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-#!/usr/bin/python
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-''' Extracts some basic features from PE files. Many of the features
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-implemented have been used in previously published works. For more information,
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-check out the following resources:
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-* Schultz, et al., 2001: http://128.59.14.66/sites/default/files/binaryeval-ieeesp01.pdf
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-* Kolter and Maloof, 2006: http://www.jmlr.org/papers/volume7/kolter06a/kolter06a.pdf
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-* Shafiq et al., 2009: https://www.researchgate.net/profile/Fauzan_Mirza/publication/242084613_A_Framework_for_Efficient_Mining_of_Structural_Information_to_Detect_Zero-Day_Malicious_Portable_Executables/links/0c96052e191668c3d5000000.pdf
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-* Raman, 2012: http://2012.infosecsouthwest.com/files/speaker_materials/ISSW2012_Selecting_Features_to_Classify_Malware.pdf
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-* Saxe and Berlin, 2015: https://arxiv.org/pdf/1508.03096.pdf
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-
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-It may be useful to do feature selection to reduce this set of features to a meaningful set
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-for your modeling problem.
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-'''
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-
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-import hashlib
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-import json
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-import os
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-import re
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-
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-import lief
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-import numpy as np
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-from sklearn.feature_extraction import FeatureHasher
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-
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-LIEF_MAJOR, LIEF_MINOR, _ = lief.__version__.split('.')
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-LIEF_EXPORT_OBJECT = int(LIEF_MAJOR) > 0 or (int(LIEF_MAJOR) == 0 and int(LIEF_MINOR) >= 10)
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-LIEF_HAS_SIGNATURE = int(LIEF_MAJOR) > 0 or (int(LIEF_MAJOR) == 0 and int(LIEF_MINOR) >= 11)
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-
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-
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-class FeatureType(object):
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- ''' Base class from which each feature type may inherit '''
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-
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- name = ''
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- dim = 0
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-
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- def __repr__(self):
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- return '{}({})'.format(self.name, self.dim)
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-
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- def raw_features(self, bytez, lief_binary):
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- ''' Generate a JSON-able representation of the file '''
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- raise (NotImplementedError)
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-
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- def process_raw_features(self, raw_obj):
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- ''' Generate a feature vector from the raw features '''
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- raise (NotImplementedError)
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-
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- def feature_vector(self, bytez, lief_binary):
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- ''' Directly calculate the feature vector from the sample itself. This should only be implemented differently
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- if there are significant speedups to be gained from combining the two functions. '''
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- return self.process_raw_features(self.raw_features(bytez, lief_binary))
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-
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-
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-class ByteHistogram(FeatureType):
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- ''' Byte histogram (count + non-normalized) over the entire binary file '''
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-
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- name = 'histogram'
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- dim = 256
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-
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- def __init__(self):
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- super(FeatureType, self).__init__()
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-
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- def raw_features(self, bytez, lief_binary):
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- counts = np.bincount(np.frombuffer(bytez, dtype=np.uint8), minlength=256)
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- return counts.tolist()
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-
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- def process_raw_features(self, raw_obj):
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- counts = np.array(raw_obj, dtype=np.float32)
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- sum = counts.sum()
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- normalized = counts / sum
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- return normalized
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-
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-
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-class ByteEntropyHistogram(FeatureType):
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- ''' 2d byte/entropy histogram based loosely on (Saxe and Berlin, 2015).
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- This roughly approximates the joint probability of byte value and local entropy.
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- See Section 2.1.1 in https://arxiv.org/pdf/1508.03096.pdf for more info.
