Add winpeas privilege escalation checks from: The Windows Registry Adventure, Part 8: Exploitation of Hive-based Memory Corrup

winPEAS/winPEASexe/README.md

@@ -76,6 +76,7 @@ The goal of this project is to search for possible **Privilege Escalation Paths*
 
 New in this version:
 - Detect potential GPO abuse by flagging writable SYSVOL paths for GPOs applied to the current host and by highlighting membership in the "Group Policy Creator Owners" group.
+- Highlight HKLM/HKU registry keys that grant write access to low-privileged groups (including the cross-user TypingInsights key) so you can spot the hive corruption primitives documented by Project Zero.
 
 
 It should take only a **few seconds** to execute almost all the checks and **some seconds/minutes during the lasts checks searching for known filenames** that could contain passwords (the time depened on the number of files in your home folder). By default only **some** filenames that could contain credentials are searched, you can use the **searchall** parameter to search all the list (this could will add some minutes).

winPEAS/winPEASexe/winPEAS/Checks/Checks.cs

@@ -93,6 +93,7 @@ namespace winPEAS.Checks
                 new SystemCheck("activedirectoryinfo", new ActiveDirectoryInfo()),
                 new SystemCheck("cloudinfo", new CloudInfo()),
                 new SystemCheck("windowscreds", new WindowsCreds()),
+                new SystemCheck("registryinfo", new RegistryInfo()),
                 new SystemCheck("browserinfo", new BrowserInfo()),
                 new SystemCheck("filesinfo", new FilesInfo()),
                 new SystemCheck("fileanalysis", new FileAnalysis()),

