Files
2025-04-14 23:45:09 +03:00

73 lines
3.5 KiB
C#

/*
* This file is part of the Astral-PE project.
* Copyright (c) 2025 DosX. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Astral-PE is a low-level post-compilation PE header mutator (obfuscator) for native
* Windows x86/x64 binaries. It modifies structural metadata while preserving execution integrity.
*
* For source code, updates, and documentation, visit:
* https://github.com/DosX-dev/Astral-PE
*/
using PeNet;
using PeNet.Header.Pe;
namespace AstralPE.Obfuscator.Modules {
public class ExportFaker : IAstralPeModule {
/// <summary>
/// If the PE file has no export directory, this method fakes the export directory
/// by setting the export RVA to the first section's virtual address and setting a fake size.
/// </summary>
/// <param name="raw">The raw byte array of the PE file.</param>
/// <param name="pe">The parsed PE file.</param>
/// <param name="e_lfanew">Offset to IMAGE_NT_HEADERS.</param>
/// <param name="optStart">Start offset of the Optional Header.</param>
/// <param name="sectionTableOffset">Offset to the section table.</param>
/// <param name="rnd">Random number generator (not used in this method).</param>
public void Apply(ref byte[] raw, PeFile pe, int e_lfanew, int optStart, int sectionTableOffset, Random rnd) {
// Ensure section headers are present
if (pe.ImageSectionHeaders == null)
throw new InvalidPeImageException();
// If the PE file already has exports, no need to fake them
if (pe.ExportedFunctions != null)
return;
// Get the first section header to use its Virtual Address for the fake export directory
ImageSectionHeader? firstSection = pe.ImageSectionHeaders.FirstOrDefault();
if (firstSection == null)
throw new Exception("No section headers found. Cannot fake export directory.");
// Set the fake export RVA to the first section's Virtual Address
uint fakeExportRVA = firstSection.VirtualAddress;
// Calculate the offset for the export directory in the Optional Header
int exportDirOffset = optStart + 0x60 + 0 * 8;
// Write the fake export RVA and size (0x28) to the raw bytes at the export directory offset
BitConverter.GetBytes(fakeExportRVA).CopyTo(raw, exportDirOffset); // Fake RVA
BitConverter.GetBytes(0x28u).CopyTo(raw, exportDirOffset + 4); // Fake size
}
}
}