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- '''
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-
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- name = 'byteentropy'
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- dim = 256
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-
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- def __init__(self, step=1024, window=2048):
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- super(FeatureType, self).__init__()
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- self.window = window
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- self.step = step
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-
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- def _entropy_bin_counts(self, block):
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- # coarse histogram, 16 bytes per bin
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- c = np.bincount(block >> 4, minlength=16) # 16-bin histogram
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- p = c.astype(np.float32) / self.window
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- wh = np.where(c)[0]
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- H = np.sum(-p[wh] * np.log2(
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- p[wh])) * 2 # * x2 b.c. we reduced information by half: 256 bins (8 bits) to 16 bins (4 bits)
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-
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- Hbin = int(H * 2) # up to 16 bins (max entropy is 8 bits)
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- if Hbin == 16: # handle entropy = 8.0 bits
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- Hbin = 15
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-
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- return Hbin, c
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-
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- def raw_features(self, bytez, lief_binary):
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- output = np.zeros((16, 16), dtype=int)
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- a = np.frombuffer(bytez, dtype=np.uint8)
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- if a.shape[0] < self.window:
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- Hbin, c = self._entropy_bin_counts(a)
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- output[Hbin, :] += c
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- else:
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- # strided trick from here: http://www.rigtorp.se/2011/01/01/rolling-statistics-numpy.html
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- shape = a.shape[:-1] + (a.shape[-1] - self.window + 1, self.window)
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- strides = a.strides + (a.strides[-1],)
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- blocks = np.lib.stride_tricks.as_strided(a, shape=shape, strides=strides)[::self.step, :]
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-
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- # from the blocks, compute histogram
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- for block in blocks:
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- Hbin, c = self._entropy_bin_counts(block)
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- output[Hbin, :] += c
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-
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- return output.flatten().tolist()
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-
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- def process_raw_features(self, raw_obj):
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- counts = np.array(raw_obj, dtype=np.float32)
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- sum = counts.sum()
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- normalized = counts / sum
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- return normalized
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-
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-
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-class SectionInfo(FeatureType):
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- ''' Information about section names, sizes and entropy. Uses hashing trick
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- to summarize all this section info into a feature vector.
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- '''
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-
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- name = 'section'
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- dim = 5 + 50 + 50 + 50 + 50 + 50
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-
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- def __init__(self):
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- super(FeatureType, self).__init__()
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-
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- @staticmethod
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- def _properties(s):
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- return [str(c).split('.')[-1] for c in s.characteristics_lists]
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-
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- def raw_features(self, bytez, lief_binary):
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- if lief_binary is None:
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- return {"entry": "", "sections": []}
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-
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- # properties of entry point, or if invalid, the first executable section
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- not_found_error_class = RuntimeError if not lief.__version__.startswith("0.9.0") else lief.not_found
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- try:
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- if int(LIEF_MAJOR) > 0 or (int(LIEF_MAJOR) == 0 and int(LIEF_MINOR) >= 12):
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- section = lief_binary.section_from_rva(lief_binary.entrypoint - lief_binary.imagebase)
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-
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- if section is None:
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- raise not_found_error_class
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- entry_section = section.name
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- else: # lief < 0.12
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- entry_section = lief_binary.section_from_offset(lief_binary.entrypoint).name
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- except not_found_error_class:
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- # bad entry point, let's find the first executable section
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- entry_section = ""
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- mem_execute_characteristics = lief.PE.SECTION_CHARACTERISTICS.MEM_EXECUTE if lief.__version__.startswith("0.9.0") else lief.PE.Section.CHARACTERISTICS.MEM_EXECUTE
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- for s in lief_binary.sections:
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- if mem_execute_characteristics in s.characteristics_lists:
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- entry_section = s.name
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- break
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-
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- raw_obj = {"entry": entry_section}
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- raw_obj["sections"] = [{
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- 'name': s.name,
