- Added .NET Core 3.1 support

src/apphost-extract/apphost-extract-v2/Analyzer.cs

@@ -1,5 +1,8 @@
-using System;
+using apphost_extract_v2.General;
+using apphost_extract_v2.Models;
+using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Reflection.PortableExecutable;
@@ -12,8 +15,8 @@ namespace apphost_extract_v2
         private FileStream File;
         public PEHeaders PEHeader;
 
-        private readonly byte[] VERSION_SIGNATURE = new byte[] { };
+        private readonly byte[] VERSION_SIGNATURE = new byte[] { 0x4C, 0x8D, 0x05, 0x0, 0x0, 0x0, 0x0, 0x48, 0x8D, 0x15, 0x0, 0x0, 0x0, 0x0, 0x48, 0x8D, 0x0D, 0x0, 0x0, 0x0, 0x0 };
-        private const string VERSION_SIGNATURE_MASK = "";
+        private const string VERSION_SIGNATURE_MASK = "xxx???xxxx???xxxx???x";
 
         public Analyzer(FileStream fs)
         {
@@ -21,23 +24,77 @@ namespace apphost_extract_v2
             PEHeader = new PEHeaders(fs);
         }
 
+        public IApphostFile Open()
+        {
+            var textSegment = GetSegment(".text");
+            var sw = Stopwatch.StartNew();
+            var sigscanResults = Util.PatternScan(File, 
+                                textSegment.PointerToRawData, textSegment.SizeOfRawData,
+                                    VERSION_SIGNATURE, VERSION_SIGNATURE_MASK);
+            sw.Stop();
+            Log.Info($"Scan took {sw.ElapsedMilliseconds}ms | Version String Instructions -> {sigscanResults[0]:X8}");
+            if (sigscanResults.Length == 0)
+                return null;
+           
+            var versionOffset = (int)BitConverter.ToUInt32(File.ReadBuffer(sigscanResults[0] + 3, 4));
+            var versionStringPtr = AddVirtualOffset(sigscanResults[0] + 7, versionOffset);
+            var versionString = Encoding.Unicode.GetString(
+                                                File.ReadBuffer(
+                                                    versionStringPtr, 6));
+
+            Log.Info($"Translated virtual offset -> {versionStringPtr:X8}: {versionString}");
+
+            switch (versionString)
+            {
+                case "3.0":
+                    return new ApphostFile30(File, PEHeader);
+                    
+                case "3.1":
+                    return new ApphostFile31(File, PEHeader);
+
+                case "5.0":
+                    return new ApphostFile5(File, PEHeader);
+                default:
+                    return null;
+            }
+        }
+
+        private int AddVirtualOffset(int fileAddress, int offset)
+        {
+            return VirtualAddressToFileOffset(FileOffsetToVirtualAddress(fileAddress) + offset);
+        }
+
+        private int FileOffsetToVirtualAddress(int offset)
+        {
+            var section = FindSection(offset, true);
+            return offset + (section.VirtualAddress - section.PointerToRawData);
+        }
+
+        private int VirtualAddressToFileOffset(int address)
+        {
+            var section = FindSection(address, false);
+            return address - (section.VirtualAddress - section.PointerToRawData);
+        }
+
         public SectionHeader GetSegment(string name)
         {
             var section = PEHeader.SectionHeaders.Where(x => x.Name == name).FirstOrDefault();
             return section;
         }
 
-        public ApphostVersion GetVersion()
+        public SectionHeader FindSection(int address, bool fileOffset)
         {
+            foreach (var section in PEHeader.SectionHeaders)
+            {
+                if (fileOffset)
+                {
+                    if (section.PointerToRawData < address && section.PointerToRawData + section.SizeOfRawData > address) return section;
+                }
+                else
+                    if (section.VirtualAddress < address && section.VirtualAddress + section.VirtualSize > address) return section;
+            }
 
+            return new SectionHeader();
         }
-
-    }
-
-    public enum ApphostVersion
-    {
-        NET30,
-        NET31,
-        NET5
     }
 }

src/apphost-extract/apphost-extract-v2/Models/ApphostFile30.cs

@@ -0,0 +1,21 @@
+using apphost_extract_v2.General;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection.PortableExecutable;
+using System.Text;
+
+namespace apphost_extract_v2.Models
+{
+    public class ApphostFile30 : IApphostFile
+    {
+        public ApphostFile30(FileStream fs, PEHeaders peheader) : base(fs, peheader) { }
+
+        public override void Close()
+        {
+            throw new NotImplementedException();
+        }
+
+     
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/ApphostFile31.cs

