModules();

Assembling/Disassembling

Squalr can assemble and disassemble x86/x64 instructions, leveraging NASM.

using Squalr.Engine.Architecture;
using Squalr.Engine.Architecture.Assemblers;
…
// Perform assembly
AssemblerResult result = Assembler.Default.Assemble(assembly: “mov eax, 5”, isProcess32Bit: true, baseAddress: 0x10000);
Console.WriteLine(BitConverter.ToString(result.Bytes).Replace(“-“, ” “));
// Disassemble the result (we will get the same instructions back)
Instruction[] instructions = Disassembler.Default.Disassemble(bytes: result.Bytes, isProcess32Bit: true, baseAddress: 0x10000);
Console.WriteLine(instructions[0].Mnemonic);

Scanning

Squalr has an API for performing high performance memory scanning:

using Squalr.Engine.Scanning;
using Squalr.Engine.Scanning.Scanners;
using Squalr.Engine.Scanning.Scanners.Constraints;
using Squalr.Engine.Scanning.Snapshots;
…
DataType dataType = DataType.Int32;
// Collect values
TrackableTask valueCollectorTask = ValueCollector.CollectValues(
SnapshotManager.GetSnapshot(Snapshot.SnapshotRetrievalMode.FromActiveSnapshotOrPrefilter, dataType));
// Perform manual scan on value collection complete
valueCollectorTask.CompletedCallback += ((completedValueCollection) =>
{
Snapshot snapshot = completedValueCollection.Result;
// Constraints
ScanConstraintCollection scanConstraints = new ScanConstraintCollection();
scanConstraints.AddConstraint(new ScanConstraint(ScanConstraint.ConstraintType.Equal, 25));
TrackableTask scanTask = ManualScanner.Scan(
snapshot,
allScanConstraints);
SnapshotManager.SaveSnapshot(scanTask.Result);
});
for (UInt64 index = 0; index < snapshot.ElementCount; index++)
{
SnapshotElementIndexer element = snapshot[index];
Object currentValue = element.HasCurrentValue() ? element.LoadCurrentValue() : null;
Object previousValue = element.HasPreviousValue() ? element.LoadPreviousValue() : null;
}

Debugging

// Example: Tracing write events on a float
BreakpointSize size = Debugger.Default.SizeToBreakpointSize(sizeof(float));
CancellationTokenSource cancellationTokenSource = Debugger.Default.FindWhatWrites(0x10000, size, this.CodeTraceEvent);
…
// When finished, cancel the instruction collection
cancellationTokenSource.cancel();
…
private void CodeTraceEvent(CodeTraceInfo codeTraceInfo)
{
Console.WriteLine(codeTraceInfo.Instruction.Address.ToString(“X”));
Console.WriteLine(codeTraceInfo.Instruction.Mnemonic);
}

Recommended Visual Studio Extensions

Reference	Description
XAML Formatter	XAML should be run through this formatter
StyleCop	StyleCop to enforce code conventions. Note that we deviate on some standard conventions. We use the full type name for variables (ex Int32 rather than int). The reasoning is that this is a memory editor, so we prefer to use the type name that is most explicit to avoid coding mistakes.

Build

In order to compile Squalr, you should only need Visual Studio 2017. This should be up to date, we frequently update Squalr to use the latest version of the .NET framework. Here are the important 3rd party libraries that this project uses:

Library	Description
EasyHook	Managed/Unmanaged API Hooking
SharpDisasm	Udis86 Assembler Ported to C#
CsScript	C# Scripting Library
AvalonEdit	Code Editing Library
SharpDX	DirectX Wrapper
CLRMD	.NET Application Inspection Library
AvalonDock	Docking Library
LiveCharts	WPF Charts

Planned Features

Library	Description	Purpose
AsmJit	x86/x64 Assembler	Replace FASM, improve scripting drastically
AsmJit	x86/x64 Assembler	Original C++ project. May port/interop this if the above version does not work (Neither may fully work, and something custom may be needed)
WpfHexEditorControl	Hex Editor	Hex editor / Memory Hex Editor
OpenTK	OpenGL Wrapper	Graphics Injection
SharpDX	DirectX Wrapper	Graphics Injection (Currently using SharpDX just for input)
SharpPCap	Packet Capture	Packet Editor
Packet.Net	Packet Capture	Packet Editor