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- 'size': s.size,
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- 'entropy': s.entropy,
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- 'vsize': s.virtual_size,
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- 'props': self._properties(s)
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- } for s in lief_binary.sections]
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- return raw_obj
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-
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- def process_raw_features(self, raw_obj):
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- sections = raw_obj['sections']
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- general = [
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- len(sections), # total number of sections
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- # number of sections with zero size
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- sum(1 for s in sections if s['size'] == 0),
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- # number of sections with an empty name
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- sum(1 for s in sections if s['name'] == ""),
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- # number of RX
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- sum(1 for s in sections if 'MEM_READ' in s['props'] and 'MEM_EXECUTE' in s['props']),
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- # number of W
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- sum(1 for s in sections if 'MEM_WRITE' in s['props'])
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- ]
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- # gross characteristics of each section
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- section_sizes = [(s['name'], s['size']) for s in sections]
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- section_sizes_hashed = FeatureHasher(50, input_type="pair").transform([section_sizes]).toarray()[0]
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- section_entropy = [(s['name'], s['entropy']) for s in sections]
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- section_entropy_hashed = FeatureHasher(50, input_type="pair").transform([section_entropy]).toarray()[0]
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- section_vsize = [(s['name'], s['vsize']) for s in sections]
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- section_vsize_hashed = FeatureHasher(50, input_type="pair").transform([section_vsize]).toarray()[0]
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- entry_name_hashed = FeatureHasher(50, input_type="string").transform([[raw_obj['entry']]]).toarray()[0]
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- characteristics = [p for s in sections for p in s['props'] if s['name'] == raw_obj['entry']]
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- characteristics_hashed = FeatureHasher(50, input_type="string").transform([characteristics]).toarray()[0]
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-
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- return np.hstack([
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- general, section_sizes_hashed, section_entropy_hashed, section_vsize_hashed, entry_name_hashed,
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- characteristics_hashed
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- ]).astype(np.float32)
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-
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-
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-class ImportsInfo(FeatureType):
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- ''' Information about imported libraries and functions from the
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- import address table. Note that the total number of imported
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- functions is contained in GeneralFileInfo.
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- '''
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-
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- name = 'imports'
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- dim = 1280
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-
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- def __init__(self):
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- super(FeatureType, self).__init__()
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-
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- def raw_features(self, bytez, lief_binary):
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- imports = {}
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- if lief_binary is None:
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- return imports
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-
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- for lib in lief_binary.imports:
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- if lib.name not in imports:
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- imports[lib.name] = [] # libraries can be duplicated in listing, extend instead of overwrite
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-
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- # Clipping assumes there are diminishing returns on the discriminatory power of imported functions
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- # beyond the first 10000 characters, and this will help limit the dataset size
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- for entry in lib.entries:
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- if entry.is_ordinal:
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- imports[lib.name].append("ordinal" + str(entry.ordinal))
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- else:
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- imports[lib.name].append(entry.name[:10000])
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-
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- return imports
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-
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- def process_raw_features(self, raw_obj):
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- # unique libraries
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- libraries = list(set([l.lower() for l in raw_obj.keys()]))
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- libraries_hashed = FeatureHasher(256, input_type="string").transform([libraries]).toarray()[0]
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-
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- # A string like "kernel32.dll:CreateFileMappingA" for each imported function
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- imports = [lib.lower() + ':' + e for lib, elist in raw_obj.items() for e in elist]
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- imports_hashed = FeatureHasher(1024, input_type="string").transform([imports]).toarray()[0]
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-
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- # Two separate elements: libraries (alone) and fully-qualified names of imported functions
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- return np.hstack([libraries_hashed, imports_hashed]).astype(np.float32)
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-
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-
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-class ExportsInfo(FeatureType):
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- ''' Information about exported functions. Note that the total number of exported
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- functions is contained in GeneralFileInfo.
