def test_hex():
exp_and = stix2.AndBooleanExpression([stix2.EqualityComparisonExpression("file:mime_type",
"image/bmp"),
stix2.EqualityComparisonExpression("file:magic_number_hex",
stix2.HexConstant("ffd8"))])
exp = stix2.ObservationExpression(exp_and)
assert str(exp) == "[file:mime_type = 'image/bmp' AND file:magic_number_hex = h'ffd8']"
def test_invalid_and_observable_expression():
with pytest.raises(ValueError) as excinfo:
stix2.AndBooleanExpression([stix2.EqualityComparisonExpression("user-account:display_name",
"admin"),
stix2.EqualityComparisonExpression("email-addr:display_name",
stix2.StringConstant("admin"))])
assert "All operands to an 'AND' expression must have the same object type" in str(excinfo)
def test_multiple_file_observable_expression(observation_class, op):
exp1 = stix2.EqualityComparisonExpression(
"file:hashes.'SHA-256'",
stix2.HashConstant(
"bf07a7fbb825fc0aae7bf4a1177b2b31fcf8a3feeaf7092761e18c859ee52a9c",
'SHA-256',
),
)
exp2 = stix2.EqualityComparisonExpression(
"file:hashes.MD5",
stix2.HashConstant("cead3f77f6cda6ec00f57d76c9a6879f", "MD5"),
)
bool1_exp = stix2.OrBooleanExpression([exp1, exp2])
exp3 = stix2.EqualityComparisonExpression(
"file:hashes.'SHA-256'",
stix2.HashConstant(
"aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f",
'SHA-256',
),
)
op1_exp = stix2.ObservationExpression(bool1_exp)
op2_exp = stix2.ObservationExpression(exp3)
exp = observation_class([op1_exp, op2_exp])
assert str(
exp
) == "[file:hashes.'SHA-256' = 'bf07a7fbb825fc0aae7bf4a1177b2b31fcf8a3feeaf7092761e18c859ee52a9c' OR file:hashes.MD5 = 'cead3f77f6cda6ec00f57d76c9a6879f'] {} [file:hashes.'SHA-256' = 'aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f']".format(
op) # noqa
def test_root_types():
ast = stix2.ObservationExpression(
stix2.AndBooleanExpression(
[stix2.ParentheticalExpression(
stix2.OrBooleanExpression([
stix2.EqualityComparisonExpression("a:b", stix2.StringConstant("1")),
stix2.EqualityComparisonExpression("b:c", stix2.StringConstant("2"))])),
stix2.EqualityComparisonExpression(u"b:d", stix2.StringConstant("3"))]))
assert str(ast) == "[(a:b = '1' OR b:c = '2') AND b:d = '3']"
def test_file_observable_expression():
exp1 = stix2.EqualityComparisonExpression("file:hashes.'SHA-256'",
stix2.HashConstant(
"aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f",
'SHA-256'))
exp2 = stix2.EqualityComparisonExpression("file:mime_type", stix2.StringConstant("application/x-pdf"))
bool_exp = stix2.AndBooleanExpression([exp1, exp2])
exp = stix2.ObservationExpression(bool_exp)
assert str(exp) == "[file:hashes.'SHA-256' = 'aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f' AND file:mime_type = 'application/x-pdf']" # noqa
def test_multiple_qualifiers():
exp_and = stix2.AndBooleanExpression([stix2.EqualityComparisonExpression("network-traffic:dst_ref.type",
"domain-name"),
stix2.EqualityComparisonExpression("network-traffic:dst_ref.value",
"example.com")])
exp_ob = stix2.ObservationExpression(exp_and)
qual_rep = stix2.RepeatQualifier(5)
qual_within = stix2.WithinQualifier(stix2.IntegerConstant(1800))
exp = stix2.QualifiedObservationExpression(stix2.QualifiedObservationExpression(exp_ob, qual_rep), qual_within)
assert str(exp) == "[network-traffic:dst_ref.type = 'domain-name' AND network-traffic:dst_ref.value = 'example.com'] REPEATS 5 TIMES WITHIN 1800 SECONDS" # noqa
def test_and_observable_expression():
exp1 = stix2.AndBooleanExpression([