@@ -0,0 +1,69 @@
+using apphost_extract_v2.General;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection.PortableExecutable;
+using System.Text;
+
+namespace apphost_extract_v2.Models
+{
+    public class ApphostFile31 : IApphostFile
+    {
+        private const int HEADER_OFFSET_PTR = 0x27600;
+        private const int HEADER_SIZE = 0xD;
+        private const int FILE_ENTRY_SIZE = 0x12;
+
+        public ApphostFile31(FileStream fs, PEHeaders peheader) : base(fs, peheader)
+        {
+            Header = new AppHostFileHeader();
+            var headerAddress = BitConverter.ToInt32(fs.ReadBuffer(HEADER_OFFSET_PTR, 4));
+            var headerBuffer = fs.ReadBuffer(headerAddress, HEADER_SIZE);
+
+            Header.Raw = headerBuffer;
+            Header.Path = Encoding.UTF8.GetString(fs.ReadBuffer(headerAddress + HEADER_SIZE, 0xC));
+            
+            Header.Manifest = ParseManifest();
+            
+        }
+
+        private AppHostManifest ParseManifest()
+        {
+            AppHostManifest manifest = new AppHostManifest();
+            var embeddedFileCount = BitConverter.ToInt32(Header.Raw, 0x8);
+
+            for(int i = 0; i< embeddedFileCount; i++)
+            {
+                manifest.FileEntries.Add(GetNextEntry());
+            }
+
+            return manifest;
+        }
+
+        private AppHostFileEntry GetNextEntry()
+        {
+            AppHostFileEntry entry = new AppHostFileEntry();
+            byte[] entryBuffer = new byte[FILE_ENTRY_SIZE];
+            FileStream.Read(entryBuffer, 0, entryBuffer.Length);
+            entry.Raw = entryBuffer;
+
+            entry.Offset = BitConverter.ToInt64(entry.Raw, 0);
+
+            //hopefully nobody embeds a file larger than 2GB :D
+            entry.Size = (int)BitConverter.ToInt64(entry.Raw, 0x8);
+
+            byte[] stringBuffer = new byte[entry.Raw[0x11]];
+            FileStream.Read(stringBuffer, 0, stringBuffer.Length);
+            entry.Name = Encoding.UTF8.GetString(stringBuffer);
+
+            return entry;
+        }
+
+
+
+        public override void Close()
+        {
+            FileStream.Close();
+        }
+
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/ApphostFile5.cs

@@ -0,0 +1,20 @@
+using apphost_extract_v2.General;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection.PortableExecutable;
+using System.Text;
+
+namespace apphost_extract_v2.Models
+{
+    public class ApphostFile5 : IApphostFile
+    {
+        public ApphostFile5(FileStream fs, PEHeaders peheader) : base(fs, peheader) { }
+
+        public override void Close()
+        {
+            throw new NotImplementedException();
+        }
+
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/General/AppHostFileEntry.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace apphost_extract_v2.General
+{
+    public class AppHostFileEntry
+    {
+        public long Offset { get; set; }
+        public int Size { get; set; }
+        public string Name { get; set; }
+
+        public byte[] Raw;
+      
+
+        //public AppHostFileEntry()
+        //{
+        //    FileStream = File;
+        //    byte[] entryBuffer = new byte[FILE_ENTRY_SIZE];
+        //    File.Read(entryBuffer, 0, entryBuffer.Length);
+        //    Raw = entryBuffer;
+
+        //    Offset = BitConverter.ToInt64(Raw, 0);
+
+        //    //hopefully nobody embeds a file larger than 2GB :D
+        //    Size = (int)BitConverter.ToInt64(Raw, 0x8); 
+
+        //    byte[] stringBuffer = new byte[Raw[0x11]];
+        //    File.Read(stringBuffer, 0, stringBuffer.Length);
+        //    Name = Encoding.UTF8.GetString(stringBuffer);
+        //}
+
+        //public byte[] Read()
+        //{
+        //    //jumps to the offsets and reads the bytes
+        //    byte[] buffer = new byte[Size];
+        //    FileStream.Seek(Offset, SeekOrigin.Begin);
+        //    FileStream.Read(buffer, 0, Size);
+        //    return buffer;
+        //}
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/General/AppHostFileHeader.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace apphost_extract_v2.General
+{
+    public class AppHostFileHeader
+    {
+        public byte[] Raw;
+
+        public string Path { get; set; }
+        
+        public AppHostManifest Manifest { get; set; }
+
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/General/AppHostManifest.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace apphost_extract_v2.General
+{
+    public class AppHostManifest
+    {
+        public List<AppHostFileEntry> FileEntries { get; set; }
+
+        public AppHostManifest()
+        {
+            FileEntries = new List<AppHostFileEntry>();
+            //List<AppHostFileEntry> entries = new List<AppHostFileEntry>();
+
+            //for (int i = 0; i < embeddedFileCount; i++)
+            //{
+            //    AppHostFileEntry entry = new AppHostFileEntry(File);
+            //    entries.Add(entry);
+            //}
+            //FileEntries = entries.AsReadOnly();
+
+            //Log.Info("Manifest parsed successfully!");
+        }
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/General/IApphostFile.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection.PortableExecutable;
+using System.Text;
+
+namespace apphost_extract_v2.General
+{
+    public abstract class IApphostFile
+    {
+        internal FileStream FileStream;
+        public PEHeaders PEHeader;
+        public AppHostFileHeader Header;
+
+        public IApphostFile(FileStream fs, PEHeaders peheader)
+        {
+            FileStream = fs;
+            PEHeader = peheader;
+        }
+
+        public void ExtractAll(string outputDir)
+        {
+            Directory.CreateDirectory(outputDir);
+            foreach (var fileEntry in Header.Manifest.FileEntries)
+            {
+                try
+                {
+                    var bytes = FileStream.ReadBuffer(fileEntry.Offset, fileEntry.Size);
+                    var name = fileEntry.Name;
+                    var filePath = Path.Combine(outputDir, name);
+                    File.WriteAllBytes(filePath, bytes);
+
+                    Log.Critical($"Extracted {name}");
+
+                }
+                catch (Exception ex)
+                {
+                    Log.Error($"Could not extract {fileEntry.Name}: {ex.Message}");
+                }
+
+            }
+        }
+
+        public abstract void Close();
+    }
+}