winPEAS/winPEASexe/winPEAS/Checks/RegistryInfo.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using winPEAS.Helpers;
+using winPEAS.Helpers.Registry;
+
+namespace winPEAS.Checks
+{
+    internal class RegistryInfo : ISystemCheck
+    {
+        private const string TypingInsightsRelativePath = @"Software\Microsoft\Input\TypingInsights";
+
+        private static readonly string[] KnownWritableSystemKeyCandidates = new[]
+        {
+            @"SOFTWARE\Microsoft\CoreShell",
+            @"SOFTWARE\Microsoft\DRM",
+            @"SOFTWARE\Microsoft\Input\Locales",
+            @"SOFTWARE\Microsoft\Input\Settings",
+            @"SOFTWARE\Microsoft\Shell\Oobe",
+            @"SOFTWARE\Microsoft\Shell\Session",
+            @"SOFTWARE\Microsoft\Tracing",
+            @"SOFTWARE\Microsoft\Windows\UpdateApi",
+            @"SOFTWARE\Microsoft\WindowsUpdate\UX",
+            @"SOFTWARE\WOW6432Node\Microsoft\DRM",
+            @"SOFTWARE\WOW6432Node\Microsoft\Tracing",
+            @"SYSTEM\Software\Microsoft\TIP",
+            @"SYSTEM\ControlSet001\Control\Cryptography\WebSignIn\Navigation",
+            @"SYSTEM\ControlSet001\Control\MUI\StringCacheSettings",
+            @"SYSTEM\ControlSet001\Control\USB\AutomaticSurpriseRemoval",
+            @"SYSTEM\ControlSet001\Services\BTAGService\Parameters\Settings",
+        };
+
+        private static readonly string[] ScanBasePaths = new[]
+        {
+            @"SOFTWARE\Microsoft",
+            @"SOFTWARE\WOW6432Node\Microsoft",
+            @"SYSTEM\CurrentControlSet\Services",
+            @"SYSTEM\CurrentControlSet\Control",
+            @"SYSTEM\ControlSet001\Control",
+        };
+
+        public void PrintInfo(bool isDebug)
+        {
+            Beaprint.GreatPrint("Registry permissions for hive exploitation");
+
+            new List<Action>
+            {
+                PrintTypingInsightsPermissions,
+                PrintKnownSystemWritableKeys,
+                PrintHeuristicWritableKeys,
+            }.ForEach(action => CheckRunner.Run(action, isDebug));
+        }
+
+        private void PrintTypingInsightsPermissions()
+        {
+            Beaprint.MainPrint("Cross-user TypingInsights key (HKCU/HKU)");
+
+            var matches = new List<RegistryWritableKeyInfo>();
+            var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+            if (RegistryAclScanner.TryGetWritableKey("HKCU", TypingInsightsRelativePath, out var currentUserKey))
+            {
+                if (seen.Add(currentUserKey.FullPath))
+                {
+                    matches.Add(currentUserKey);
+                }
+            }
+
+            foreach (var sid in RegistryHelper.GetUserSIDs())
+            {
+                if (string.IsNullOrEmpty(sid) || sid.Equals(".DEFAULT", StringComparison.OrdinalIgnoreCase) || sid.EndsWith("_Classes", StringComparison.OrdinalIgnoreCase))
+                {
+                    continue;
+                }
+
+                string relativePath = $"{sid}\\{TypingInsightsRelativePath}";
+                if (RegistryAclScanner.TryGetWritableKey("HKU", relativePath, out var info) && seen.Add(info.FullPath))
+                {
+                    matches.Add(info);
+                }
+            }
+
+            if (matches.Count == 0)
+            {
+                Beaprint.GrayPrint("  [-] TypingInsights key does not grant write access to low-privileged groups.");
+                return;
+            }
+
+            PrintEntries(matches);
+            Beaprint.LinkPrint("https://projectzero.google/2025/05/the-windows-registry-adventure-8-exploitation.html", "Writable TypingInsights enables cross-user hive tampering and DoS.");
+        }
+
+        private void PrintKnownSystemWritableKeys()
+        {
+            Beaprint.MainPrint("Known HKLM descendants writable by standard users");
+
+            var matches = new List<RegistryWritableKeyInfo>();
+            foreach (var path in KnownWritableSystemKeyCandidates)
+            {
+                if (RegistryAclScanner.TryGetWritableKey("HKLM", path, out var info))
+                {
+                    matches.Add(info);
+                }
+            }
+
+            if (matches.Count == 0)
+            {
+                Beaprint.GrayPrint("  [-] None of the tracked HKLM keys are writable by low-privileged groups.");
+                return;
+            }
+
+            PrintEntries(matches);
+        }
+
+        private void PrintHeuristicWritableKeys()
+        {
+            Beaprint.MainPrint("Sample of additional writable HKLM keys (depth-limited scan)");
+
+            var matches = RegistryAclScanner.ScanWritableKeys("HKLM", ScanBasePaths, maxDepth: 3, maxResults: 25);
+            if (matches.Count == 0)
+            {
+                Beaprint.GrayPrint("  [-] No additional writable HKLM keys were found within the sampled paths.");
+                return;
+            }
+
+            PrintEntries(matches);
+            Beaprint.GrayPrint("  [*] Showing up to 25 entries from the sampled paths to avoid noisy output.");
+        }
+
+        private static void PrintEntries(IEnumerable<RegistryWritableKeyInfo> entries)
+        {
+            foreach (var entry in entries)
+            {
+                var principals = string.Join(", ", entry.Principals);
+                var rights = entry.Rights.Count > 0 ? string.Join(", ", entry.Rights.Distinct(StringComparer.OrdinalIgnoreCase)) : "Write access";
+                var displayPath = string.IsNullOrEmpty(entry.FullPath) ? $"{entry.Hive}\\{entry.RelativePath}" : entry.FullPath;
+                Beaprint.BadPrint($"  [!] {displayPath} -> {principals} ({rights})");
+            }
+        }
+    }
+}

winPEAS/winPEASexe/winPEAS/Helpers/Beaprint.cs

@@ -132,6 +132,7 @@ namespace winPEAS.Helpers
             Console.WriteLine(LCYAN + "        activedirectoryinfo" + GRAY + "   Quick AD checks (gMSA readable passwords, AD CS template rights)" + NOCOLOR);
             Console.WriteLine(LCYAN + "        cloudinfo" + GRAY + "            Enumerate cloud information" + NOCOLOR);
             Console.WriteLine(LCYAN + "        windowscreds" + GRAY + "         Search windows credentials" + NOCOLOR);
+            Console.WriteLine(LCYAN + "        registryinfo" + GRAY + "         Flag writable HKLM/HKU keys that enable hive tampering" + NOCOLOR);
             Console.WriteLine(LCYAN + "        browserinfo" + GRAY + "          Search browser information" + NOCOLOR);
             Console.WriteLine(LCYAN + "        filesinfo" + GRAY + "            Search generic files that can contains credentials" + NOCOLOR);
             Console.WriteLine(LCYAN + "        fileanalysis" + GRAY + "         [NOT RUN BY DEFAULT] Search specific files that can contains credentials and for regexes inside files. Might take several minutes." + NOCOLOR);