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- '''
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-
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- name = 'exports'
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- dim = 128
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-
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- def __init__(self):
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- super(FeatureType, self).__init__()
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-
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- def raw_features(self, bytez, lief_binary):
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- if lief_binary is None:
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- return []
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-
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- # Clipping assumes there are diminishing returns on the discriminatory power of exports beyond
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- # the first 10000 characters, and this will help limit the dataset size
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- if LIEF_EXPORT_OBJECT:
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- # export is an object with .name attribute (0.10.0 and later)
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- clipped_exports = [export.name[:10000] for export in lief_binary.exported_functions]
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- else:
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- # export is a string (LIEF 0.9.0 and earlier)
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- clipped_exports = [export[:10000] for export in lief_binary.exported_functions]
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-
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- return clipped_exports
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-
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- def process_raw_features(self, raw_obj):
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- exports_hashed = FeatureHasher(128, input_type="string").transform([raw_obj]).toarray()[0]
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- return exports_hashed.astype(np.float32)
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-
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-
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-class GeneralFileInfo(FeatureType):
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- ''' General information about the file '''
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-
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- name = 'general'
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- dim = 10
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-
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- def __init__(self):
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- super(FeatureType, self).__init__()
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-
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- def raw_features(self, bytez, lief_binary):
|
|
290
|
|
- if lief_binary is None:
|
|
291
|
|
- return {
|
|
292
|
|
- 'size': len(bytez),
|
|
293
|
|
- 'vsize': 0,
|
|
294
|
|
- 'has_debug': 0,
|
|
295
|
|
- 'exports': 0,
|
|
296
|
|
- 'imports': 0,
|
|
297
|
|
- 'has_relocations': 0,
|
|
298
|
|
- 'has_resources': 0,
|
|
299
|
|
- 'has_signature': 0,
|
|
300
|
|
- 'has_tls': 0,
|
|
301
|
|
- 'symbols': 0
|
|
302
|
|
- }
|
|
303
|
|
-
|
|
304
|
|
- return {
|
|
305
|
|
- 'size': len(bytez),
|
|
306
|
|
- 'vsize': lief_binary.virtual_size,
|
|
307
|
|
- 'has_debug': int(lief_binary.has_debug),
|
|
308
|
|
- 'exports': len(lief_binary.exported_functions),
|
|
309
|
|
- 'imports': len(lief_binary.imported_functions),
|
|
310
|
|
