change-winver.py

#!/usr/bin/python3
"""Based on https://board.eclipse.cx/viewtopic.php?t=652 ."""

import sys

version = (5, 0)

path = sys.argv[1]
with open(path, "rb+") as f:
    # offset varies! AltBacktick vs 010keygen
    """
				PIMAGE_DOS_HEADER pDosHeader = (PIMAGE_DOS_HEADER)pBuffer;
				PIMAGE_NT_HEADERS32 pNTHeaders = (PIMAGE_NT_HEADERS)((DWORD)pBuffer + pDosHeader->e_lfanew);
"""
    
    f.seek(0x3c)
    AddressOfNewExeHeader = int.from_bytes(f.read(4), "little")
    
    addrMajorOperatingSystemVersion = AddressOfNewExeHeader + 0x40    
    f.seek(addrMajorOperatingSystemVersion)
    oldver_b = f.read(4)
    oldver = (int.from_bytes(oldver_b[0:2], "little"), int.from_bytes(oldver_b[2:4], "little"))
    print("Current version:", oldver)
    print("New version:", version)
    
    version_b = b"".join(i.to_bytes(2, "little") for i in version)
    f.seek(addrMajorOperatingSystemVersion)
    f.write(version_b)
    f.flush()