DLL Universal Patcher – A Comprehensive Guide To Advanced Binary Patching

DLL Universal Patcher is a flexible and convenient code patcher that doesn’t touch the files on disk.

It can be used for replacing any tasks that you’d otherwise achieve with on-disk patching, such as fixing old software on modern machines, or fixing bugs in others’ software.

In addition, due to more control over when the patching happens, it is possible to patch packed executables.

How To Use

1. Pick a suitable dll to proxy, like version.dll
2. Use dll-proxy-generator.exe --import-dll "dll_universal_patcher.dll" --import "dummy" "C:\Windows\System32\version.dll" to generate a suitable proxy dll
3. Write up your patches into patches.json (more on this later)
4. Place the generated dll, dll_universal_patcher.dll, and patches.json in target directory to perform dll hijacking

How To Use (Advanced)

1. Pick a suitable dll to proxy, like version.dll
2. Use dll-proxy-generator.exe --import-dll "dll_universal_patcher.dll" --import "dummy" "C:\Windows\System32\version.dll" to generate a suitable proxy dll
3. Write up your patches into patches.json (more on this later)
4. Use a tool like CFF Explorer to add the config as a RCDATA resource with ID 1 and neutral language to dll_universal_patcher.dll
5. Place the generated dll and dll_universal_patcher.dll in target directory to perform dll hijacking

patches.json

Example:

[
    {
        "modules": [ "winver.exe", "{exe}" ],
        "pattern": "01 02 03 04 05 ? 06 ?? 07",
        "replacement": "90 90 90 90 C3",
        "min_matches": 1,
        "max_matches": 3,
        "on_initialize": false,
        "on_process_initialized": true,
        "on_before_dllmain": false,
        "is_code": true,
        "allowed_to_fail": false,
        "multishot": false
    }
]

For more info on the options, check out the schema