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