- 'has_relocations': int(lief_binary.has_relocations),
|
|
311
|
|
- 'has_resources': int(lief_binary.has_resources),
|
|
312
|
|
- 'has_signature': int(lief_binary.has_signatures) if LIEF_HAS_SIGNATURE else int(lief_binary.has_signature),
|
|
313
|
|
- 'has_tls': int(lief_binary.has_tls),
|
|
314
|
|
- 'symbols': len(lief_binary.symbols),
|
|
315
|
|
- }
|
|
316
|
|
-
|
|
317
|
|
- def process_raw_features(self, raw_obj):
|
|
318
|
|
- return np.asarray([
|
|
319
|
|
- raw_obj['size'], raw_obj['vsize'], raw_obj['has_debug'], raw_obj['exports'], raw_obj['imports'],
|
|
320
|
|
- raw_obj['has_relocations'], raw_obj['has_resources'], raw_obj['has_signature'], raw_obj['has_tls'],
|
|
321
|
|
- raw_obj['symbols']
|
|
322
|
|
- ],
|
|
323
|
|
- dtype=np.float32)
|
|
324
|
|
-
|
|
325
|
|
-
|
|
326
|
|
-class HeaderFileInfo(FeatureType):
|
|
327
|
|
- ''' Machine, architecure, OS, linker and other information extracted from header '''
|
|
328
|
|
-
|
|
329
|
|
- name = 'header'
|
|
330
|
|
- dim = 62
|
|
331
|
|
-
|
|
332
|
|
- def __init__(self):
|
|
333
|
|
- super(FeatureType, self).__init__()
|
|
334
|
|
-
|
|
335
|
|
- def raw_features(self, bytez, lief_binary):
|
|
336
|
|
- raw_obj = {}
|
|
337
|
|
- raw_obj['coff'] = {'timestamp': 0, 'machine': "", 'characteristics': []}
|
|
338
|
|
- raw_obj['optional'] = {
|
|
339
|
|
- 'subsystem': "",
|
|
340
|
|
- 'dll_characteristics': [],
|
|
341
|
|
- 'magic': "",
|
|
342
|
|
- 'major_image_version': 0,
|
|
343
|
|
- 'minor_image_version': 0,
|
|
344
|
|
- 'major_linker_version': 0,
|
|
345
|
|
- 'minor_linker_version': 0,
|
|
346
|
|
- 'major_operating_system_version': 0,
|
|
347
|
|
- 'minor_operating_system_version': 0,
|
|
348
|
|
- 'major_subsystem_version': 0,
|
|
349
|
|
- 'minor_subsystem_version': 0,
|
|
350
|
|
- 'sizeof_code': 0,
|
|
351
|
|
- 'sizeof_headers': 0,
|
|
352
|
|
- 'sizeof_heap_commit': 0
|
|
353
|
|
- }
|
|
354
|
|
- if lief_binary is None:
|
|
355
|
|
- return raw_obj
|
|
356
|
|
-
|
|
357
|
|
- raw_obj['coff']['timestamp'] = lief_binary.header.time_date_stamps
|
|
358
|
|
- raw_obj['coff']['machine'] = str(lief_binary.header.machine).split('.')[-1]
|
|
359
|
|
- raw_obj['coff']['characteristics'] = [str(c).split('.')[-1] for c in lief_binary.header.characteristics_list]
|
|
360
|
|
- raw_obj['optional']['subsystem'] = str(lief_binary.optional_header.subsystem).split('.')[-1]
|
|
361
|
|
- raw_obj['optional']['dll_characteristics'] = [
|
|
362
|
|
- str(c).split('.')[-1] for c in lief_binary.optional_header.dll_characteristics_lists
|
|
363
|
|
- ]
|
|
364
|
|
- raw_obj['optional']['magic'] = str(lief_binary.optional_header.magic).split('.')[-1]
|
|
365
|
|
- raw_obj['optional']['major_image_version'] = lief_binary.optional_header.major_image_version
|
|
366
|
|
- raw_obj['optional']['minor_image_version'] = lief_binary.optional_header.minor_image_version
|
|
367
|
|
- raw_obj['optional']['major_linker_version'] = lief_binary.optional_header.major_linker_version
|
|
368
|
|
- raw_obj['optional']['minor_linker_version'] = lief_binary.optional_header.minor_linker_version
|
|
369
|
|
- raw_obj['optional'][
|
|
370
|
|
- 'major_operating_system_version'] = lief_binary.optional_header.major_operating_system_version
|
|
371
|
|
- raw_obj['optional'][
|
|
372
|
|
- 'minor_operating_system_version'] = lief_binary.optional_header.minor_operating_system_version
|
|
373
|
|
- raw_obj['optional']['major_subsystem_version'] = lief_binary.optional_header.major_subsystem_version
|
|
374
|
|
- raw_obj['optional']['minor_subsystem_version'] = lief_binary.optional_header.minor_subsystem_version
|
|
375
|
|
- raw_obj['optional']['sizeof_code'] = lief_binary.optional_header.sizeof_code
|
|
376
|
|
- raw_obj['optional']['sizeof_headers'] = lief_binary.optional_header.sizeof_headers
|
|
377
|
|
