Patchers

Category: Tools

Patchers are tools that modify executables by changing specific bytes or instructions. They're commonly used to bypass license checks, remove nag screens, or modify program behavior.

Types of Patches

  • Byte patches - Direct modification of machine code bytes
  • Instruction patches - Changing assembly instructions
  • Import patches - Redirecting function calls
  • Resource patches - Modifying embedded resources

Popular Patching Tools

  • HxD - Hex editor for simple byte patches
  • 010 Editor - Advanced hex editor with templates
  • x64dbg - Debugger with built-in patching
  • OllyDbg - Classic debugger for patching
  • Resource Hacker - Modify Windows resources
  • PE Explorer - PE file editor

Common Patching Techniques

Common modifications include:

  • NOP out checks - Replace conditional jumps with NOPs
  • Change return values - Modify functions to return success
  • Skip code sections - Add unconditional jumps
  • Modify strings - Change text in the executable
  • Hook functions - Redirect to custom code

Patching Process

  1. Load executable in debugger or hex editor
  2. Locate the code to modify
  3. Identify the bytes to change
  4. Apply the patch
  5. Test the modified executable
  6. Save the patched file

Note: Always backup original files before patching. Some patches may break functionality or cause crashes.