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https://github.com/mandiant/capa.git
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306 lines
14 KiB
Python
306 lines
14 KiB
Python
import viv_utils
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import capa.features
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import capa.features.file
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import capa.features.insn
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import capa.features.function
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import capa.features.basicblock
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import capa.features.extractors.viv.file
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import capa.features.extractors.viv.insn
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import capa.features.extractors.viv.function
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import capa.features.extractors.viv.basicblock
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from fixtures import *
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def extract_file_features(vw, path):
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features = set([])
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for feature, va in capa.features.extractors.viv.file.extract_features(vw, path):
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features.add(feature)
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return features
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def extract_function_features(f):
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features = collections.defaultdict(set)
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for bb in f.basic_blocks:
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for insn in bb.instructions:
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for feature, va in capa.features.extractors.viv.insn.extract_features(f, bb, insn):
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features[feature].add(va)
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for feature, va in capa.features.extractors.viv.basicblock.extract_features(f, bb):
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features[feature].add(va)
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for feature, va in capa.features.extractors.viv.function.extract_features(f):
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features[feature].add(va)
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return features
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def extract_basic_block_features(f, bb):
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features = set({})
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for insn in bb.instructions:
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for feature, _ in capa.features.extractors.viv.insn.extract_features(f, bb, insn):
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features.add(feature)
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for feature, _ in capa.features.extractors.viv.basicblock.extract_features(f, bb):
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features.add(feature)
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return features
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def test_api_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x403BAC))
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assert capa.features.insn.API("advapi32.CryptAcquireContextW") in features
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assert capa.features.insn.API("advapi32.CryptAcquireContext") in features
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assert capa.features.insn.API("advapi32.CryptGenKey") in features
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assert capa.features.insn.API("advapi32.CryptImportKey") in features
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assert capa.features.insn.API("advapi32.CryptDestroyKey") in features
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assert capa.features.insn.API("CryptAcquireContextW") in features
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assert capa.features.insn.API("CryptAcquireContext") in features
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assert capa.features.insn.API("CryptGenKey") in features
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assert capa.features.insn.API("CryptImportKey") in features
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assert capa.features.insn.API("CryptDestroyKey") in features
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def test_api_features_64_bit(sample_a198216798ca38f280dc413f8c57f2c2):
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features = extract_function_features(viv_utils.Function(sample_a198216798ca38f280dc413f8c57f2c2.vw, 0x4011B0))
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assert capa.features.insn.API("kernel32.GetStringTypeA") in features
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assert capa.features.insn.API("kernel32.GetStringTypeW") not in features
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assert capa.features.insn.API("kernel32.GetStringType") in features
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assert capa.features.insn.API("GetStringTypeA") in features
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assert capa.features.insn.API("GetStringType") in features
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# call via thunk in IDA Pro
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features = extract_function_features(viv_utils.Function(sample_a198216798ca38f280dc413f8c57f2c2.vw, 0x401CB0))
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assert capa.features.insn.API("msvcrt.vfprintf") in features
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assert capa.features.insn.API("vfprintf") in features
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def test_string_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x40105D))
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assert capa.features.String("SCardControl") in features
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assert capa.features.String("SCardTransmit") in features
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assert capa.features.String("ACR > ") in features
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# other strings not in this function
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assert capa.features.String("bcrypt.dll") not in features
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def test_byte_features(sample_9324d1a8ae37a36ae560c37448c9705a):
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features = extract_function_features(viv_utils.Function(sample_9324d1a8ae37a36ae560c37448c9705a.vw, 0x406F60))
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wanted = capa.features.Bytes(b"\xED\x24\x9E\xF4\x52\xA9\x07\x47\x55\x8E\xE1\xAB\x30\x8E\x23\x61")
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# use `==` rather than `is` because the result is not `True` but a truthy value.
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assert wanted.evaluate(features) == True
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def test_byte_features64(sample_lab21_01):
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features = extract_function_features(viv_utils.Function(sample_lab21_01.vw, 0x1400010C0))
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wanted = capa.features.Bytes(b"\x32\xA2\xDF\x2D\x99\x2B\x00\x00")
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# use `==` rather than `is` because the result is not `True` but a truthy value.