- raw_obj['optional']['sizeof_heap_commit'] = lief_binary.optional_header.sizeof_heap_commit
|
|
378
|
|
- return raw_obj
|
|
379
|
|
-
|
|
380
|
|
- def process_raw_features(self, raw_obj):
|
|
381
|
|
- return np.hstack([
|
|
382
|
|
- raw_obj['coff']['timestamp'],
|
|
383
|
|
- FeatureHasher(10, input_type="string").transform([[raw_obj['coff']['machine']]]).toarray()[0],
|
|
384
|
|
- FeatureHasher(10, input_type="string").transform([raw_obj['coff']['characteristics']]).toarray()[0],
|
|
385
|
|
- FeatureHasher(10, input_type="string").transform([[raw_obj['optional']['subsystem']]]).toarray()[0],
|
|
386
|
|
- FeatureHasher(10, input_type="string").transform([raw_obj['optional']['dll_characteristics']]).toarray()[0],
|
|
387
|
|
- FeatureHasher(10, input_type="string").transform([[raw_obj['optional']['magic']]]).toarray()[0],
|
|
388
|
|
- raw_obj['optional']['major_image_version'],
|
|
389
|
|
- raw_obj['optional']['minor_image_version'],
|
|
390
|
|
- raw_obj['optional']['major_linker_version'],
|
|
391
|
|
- raw_obj['optional']['minor_linker_version'],
|
|
392
|
|
- raw_obj['optional']['major_operating_system_version'],
|
|
393
|
|
- raw_obj['optional']['minor_operating_system_version'],
|
|
394
|
|
- raw_obj['optional']['major_subsystem_version'],
|
|
395
|
|
- raw_obj['optional']['minor_subsystem_version'],
|
|
396
|
|
- raw_obj['optional']['sizeof_code'],
|
|
397
|
|
- raw_obj['optional']['sizeof_headers'],
|
|
398
|
|
- raw_obj['optional']['sizeof_heap_commit'],
|
|
399
|
|
- ]).astype(np.float32)
|
|
400
|
|
-
|
|
401
|
|
-
|
|
402
|
|
-class StringExtractor(FeatureType):
|
|
403
|
|
- ''' Extracts strings from raw byte stream '''
|
|
404
|
|
-
|
|
405
|
|
- name = 'strings'
|
|
406
|
|
- dim = 1 + 1 + 1 + 96 + 1 + 1 + 1 + 1 + 1
|
|
407
|
|
-
|
|
408
|
|
- def __init__(self):
|
|
409
|
|
- super(FeatureType, self).__init__()
|
|
410
|
|
- # all consecutive runs of 0x20 - 0x7f that are 5+ characters
|
|
411
|
|
- self._allstrings = re.compile(b'[\x20-\x7f]{5,}')
|
|
412
|
|
- # occurances of the string 'C:\'. Not actually extracting the path
|
|
413
|
|
- self._paths = re.compile(b'c:\\\\', re.IGNORECASE)
|
|
414
|
|
- # occurances of http:// or https://. Not actually extracting the URLs
|
|
415
|
|
- self._urls = re.compile(b'https?://', re.IGNORECASE)
|
|
416
|
|
- # occurances of the string prefix HKEY_. No actually extracting registry names
|
|
417
|
|
- self._registry = re.compile(b'HKEY_')
|
|
418
|
|
- # crude evidence of an MZ header (dropper?) somewhere in the byte stream
|
|
419
|
|
- self._mz = re.compile(b'MZ')
|
|
420
|
|
-
|
|
421
|
|
- def raw_features(self, bytez, lief_binary):
|
|
422
|
|
- allstrings = self._allstrings.findall(bytez)
|
|
423
|
|
- if allstrings:
|
|
424
|
|
- # statistics about strings:
|
|
425
|
|
- string_lengths = [len(s) for s in allstrings]
|
|
426
|
|
- avlength = sum(string_lengths) / len(string_lengths)
|
|
427
|
|
- # map printable characters 0x20 - 0x7f to an int array consisting of 0-95, inclusive
|
|
428
|
|
- as_shifted_string = [b - ord(b'\x20') for b in b''.join(allstrings)]
|
|
429
|
|
- c = np.bincount(as_shifted_string, minlength=96) # histogram count
|
|
430
|
|
- # distribution of characters in printable strings
|
|
431
|
|
- csum = c.sum()
|
|
432
|
|
- p = c.astype(np.float32) / csum
|
|
433
|
|
- wh = np.where(c)[0]
|
|
434
|
|
- H = np.sum(-p[wh] * np.log2(p[wh])) # entropy
|
|
435
|
|
- else:
|
|
436
|
|
- avlength = 0
|
|
437
|
|
- c = np.zeros((96,), dtype=np.float32)
|
|
438
|
|
- H = 0
|
|
439
|
|
- csum = 0
|
|
440
|
|
-
|
|
441
|
|
- return {
|
|
442
|
|
- 'numstrings': len(allstrings),
|
|
443
|
|
- 'avlength': avlength,
|
|
444
|
|
- 'printabledist': c.tolist(), # store non-normalized histogram
|
|
445
|
|
- 'printables': int(csum),
|
|
446
|
|
- 'entropy': float(H),
|
|
447
|
|
