#!/usr/bin/env python3
from __future__ import annotations
import logging
from base64 import b64encode
from datetime import datetime
from hashlib import md5, sha1, sha256, sha512
from io import BytesIO
from pathlib import Path
from typing import Any
from . import FileObject
from .abstractgenerator import AbstractMISPObjectGenerator
from ..exceptions import InvalidMISPObject
import lief
import lief.PE
try:
import pydeep # type: ignore
HAS_PYDEEP = True
except ImportError:
HAS_PYDEEP = False
logger = logging.getLogger('pymisp')
def make_pe_objects(lief_parsed: lief.PE.Binary,
misp_file: FileObject,
standalone: bool = True,
default_attributes_parameters: dict[str, Any] = {}) -> tuple[FileObject, PEObject, list[PESectionObject]]:
pe_object = PEObject(parsed=lief_parsed, standalone=standalone, default_attributes_parameters=default_attributes_parameters)
misp_file.add_reference(pe_object.uuid, 'includes', 'PE indicators')
pe_sections = []
for s in pe_object.sections:
pe_sections.append(s)
return misp_file, pe_object, pe_sections
[docs]
class PEObject(AbstractMISPObjectGenerator):
__pe: lief.PE.Binary
def __init__(self, parsed: lief.PE.Binary | None = None, # type: ignore[no-untyped-def]
filepath: Path | str | None = None,
pseudofile: BytesIO | list[int] | None = None,
**kwargs) -> None:
"""Creates an PE object, with lief"""
super().__init__('pe', **kwargs)
if not HAS_PYDEEP:
logger.warning("pydeep is missing, please install pymisp this way: pip install pymisp[fileobjects]")
if pseudofile:
if isinstance(pseudofile, BytesIO):
p = lief.PE.parse(obj=pseudofile)
elif isinstance(pseudofile, bytes):
p = lief.PE.parse(raw=list(pseudofile))
elif isinstance(pseudofile, list):
p = lief.PE.parse(raw=pseudofile)
else:
raise InvalidMISPObject(f'Pseudo file can be BytesIO or bytes got {type(pseudofile)}')
if not p:
raise InvalidMISPObject('Unable to parse pseudofile')
self.__pe = p
elif filepath:
if p := lief.PE.parse(filepath):
self.__pe = p
else:
raise InvalidMISPObject(f'Unable to parse {filepath}')
elif parsed:
# Got an already parsed blob
if isinstance(parsed, lief.PE.Binary):
self.__pe = parsed
else:
raise InvalidMISPObject(f'Not a lief.PE.Binary: {type(parsed)}')
self.generate_attributes()
def _is_exe(self) -> bool:
if not self._is_dll() and not self._is_driver():
return self.__pe.header.has_characteristic(lief.PE.Header.CHARACTERISTICS.EXECUTABLE_IMAGE)
return False
def _is_dll(self) -> bool:
return self.__pe.header.has_characteristic(lief.PE.Header.CHARACTERISTICS.DLL)
def _is_driver(self) -> bool:
# List from pefile
system_DLLs = {'ntoskrnl.exe', 'hal.dll', 'ndis.sys', 'bootvid.dll', 'kdcom.dll'}
if system_DLLs.intersection([imp.lower() for imp in self.__pe.libraries]):
return True
return False
def _get_pe_type(self) -> str:
if self._is_dll():
return 'dll'
elif self._is_driver():
return 'driver'
elif self._is_exe():
return 'exe'
else:
return 'unknown'
[docs]
def generate_attributes(self) -> None:
self.add_attribute('type', value=self._get_pe_type())
# General information
self.add_attribute('entrypoint-address', value=self.__pe.entrypoint)
self.add_attribute('compilation-timestamp', value=datetime.utcfromtimestamp(self.__pe.header.time_date_stamps).isoformat())
self.add_attribute('imphash', value=lief.PE.get_imphash(self.__pe, lief.PE.IMPHASH_MODE.PEFILE))
self.add_attribute('authentihash', value=self.__pe.authentihash_sha256.hex())
r_manager = self.__pe.resources_manager
if isinstance(r_manager, lief.PE.ResourcesManager):
version = r_manager.version
if isinstance(version, lief.PE.ResourceVersion) and version.string_file_info is not None:
fileinfo = dict(version.string_file_info.langcode_items[0].items.items())
self.add_attribute('original-filename', value=fileinfo.get('OriginalFilename'))
self.add_attribute('internal-filename', value=fileinfo.get('InternalName'))
self.add_attribute('file-description', value=fileinfo.get('FileDescription'))
self.add_attribute('file-version', value=fileinfo.get('FileVersion'))
self.add_attribute('product-name', value=fileinfo.get('ProductName'))
self.add_attribute('product-version', value=fileinfo.get('ProductVersion'))
self.add_attribute('company-name', value=fileinfo.get('CompanyName'))
self.add_attribute('legal-copyright', value=fileinfo.get('LegalCopyright'))
self.add_attribute('lang-id', value=version.string_file_info.langcode_items[0].key)
# Sections
self.sections = []
if self.__pe.sections:
pos = 0
for section in self.__pe.sections:
if not section.name and not section.size:
# Skip section if name is none AND size is 0.
continue
s = PESectionObject(section, standalone=self._standalone, default_attributes_parameters=self._default_attributes_parameters)
self.add_reference(s.uuid, 'includes', f'Section {pos} of PE')
if ((self.__pe.entrypoint >= section.virtual_address)
and (self.__pe.entrypoint < (section.virtual_address + section.virtual_size))):
if isinstance(section.name, bytes):
section_name = section.name.decode()
else:
section_name = section.name
self.add_attribute('entrypoint-section-at-position', value=f'{section_name}|{pos}')
pos += 1
self.sections.append(s)
self.add_attribute('number-sections', value=len(self.sections))
# Signatures
self.certificates = []
self.signers = []
for sign in self.__pe.signatures:
for c in sign.certificates:
cert_obj = PECertificate(c)
self.add_reference(cert_obj.uuid, 'signed-by')
self.certificates.append(cert_obj)
for s_info in sign.signers:
signer_obj = PESigners(s_info)
self.add_reference(signer_obj.uuid, 'signed-by')
self.signers.append(signer_obj)
class PECertificate(AbstractMISPObjectGenerator):
def __init__(self, certificate: lief.PE.x509, **kwargs) -> None: # type: ignore[no-untyped-def]
super().__init__('x509')
self.__certificate = certificate
self.generate_attributes()
def generate_attributes(self) -> None:
self.add_attribute('issuer', value=self.__certificate.issuer)
self.add_attribute('serial-number', value=self.__certificate.serial_number)
if len(self.__certificate.valid_from) == 6:
self.add_attribute('validity-not-before',
value=datetime(year=self.__certificate.valid_from[0],
month=self.__certificate.valid_from[1],
day=self.__certificate.valid_from[2],
hour=self.__certificate.valid_from[3],
minute=self.__certificate.valid_from[4],
second=self.__certificate.valid_from[5]))
if len(self.__certificate.valid_to) == 6:
self.add_attribute('validity-not-after',
value=datetime(year=self.__certificate.valid_to[0],
month=self.__certificate.valid_to[1],
day=self.__certificate.valid_to[2],
hour=self.__certificate.valid_to[3],
minute=self.__certificate.valid_to[4],
second=self.__certificate.valid_to[5]))
self.add_attribute('version', value=self.__certificate.version)
self.add_attribute('subject', value=self.__certificate.subject)
self.add_attribute('signature_algorithm', value=self.__certificate.signature_algorithm)
self.add_attribute('raw-base64', value=b64encode(self.__certificate.raw))
class PESigners(AbstractMISPObjectGenerator):
def __init__(self, signer: lief.PE.SignerInfo, **kwargs) -> None: # type: ignore[no-untyped-def]
super().__init__('authenticode-signerinfo')
self.__signer = signer
self.generate_attributes()
def generate_attributes(self) -> None:
self.add_attribute('issuer', value=self.__signer.issuer)
self.add_attribute('serial-number', value=self.__signer.serial_number)
self.add_attribute('version', value=self.__signer.version)
self.add_attribute('digest_algorithm', value=str(self.__signer.digest_algorithm))
self.add_attribute('encryption_algorithm', value=str(self.__signer.encryption_algorithm))
self.add_attribute('digest-base64', value=b64encode(self.__signer.encrypted_digest))
info: lief.PE.SpcSpOpusInfo = self.__signer.get_attribute(lief.PE.Attribute.TYPE.SPC_SP_OPUS_INFO) # type: ignore[assignment]
if info:
self.add_attribute('program-name', value=info.program_name)
self.add_attribute('url', value=info.more_info)
[docs]
class PESectionObject(AbstractMISPObjectGenerator):
def __init__(self, section: lief.PE.Section, **kwargs) -> None: # type: ignore[no-untyped-def]
"""Creates an PE Section object. Object generated by PEObject."""
super().__init__('pe-section')
self.__section = section
self.__data = bytes(self.__section.content)
self.generate_attributes()
[docs]
def generate_attributes(self) -> None:
self.add_attribute('name', value=self.__section.name)
self.add_attribute('size-in-bytes', value=self.__section.size)
if int(self.__section.size) > 0:
# zero-filled sections can create too many correlations
to_ids = float(self.__section.entropy) > 0
disable_correlation = not to_ids
self.add_attribute('entropy', value=self.__section.entropy)
self.add_attribute('md5', value=md5(self.__data).hexdigest(), disable_correlation=disable_correlation, to_ids=to_ids)
self.add_attribute('sha1', value=sha1(self.__data).hexdigest(), disable_correlation=disable_correlation, to_ids=to_ids)
self.add_attribute('sha256', value=sha256(self.__data).hexdigest(), disable_correlation=disable_correlation, to_ids=to_ids)
self.add_attribute('sha512', value=sha512(self.__data).hexdigest(), disable_correlation=disable_correlation, to_ids=to_ids)
if HAS_PYDEEP and float(self.__section.entropy) > 0:
if self.__section.name == '.rsrc':
# ssdeep of .rsrc creates too many correlations
disable_correlation = True
to_ids = False
self.add_attribute('ssdeep', value=pydeep.hash_buf(self.__data).decode(), disable_correlation=disable_correlation, to_ids=to_ids)