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assert wanted.evaluate(features) == True
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def test_number_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x40105D))
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assert capa.features.insn.Number(0xFF) in features
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assert capa.features.insn.Number(0x3136B0) in features
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# the following are stack adjustments
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assert capa.features.insn.Number(0xC) not in features
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assert capa.features.insn.Number(0x10) not in features
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def test_offset_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x40105D))
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assert capa.features.insn.Offset(0x0) in features
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assert capa.features.insn.Offset(0x4) in features
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assert capa.features.insn.Offset(0xC) in features
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# the following are stack references
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assert capa.features.insn.Offset(0x8) not in features
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assert capa.features.insn.Offset(0x10) not in features
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def test_nzxor_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x410DFC))
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assert capa.features.Characteristic("nzxor") in features # 0x0410F0B
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def get_bb_insn(f, va):
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"""fetch the BasicBlock and Instruction instances for the given VA in the given function."""
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for bb in f.basic_blocks:
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for insn in bb.instructions:
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if insn.va == va:
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return (bb, insn)
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raise KeyError(va)
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def test_is_security_cookie(mimikatz):
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# not a security cookie check
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f = viv_utils.Function(mimikatz.vw, 0x410DFC)
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for va in [0x0410F0B]:
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bb, insn = get_bb_insn(f, va)
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assert capa.features.extractors.viv.insn.is_security_cookie(f, bb, insn) == False
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# security cookie initial set and final check
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f = viv_utils.Function(mimikatz.vw, 0x46C54A)
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for va in [0x46C557, 0x46C63A]:
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bb, insn = get_bb_insn(f, va)
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assert capa.features.extractors.viv.insn.is_security_cookie(f, bb, insn) == True
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def test_mnemonic_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x40105D))
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assert capa.features.insn.Mnemonic("push") in features
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assert capa.features.insn.Mnemonic("movzx") in features
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assert capa.features.insn.Mnemonic("xor") in features
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assert capa.features.insn.Mnemonic("in") not in features
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assert capa.features.insn.Mnemonic("out") not in features
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def test_peb_access_features(sample_a933a1a402775cfa94b6bee0963f4b46):
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features = extract_function_features(viv_utils.Function(sample_a933a1a402775cfa94b6bee0963f4b46.vw, 0xABA6FEC))
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assert capa.features.Characteristic("peb access") in features
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def test_file_section_name_features(mimikatz):
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features = extract_file_features(mimikatz.vw, mimikatz.path)
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assert capa.features.file.Section(".rsrc") in features
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assert capa.features.file.Section(".text") in features
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assert capa.features.file.Section(".nope") not in features
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def test_tight_loop_features(mimikatz):
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f = viv_utils.Function(mimikatz.vw, 0x402EC4)
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for bb in f.basic_blocks:
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if bb.va != 0x402F8E:
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continue
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features = extract_basic_block_features(f, bb)
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assert capa.features.Characteristic("tight loop") in features
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assert capa.features.basicblock.BasicBlock() in features
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def test_tight_loop_bb_features(mimikatz):
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f = viv_utils.Function(mimikatz.vw, 0x402EC4)
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for bb in f.basic_blocks:
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if bb.va != 0x402F8E:
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continue
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features = extract_basic_block_features(f, bb)
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assert capa.features.Characteristic("tight loop") in features
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assert capa.features.basicblock.BasicBlock() in features
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def test_file_export_name_features(kernel32):
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features = extract_file_features(kernel32.vw, kernel32.path)
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assert capa.features.file.Export("BaseThreadInitThunk") in features
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assert capa.features.file.Export("lstrlenW") in features
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def test_file_import_name_features(mimikatz):
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features = extract_file_features(mimikatz.vw, mimikatz.path)
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assert capa.features.file.Import("advapi32.CryptSetHashParam") in features
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assert capa.features.file.Import("CryptSetHashParam") in features
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assert capa.features.file.Import("kernel32.IsWow64Process") in features
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assert capa.features.file.Import("msvcrt.exit") in features
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assert capa.features.file.Import("cabinet.#11") in features
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assert capa.features.file.Import("#11") not in features
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def test_cross_section_flow_features(sample_a198216798ca38f280dc413f8c57f2c2):
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features = extract_function_features(viv_utils.Function(sample_a198216798ca38f280dc413f8c57f2c2.vw, 0x4014D0))
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assert capa.features.Characteristic("cross section flow") in features
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# this function has calls to some imports,
