lief-iat-reconstruction/patch.py

72 lines
3.3 KiB
Python

import lief
import utils
from utils import Instructions, hex_address_to_memory_representation, is_32b, is_little_endian
def patch_direct_adress_call(pe: lief.PE.Binary, rva: int, instruction_offset: int):
# We can manually patch the instruction here: FF 15 08 10 00 01 represents `call [0x01001080]`
new_value = hex_address_to_memory_representation(
hex(rva + pe.imagebase),
is_32b(pe),
is_little_endian(pe),
)
pe.patch_address(instruction_offset, Instructions.CALL_ADDR + new_value, lief.Binary.VA_TYPES.RVA)
utils.print_debug(f" Patched a call at addr {hex(pe.imagebase + instruction_offset)}")
def patch_direct_adress_jump(pe: lief.PE.Binary, rva: int, instruction_offset: int):
# We can manually patch the instruction here: FF 15 08 10 00 01 represents `call [0x01001080]`
new_value = hex_address_to_memory_representation(hex(rva + pe.imagebase), is_32b(pe), is_little_endian(pe))
pe.patch_address(instruction_offset, Instructions.JUMP_ADDR + new_value, lief.Binary.VA_TYPES.RVA)
utils.print_debug(f" Patched a jump at addr {hex(pe.imagebase + instruction_offset)}")
def patch_instr_to_new_IAT_entry(pe: lief.PE.Binary, call: dict[str, str], rva: int):
base = pe.imagebase
instruction_offset = int(call["adress"], 16) - base
memview = pe.get_content_from_virtual_address(instruction_offset, 2)
if [memview[0], memview[1]] == Instructions.CALL_ADDR:
patch_direct_adress_call(pe, rva, instruction_offset)
elif [memview[0], memview[1]] == Instructions.JUMP_ADDR:
patch_direct_adress_jump(pe, rva, instruction_offset)
def patch_addr_found_in_mem(pe: lief.PE.Binary, rva: int, old_addr: str):
is_32 = pe.abstract.header.is_32
little_endian = pe.abstract.header.endianness == lief.Header.ENDIANNESS.LITTLE
# scan memory for reference to old addr
old_addr_mem_repr = hex_address_to_memory_representation(old_addr, is_32b(pe), is_little_endian(pe))
new_addr = hex_address_to_memory_representation(hex(rva + pe.imagebase), is_32, little_endian)
found_ref_addr = []
found_xref_addr = []
for section in pe.sections:
for i in range(len(section.content)):
found = True
for j in range(len(old_addr_mem_repr)):
if i + j >= len(section.content) or section.content[i + j] != old_addr_mem_repr[j]:
found = False
break
if found:
ref_addr = hex_address_to_memory_representation(
hex(
section.virtual_address + i + pe.imagebase,
),
is_32,
little_endian,
)
found_ref_addr.append(ref_addr)
for section in pe.sections:
for ref_addr in found_ref_addr:
for k in range(len(section.content) - len(ref_addr)):
foundxref = True
for L in range(len(ref_addr)):
if section.content[k + L] != ref_addr[L]:
foundxref = False
break
if foundxref:
found_xref_addr.append(section.virtual_address + k)
for addr in found_xref_addr:
pe.patch_address(addr, new_addr, lief.Binary.VA_TYPES.RVA)
utils.print_debug(f" Patched an xref to old IAT at {hex(pe.imagebase + addr)}")