winPEAS/winPEASexe/winPEAS/Helpers/Registry/RegistryAclScanner.cs

@@ -0,0 +1,221 @@
+using Microsoft.Win32;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.AccessControl;
+using System.Security.Principal;
+using winPEAS.Helpers;
+
+namespace winPEAS.Helpers.Registry
+{
+    internal class RegistryWritableKeyInfo
+    {
+        public string Hive { get; set; }
+        public string RelativePath { get; set; }
+        public string FullPath { get; set; }
+        public List<string> Principals { get; set; } = new List<string>();
+        public List<string> Rights { get; set; } = new List<string>();
+    }
+
+    internal static class RegistryAclScanner
+    {
+        private static readonly Dictionary<string, string> LowPrivSidMap = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
+        {
+            { new SecurityIdentifier(WellKnownSidType.BuiltinUsersSid, null).Value, "BUILTIN\\Users" },
+            { new SecurityIdentifier(WellKnownSidType.AuthenticatedUserSid, null).Value, "Authenticated Users" },
+            { new SecurityIdentifier(WellKnownSidType.WorldSid, null).Value, "Everyone" },
+            { new SecurityIdentifier(WellKnownSidType.InteractiveSid, null).Value, "Interactive" },
+            { new SecurityIdentifier(WellKnownSidType.BuiltinGuestsSid, null).Value, "BUILTIN\\Guests" },
+        };
+
+        public static bool TryGetWritableKey(string hive, string relativePath, out RegistryWritableKeyInfo info)
+        {
+            info = null;
+            using (var key = OpenKey(hive, relativePath))
+            {
+                if (key == null)
+                {
+                    return false;
+                }
+
+                return TryCollectWritableInfo(hive, relativePath, key, out info);
+            }
+        }
+
+        public static List<RegistryWritableKeyInfo> ScanWritableKeys(string hive, IEnumerable<string> basePaths, int maxDepth, int maxResults)
+        {
+            var results = new List<RegistryWritableKeyInfo>();
+            var seenPaths = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+            foreach (var basePath in basePaths ?? Enumerable.Empty<string>())
+            {
+                if (results.Count >= maxResults)
+                {
+                    break;
+                }
+
+                using (var key = OpenKey(hive, basePath))
+                {
+                    if (key == null)
+                    {
+                        continue;
+                    }
+
+                    Traverse(hive, key, basePath, 0, maxDepth, maxResults, seenPaths, results);
+                }
+            }
+
+            return results;
+        }
+
+        private static void Traverse(string hive, RegistryKey currentKey, string currentPath, int depth, int maxDepth, int maxResults, HashSet<string> seenPaths, List<RegistryWritableKeyInfo> results)
+        {
+            if (currentKey == null || results.Count >= maxResults)
+            {
+                return;
+            }
+
+            if (TryCollectWritableInfo(hive, currentPath, currentKey, out var info))
+            {
+                if (seenPaths.Add(info.FullPath))
+                {
+                    results.Add(info);
+                }
+
+                if (results.Count >= maxResults)
+                {
+                    return;
+                }
+            }
+
+            if (depth >= maxDepth)
+            {
+                return;
+            }
+
+            string[] subKeys;
+            try
+            {
+                subKeys = currentKey.GetSubKeyNames();
+            }
+            catch
+            {
+                return;
+            }
+
+            foreach (var subKeyName in subKeys)
+            {
+                if (results.Count >= maxResults)
+                {
+                    break;
+                }
+
+                try
+                {
+                    using (var childKey = currentKey.OpenSubKey(subKeyName))
+                    {
+                        if (childKey == null)
+                        {
+                            continue;
+                        }
+
+                        string childPath = string.IsNullOrEmpty(currentPath) ? subKeyName : $"{currentPath}\\{subKeyName}";