- 'paths': len(self._paths.findall(bytez)),
|
|
448
|
|
- 'urls': len(self._urls.findall(bytez)),
|
|
449
|
|
- 'registry': len(self._registry.findall(bytez)),
|
|
450
|
|
- 'MZ': len(self._mz.findall(bytez))
|
|
451
|
|
- }
|
|
452
|
|
-
|
|
453
|
|
- def process_raw_features(self, raw_obj):
|
|
454
|
|
- hist_divisor = float(raw_obj['printables']) if raw_obj['printables'] > 0 else 1.0
|
|
455
|
|
- return np.hstack([
|
|
456
|
|
- raw_obj['numstrings'], raw_obj['avlength'], raw_obj['printables'],
|
|
457
|
|
- np.asarray(raw_obj['printabledist']) / hist_divisor, raw_obj['entropy'], raw_obj['paths'], raw_obj['urls'],
|
|
458
|
|
- raw_obj['registry'], raw_obj['MZ']
|
|
459
|
|
- ]).astype(np.float32)
|
|
460
|
|
-
|
|
461
|
|
-
|
|
462
|
|
-class DataDirectories(FeatureType):
|
|
463
|
|
- ''' Extracts size and virtual address of the first 15 data directories '''
|
|
464
|
|
-
|
|
465
|
|
- name = 'datadirectories'
|
|
466
|
|
- dim = 15 * 2
|
|
467
|
|
-
|
|
468
|
|
- def __init__(self):
|
|
469
|
|
- super(FeatureType, self).__init__()
|
|
470
|
|
- self._name_order = [
|
|
471
|
|
- "EXPORT_TABLE", "IMPORT_TABLE", "RESOURCE_TABLE", "EXCEPTION_TABLE", "CERTIFICATE_TABLE",
|
|
472
|
|
- "BASE_RELOCATION_TABLE", "DEBUG", "ARCHITECTURE", "GLOBAL_PTR", "TLS_TABLE", "LOAD_CONFIG_TABLE",
|
|
473
|
|
- "BOUND_IMPORT", "IAT", "DELAY_IMPORT_DESCRIPTOR", "CLR_RUNTIME_HEADER"
|
|
474
|
|
- ]
|
|
475
|
|
-
|
|
476
|
|
- def raw_features(self, bytez, lief_binary):
|
|
477
|
|
- output = []
|
|
478
|
|
- if lief_binary is None:
|
|
479
|
|
- return output
|
|
480
|
|
-
|
|
481
|
|
- for data_directory in lief_binary.data_directories:
|
|
482
|
|
- output.append({
|
|
483
|
|
- "name": str(data_directory.type).replace("DATA_DIRECTORY.", ""),
|
|
484
|
|
- "size": data_directory.size,
|
|
485
|
|
- "virtual_address": data_directory.rva
|
|
486
|
|
- })
|
|
487
|
|
- return output
|
|
488
|
|
-
|
|
489
|
|
- def process_raw_features(self, raw_obj):
|
|
490
|
|
- features = np.zeros(2 * len(self._name_order), dtype=np.float32)
|
|
491
|
|
- for i in range(len(self._name_order)):
|
|
492
|
|
- if i < len(raw_obj):
|
|
493
|
|
- features[2 * i] = raw_obj[i]["size"]
|
|
494
|
|
- features[2 * i + 1] = raw_obj[i]["virtual_address"]
|
|
495
|
|
- return features
|
|
496
|
|
-
|
|
497
|
|
-
|
|
498
|
|
-class EMBERFeatureExtractor(object):
|
|
499
|
|
- ''' Extract useful features from a PE file, and return as a vector of fixed size. '''
|
|
500
|
|
-
|
|
501
|
|
- def __init__(self, feature_version=2, print_feature_warning=True, features_file=''):
|
|
502
|
|
- self.features = []
|
|
503
|
|
- features = {
|
|
504
|
|
- 'ByteHistogram': ByteHistogram(),
|
|
505
|
|
- 'ByteEntropyHistogram': ByteEntropyHistogram(),
|
|
506
|
|
- 'StringExtractor': StringExtractor(),
|
|
507
|
|
- 'GeneralFileInfo': GeneralFileInfo(),
|
|
508
|
|
- 'HeaderFileInfo': HeaderFileInfo(),
|
|
509
|
|
- 'SectionInfo': SectionInfo(),
|
|
510
|
|
- 'ImportsInfo': ImportsInfo(),
|
|
511
|
|
- 'ExportsInfo': ExportsInfo()
|
|
512
|
|
- }
|
|
513
|
|
-
|
|
514
|
|
- if os.path.exists(features_file):
|
|
515
|
|
- with open(features_file, encoding='utf8') as f:
|
|
516
|
|
- x = json.load(f)
|
|
517
|
|
- self.features = [features[feature] for feature in x['features'] if feature in features]
|
|
518
|
|
- else:
|
|
519
|
|
- self.features = list(features.values())
|
|
520
|
|
-
|
|
521
|
|
- if feature_version == 1:
|
|
522
|
|
- if not lief.__version__.startswith("0.8.3"):
|
|
523
|
|
- if print_feature_warning:
|
|
524
|
|
- print(f"WARNING: EMBER feature version 1 were computed using lief version 0.8.3-18d5b75")
|
|
525
|
|
- print(
|
|
526
|
|
- f"WARNING: lief version {lief.__version__} found instead. There may be slight inconsistencies")
|
|
527
|
|
- print(f"WARNING: in the feature calculations.")
