v1.4: Block Claude from writing to the Desktop and AppData

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ClaudeRunner.cs

@@ -220,6 +220,8 @@ namespace QuickClaude
             Finished?.Invoke(error);
         }
 
+        // File writes also go through a guard hook ("QuickClaude.exe --guard-write") that blocks the
+        // Desktop and AppData, where OpenRules lets things open without asking.
         // Shell commands go through QuickClaude's own confirm box: a PreToolUse hook that runs
         // "QuickClaude.exe --confirm" (exec form, so no shell quoting). The dialog denies after
         // 2 minutes; the hook timeout is a bit longer so Claude Code never cuts it off first.
@@ -237,6 +239,12 @@ namespace QuickClaude
                         {
                             matcher = "Bash|PowerShell|Monitor", // Monitor also runs shell commands
                             hooks = new[] { new { type = "command", command = exe, args = new[] { "--confirm" }, timeout = 150 } }
+                        },
+                        new
+                        {
+                            // Never lets Claude write to the Desktop or AppData (see WriteGuard)
+                            matcher = "Write|Edit|MultiEdit|NotebookEdit",
+                            hooks = new[] { new { type = "command", command = exe, args = new[] { "--guard-write" }, timeout = 30 } }
                         }
                     }
                 }

Program.cs

@@ -12,6 +12,8 @@ namespace QuickClaude
         {
             // Run as Claude Code's shell-command confirm hook (separate short-lived process)
             if (Array.IndexOf(args, "--confirm") >= 0) return ConfirmHook.Run();
+            // Run as Claude Code's file-write guard hook (see WriteGuard)
+            if (Array.IndexOf(args, "--guard-write") >= 0) return WriteGuard.Run();
 
             using var mutex = new Mutex(true, "QuickClaude.SingleInstance", out bool first);
             if (!first) return 0;

QuickClaude.csproj

@@ -10,7 +10,7 @@
     <Nullable>disable</Nullable>
     <AssemblyName>QuickClaude</AssemblyName>
     <RootNamespace>QuickClaude</RootNamespace>
-    <Version>1.3.0</Version>
+    <Version>1.4.0</Version>
     <Product>QuickClaude</Product>
     <ApplicationIcon>app.ico</ApplicationIcon>
     <RuntimeIdentifier>win-x64</RuntimeIdentifier>

WriteGuard.cs

@@ -0,0 +1,81 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+
+namespace QuickClaude
+{
+    // QuickClaude.exe --guard-write: Claude Code's PreToolUse hook for Write, Edit and NotebookEdit.
+    // Keeps Claude from writing anywhere OpenRules lets things open without a confirm box that a
+    // normal (non-admin) account can write to: your Desktop and all of AppData (which holds your
+    // own Start Menu, AppData\Local\Programs and the Store app aliases). Without this, Claude in
+    // "Edit files" or "Auto" mode could drop a shortcut or program there and then open it unasked.
+    // Every other folder is left to the "Claude can" setting as before.
+    public static class WriteGuard
+    {
+        public static int Run()
+        {
+            string path = null, cwd = null;
+            try
+            {
+                using var stdin = new StreamReader(Console.OpenStandardInput(), new UTF8Encoding(false));
+                using var doc = JsonDocument.Parse(stdin.ReadToEnd());
+                var root = doc.RootElement;
+                cwd = Str(root, "cwd");
+                if (root.TryGetProperty("tool_input", out var input))
+                    path = Str(input, "file_path") ?? Str(input, "notebook_path") ?? Str(input, "path");
+            }
+            catch { }
+
+            if (string.IsNullOrEmpty(path)) return 0;   // nothing to check: normal rules decide
+
+            if (!Blocked(path, cwd)) return 0;
+
+            var json = JsonSerializer.Serialize(new
+            {
+                hookSpecificOutput = new
+                {
+                    hookEventName = "PreToolUse",
+                    permissionDecision = "deny",
+                    permissionDecisionReason =
+                        "QuickClaude doesn't let Claude write to the Desktop or AppData folders (programs and shortcuts there " +
+                        "can open without a confirm box). Tell the user, and suggest a different folder if one would do."
+                }
+            });
+            using var stdout = new StreamWriter(Console.OpenStandardOutput(), new UTF8Encoding(false));
+            stdout.Write(json);
+            return 0;
+        }
+
+        static bool Blocked(string path, string cwd)
+        {
+            try
+            {
+                var full = Path.IsPathRooted(path) || string.IsNullOrEmpty(cwd)
+                    ? Path.GetFullPath(path)
+                    : Path.GetFullPath(Path.Combine(cwd, path));
+                var home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
+                var dirs = new[]
+                {
+                    Path.Combine(home, "AppData"),
+                    Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
+                    Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+                    Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory),
+                    Environment.GetFolderPath(Environment.SpecialFolder.CommonDesktopDirectory),
+                    Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "Microsoft", "Windows", "Start Menu"),
+                }.Where(d => !string.IsNullOrEmpty(d));
+                return dirs.Any(d =>
+                {
+                    var root = Path.GetFullPath(d).TrimEnd('\\');
+                    return full.Equals(root, StringComparison.OrdinalIgnoreCase) ||
+                           full.StartsWith(root + "\\", StringComparison.OrdinalIgnoreCase);
+                });
+            }
+            catch { return true; }   // a path we can't even parse doesn't get written
+        }
+
+        static string Str(JsonElement e, string name) =>
+            e.ValueKind == JsonValueKind.Object && e.TryGetProperty(name, out var v) && v.ValueKind == JsonValueKind.String ? v.GetString() : null;
+    }
+}