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# which should not trigger cross-section flow characteristic
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features = extract_function_features(viv_utils.Function(sample_a198216798ca38f280dc413f8c57f2c2.vw, 0x401563))
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assert capa.features.Characteristic("cross section flow") not in features
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def test_segment_access_features(sample_a933a1a402775cfa94b6bee0963f4b46):
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features = extract_function_features(viv_utils.Function(sample_a933a1a402775cfa94b6bee0963f4b46.vw, 0xABA6FEC))
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assert capa.features.Characteristic("fs access") in features
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def test_thunk_features(sample_9324d1a8ae37a36ae560c37448c9705a):
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features = extract_function_features(viv_utils.Function(sample_9324d1a8ae37a36ae560c37448c9705a.vw, 0x407970))
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assert capa.features.insn.API("kernel32.CreateToolhelp32Snapshot") in features
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assert capa.features.insn.API("CreateToolhelp32Snapshot") in features
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def test_file_embedded_pe(pma_lab_12_04):
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features = extract_file_features(pma_lab_12_04.vw, pma_lab_12_04.path)
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assert capa.features.Characteristic("embedded pe") in features
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def test_stackstring_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x4556E5))
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assert capa.features.Characteristic("stack string") in features
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def test_switch_features(mimikatz):
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x409411))
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assert capa.features.Characteristic("switch") in features
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features = extract_function_features(viv_utils.Function(mimikatz.vw, 0x409393))
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assert capa.features.Characteristic("switch") not in features
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def test_recursive_call_feature(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41):
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features = extract_function_features(
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viv_utils.Function(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41.vw, 0x10003100)
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)
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assert capa.features.Characteristic("recursive call") in features
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features = extract_function_features(
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viv_utils.Function(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41.vw, 0x10007B00)
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)
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assert capa.features.Characteristic("recursive call") not in features
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def test_loop_feature(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41):
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features = extract_function_features(
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viv_utils.Function(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41.vw, 0x10003D30)
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)
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assert capa.features.Characteristic("loop") in features
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features = extract_function_features(
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viv_utils.Function(sample_39c05b15e9834ac93f206bc114d0a00c357c888db567ba8f5345da0529cbed41.vw, 0x10007250)
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)
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assert capa.features.Characteristic("loop") not in features
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def test_file_string_features(sample_bfb9b5391a13d0afd787e87ab90f14f5):
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features = extract_file_features(
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sample_bfb9b5391a13d0afd787e87ab90f14f5.vw, sample_bfb9b5391a13d0afd787e87ab90f14f5.path,
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)
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assert capa.features.String("WarStop") in features # ASCII, offset 0x40EC
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assert capa.features.String("cimage/png") in features # UTF-16 LE, offset 0x350E
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def test_function_calls_to(sample_9324d1a8ae37a36ae560c37448c9705a):
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features = extract_function_features(viv_utils.Function(sample_9324d1a8ae37a36ae560c37448c9705a.vw, 0x406F60))
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assert capa.features.Characteristic("calls to") in features
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assert len(features[capa.features.Characteristic("calls to")]) == 1
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def test_function_calls_to64(sample_lab21_01):
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features = extract_function_features(viv_utils.Function(sample_lab21_01.vw, 0x1400052D0)) # memcpy
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assert capa.features.Characteristic("calls to") in features
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assert len(features[capa.features.Characteristic("calls to")]) == 8
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def test_function_calls_from(sample_9324d1a8ae37a36ae560c37448c9705a):
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features = extract_function_features(viv_utils.Function(sample_9324d1a8ae37a36ae560c37448c9705a.vw, 0x406F60))
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assert capa.features.Characteristic("calls from") in features
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assert len(features[capa.features.Characteristic("calls from")]) == 23
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def test_basic_block_count(sample_9324d1a8ae37a36ae560c37448c9705a):
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features = extract_function_features(viv_utils.Function(sample_9324d1a8ae37a36ae560c37448c9705a.vw, 0x406F60))
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assert len(features[capa.features.basicblock.BasicBlock()]) == 26
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def test_indirect_call_features(sample_a933a1a402775cfa94b6bee0963f4b46):
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features = extract_function_features(viv_utils.Function(sample_a933a1a402775cfa94b6bee0963f4b46.vw, 0xABA68A0))
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assert capa.features.Characteristic("indirect call") in features
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assert len(features[capa.features.Characteristic("indirect call")]) == 3
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def test_indirect_calls_resolved(sample_c91887d861d9bd4a5872249b641bc9f9):
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features = extract_function_features(viv_utils.Function(sample_c91887d861d9bd4a5872249b641bc9f9.vw, 0x401A77))
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assert capa.features.insn.API("kernel32.CreatePipe") in features
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assert capa.features.insn.API("kernel32.SetHandleInformation") in features
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assert capa.features.insn.API("kernel32.CloseHandle") in features
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assert capa.features.insn.API("kernel32.WriteFile") in features
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