src/apphost-extract/apphost-extract-v2/Models/IApphostFile.cs

@@ -1,11 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace apphost_extract_v2.Models
-{
-    public interface IApphostFile
-    {
-
-    }
-}

src/apphost-extract/apphost-extract-v2/Program.cs

@@ -10,18 +10,21 @@ namespace apphost_extract_v2
     {
         static void Main(string[] args)
         {
-            var file = "net31-fd.exe";
+            var file = args[0];
             var fs = new FileStream(file, FileMode.Open, FileAccess.Read);
-
+            var anal = new Analyzer(fs);
-            var d = new Analyzer(fs).GetTextSectionVA();
+            var af = anal.Open();
-            var pattern = new byte[] { 0x4c, 0x8D, 0x5, 0xE2, 0x8A, 0x00, 0x00 };
+            var path = new FileInfo(file);
-            string mask = "xxxxxxx";
+            var directory = Path.Combine(path.DirectoryName, path.Name.Remove(path.Name.Length - path.Extension.Length) + "_extracted");
-
+            af.ExtractAll(directory);
-            Log.Info("Scanning for pattern...");
+            Console.ReadLine();
-            Stopwatch sw = Stopwatch.StartNew();
+            //RunTest("net30-sc.exe");
-            var res = Util.PatternScan(fs, 0, (int)fs.Length, pattern, mask);
+            //RunTest("net5-sc.exe");
-            sw.Stop();
+            //Log.Info("Scanning for pattern...");
-            Log.Info("Found pattern at " + res[0].ToString("X8") + $" in {sw.ElapsedMilliseconds}ms");
+            //Stopwatch sw = Stopwatch.StartNew();
+            //var res = Util.PatternScan(fs, 0, (int)fs.Length, pattern, mask);
+            //sw.Stop();
+            //Log.Info("Found pattern at " + res[0].ToString("X8") + $" in {sw.ElapsedMilliseconds}ms");
 
 
 
@@ -43,6 +46,14 @@ namespace apphost_extract_v2
              Console.ReadLine();*/
         }
 
+        //static void RunTest(string file)
+        //{
+        //    Log.Info("Running test on " + file + ", scanning for version sig...");
+            
+
+        //    var d = new Analyzer(fs).GetVersion();
+        //}
+
         static FileInfo GetPath(string[] args)
         {
             try

src/apphost-extract/apphost-extract-v2/Util.cs

@@ -9,9 +9,7 @@ namespace apphost_extract_v2
     {
         public static int[] PatternScan(FileStream fs, int start, int length, byte[] pattern, string mask)
         {
-            byte[] scanBuffer = new byte[length];
+            byte[] scanBuffer = fs.ReadBuffer(start, length);
-            fs.Seek(start, SeekOrigin.Begin);
-            fs.Read(scanBuffer, 0, length);
 
             List<int> scanResults = new List<int>();
 
@@ -39,5 +37,13 @@ namespace apphost_extract_v2
 
             return true;
         }
+
+        public static byte[] ReadBuffer(this FileStream fs, long start, int length)
+        {
+            byte[] buff = new byte[length];
+            fs.Seek(start, SeekOrigin.Begin);
+            fs.Read(buff, 0, length);
+            return buff;
+        }
     }
 }