|
|
528
|
|
- elif feature_version == 2:
|
|
529
|
|
- self.features.append(DataDirectories())
|
|
530
|
|
- if not lief.__version__.startswith("0.9.0"):
|
|
531
|
|
- if print_feature_warning:
|
|
532
|
|
- print(f"WARNING: EMBER feature version 2 were computed using lief version 0.9.0-")
|
|
533
|
|
- print(
|
|
534
|
|
- f"WARNING: lief version {lief.__version__} found instead. There may be slight inconsistencies")
|
|
535
|
|
- print(f"WARNING: in the feature calculations.")
|
|
536
|
|
- else:
|
|
537
|
|
- raise Exception(f"EMBER feature version must be 1 or 2. Not {feature_version}")
|
|
538
|
|
- self.dim = sum([fe.dim for fe in self.features])
|
|
539
|
|
-
|
|
540
|
|
- def raw_features(self, bytez):
|
|
541
|
|
- if lief.__version__.startswith("0.9.0"):
|
|
542
|
|
- lief_errors = (
|
|
543
|
|
- lief.bad_format, lief.bad_file, lief.pe_error, lief.parser_error, lief.read_out_of_bound, RuntimeError)
|
|
544
|
|
- else:
|
|
545
|
|
- lief_errors = (
|
|
546
|
|
- lief.lief_errors.conversion_error, lief.lief_errors.file_error, lief.lief_errors.file_format_error,
|
|
547
|
|
- lief.lief_errors.corrupted, lief.lief_errors.parsing_error, lief.lief_errors.read_out_of_bound,
|
|
548
|
|
- RuntimeError)
|
|
549
|
|
-
|
|
550
|
|
- try:
|
|
551
|
|
- lief_binary = lief.PE.parse(list(bytez))
|
|
552
|
|
- except lief_errors as e:
|
|
553
|
|
- print("lief error: ", str(e))
|
|
554
|
|
- lief_binary = None
|
|
555
|
|
- except Exception: # everything else (KeyboardInterrupt, SystemExit, ValueError):
|
|
556
|
|
- raise
|
|
557
|
|
-
|
|
558
|
|
- features = {"sha256": hashlib.sha256(bytez).hexdigest()}
|
|
559
|
|
- features.update({fe.name: fe.raw_features(bytez, lief_binary) for fe in self.features})
|
|
560
|
|
- return features
|
|
561
|
|
-
|
|
562
|
|
- def process_raw_features(self, raw_obj):
|
|
563
|
|
- feature_vectors = [fe.process_raw_features(raw_obj[fe.name]) for fe in self.features]
|
|
564
|
|
- return np.hstack(feature_vectors).astype(np.float32)
|
|
565
|
|
-
|
|
566
|
|
- def feature_vector(self, bytez):
|
|
567
|
|
- return self.process_raw_features(self.raw_features(bytez))
|