+                        Traverse(hive, childKey, childPath, depth + 1, maxDepth, maxResults, seenPaths, results);
+                    }
+                }
+                catch
+                {
+                    // Ignore keys we cannot open
+                }
+            }
+        }
+
+        private static bool TryCollectWritableInfo(string hive, string relativePath, RegistryKey key, out RegistryWritableKeyInfo info)
+        {
+            info = null;
+
+            try
+            {
+                var acl = key.GetAccessControl(AccessControlSections.Access);
+
+                var principals = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+                var rights = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                foreach (RegistryAccessRule rule in acl.GetAccessRules(true, true, typeof(SecurityIdentifier)))
+                {
+                    if (rule.AccessControlType != AccessControlType.Allow)
+                    {
+                        continue;
+                    }
+
+                    var sid = rule.IdentityReference as SecurityIdentifier ?? rule.IdentityReference.Translate(typeof(SecurityIdentifier)) as SecurityIdentifier;
+                    if (sid == null)
+                    {
+                        continue;
+                    }
+
+                    if (!LowPrivSidMap.TryGetValue(sid.Value, out var label))
+                    {
+                        continue;
+                    }
+
+                    string interestingRight = PermissionsHelper.PermInt2Str((int)rule.RegistryRights, PermissionType.WRITEABLE_OR_EQUIVALENT_REG);
+                    if (string.IsNullOrEmpty(interestingRight))
+                    {
+                        continue;
+                    }
+
+                    principals.Add($"{label} ({sid.Value})");
+                    rights.Add(interestingRight);
+                }
+
+                if (principals.Count == 0)
+                {
+                    return false;
+                }
+
+                string normalizedRelativePath = relativePath ?? string.Empty;
+                string fullPath = string.IsNullOrEmpty(normalizedRelativePath) ? key.Name : $"{hive}\\{normalizedRelativePath}";
+
+                info = new RegistryWritableKeyInfo
+                {
+                    Hive = hive,
+                    RelativePath = normalizedRelativePath,
+                    FullPath = fullPath,
+                    Principals = principals.ToList(),
+                    Rights = rights.ToList(),
+                };
+                return true;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        private static RegistryKey OpenKey(string hive, string path)
+        {
+            if (string.IsNullOrEmpty(path))
+            {
+                return null;
+            }
+
+            try
+            {
+                RegistryKey baseKey = hive switch
+                {
+                    "HKLM" => Registry.LocalMachine,
+                    "HKCU" => Registry.CurrentUser,
+                    "HKU" => Registry.Users,
+                    _ => null,
+                };
+
+                return baseKey?.OpenSubKey(path);
+            }
+            catch
+            {
+                return null;
+            }
+        }
+    }
+}

winPEAS/winPEASexe/winPEAS/winPEAS.csproj

@@ -1200,6 +1200,7 @@
     <Compile Include="Checks\SystemInfo.cs" />
     <Compile Include="Checks\UserInfo.cs" />
     <Compile Include="Checks\WindowsCreds.cs" />
+    <Compile Include="Checks\RegistryInfo.cs" />
     <Compile Include="Helpers\AppLocker\AppLockerHelper.cs" />
     <Compile Include="Helpers\AppLocker\AppLockerRules.cs" />
     <Compile Include="Helpers\AppLocker\IAppIdPolicyHandler.cs" />
@@ -1464,6 +1465,7 @@
     <Compile Include="Helpers\CheckRunner.cs" />
     <Compile Include="Helpers\ReflectionHelper.cs" />
     <Compile Include="Helpers\Registry\RegistryHelper.cs" />
+    <Compile Include="Helpers\Registry\RegistryAclScanner.cs" />
     <Compile Include="Helpers\Search\SearchHelper.cs" />
     <Compile Include="Wifi\Wifi.cs" />
     <Compile Include="Wifi\NativeWifiApi\Interop.cs" />