stix2.EqualityComparisonExpression("user-account:account_type",
"unix"),
stix2.EqualityComparisonExpression("user-account:user_id",
stix2.StringConstant("1007")),
stix2.EqualityComparisonExpression("user-account:account_login",
"Peter")
])
exp2 = stix2.AndBooleanExpression([
stix2.EqualityComparisonExpression("user-account:account_type",
"unix"),
stix2.EqualityComparisonExpression("user-account:user_id",
stix2.StringConstant("1008")),
stix2.EqualityComparisonExpression("user-account:account_login",
"Paul")
])
exp3 = stix2.AndBooleanExpression([
stix2.EqualityComparisonExpression("user-account:account_type",
"unix"),
stix2.EqualityComparisonExpression("user-account:user_id",
stix2.StringConstant("1009")),
stix2.EqualityComparisonExpression("user-account:account_login",
"Mary")
])
exp = stix2.AndObservationExpression([
stix2.ObservationExpression(exp1),
stix2.ObservationExpression(exp2),
stix2.ObservationExpression(exp3)
])
assert str(
exp
) == "[user-account:account_type = 'unix' AND user-account:user_id = '1007' AND user-account:account_login = '******'] AND [user-account:account_type = 'unix' AND user-account:user_id = '1008' AND user-account:account_login = '******'] AND [user-account:account_type = 'unix' AND user-account:user_id = '1009' AND user-account:account_login = '******']" # noqa
def test_invalid_and_observable_expression():
with pytest.raises(ValueError):
stix2.AndBooleanExpression([
stix2.EqualityComparisonExpression(
"user-account:display_name",
"admin",
),
stix2.EqualityComparisonExpression(
"email-addr:display_name",
stix2.StringConstant("admin"),
),
])
def test_hash_followed_by_registryKey_expression():
hash_exp = stix2.EqualityComparisonExpression("file:hashes.MD5",
stix2.HashConstant("79054025255fb1a26e4bc422aef54eb4", "MD5"))
o_exp1 = stix2.ObservationExpression(hash_exp)
reg_exp = stix2.EqualityComparisonExpression(stix2.ObjectPath("windows-registry-key", ["key"]),
stix2.StringConstant("HKEY_LOCAL_MACHINE\\foo\\bar"))
o_exp2 = stix2.ObservationExpression(reg_exp)
fb_exp = stix2.FollowedByObservationExpression([o_exp1, o_exp2])
para_exp = stix2.ParentheticalExpression(fb_exp)
qual_exp = stix2.WithinQualifier(stix2.IntegerConstant(300))
exp = stix2.QualifiedObservationExpression(para_exp, qual_exp)
assert str(exp) == "([file:hashes.MD5 = '79054025255fb1a26e4bc422aef54eb4'] FOLLOWEDBY [windows-registry-key:key = 'HKEY_LOCAL_MACHINE\\\\foo\\\\bar']) WITHIN 300 SECONDS" # noqa
def test_create_comparison_expression():
exp = stix2.EqualityComparisonExpression(
"file:hashes.'SHA-256'",
stix2.HashConstant("aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f", "SHA-256"),
) # noqa
assert str(exp) == "file:hashes.'SHA-256' = 'aec070645fe53ee3b3763059376134f058cc337247c978add178b6ccdfb0019f'"
def test_list2():
# alternate way to construct an "IN" Comparison Expression
exp = stix2.EqualityComparisonExpression(
"process:name",
['proccy', 'proximus', 'badproc'],
)
assert str(exp) == "process:name IN ('proccy', 'proximus', 'badproc')"
def test_invalid_constant_type():
with pytest.raises(ValueError) as excinfo:
stix2.EqualityComparisonExpression(
"artifact:payload_bin",
{'foo': 'bar'},
)
assert 'Unable to create a constant' in str(excinfo)
def test_binary():
const = stix2.BinaryConstant("dGhpcyBpcyBhIHRlc3Q=")
exp = stix2.EqualityComparisonExpression(
"artifact:payload_bin",
const,
)
assert str(exp) == "artifact:payload_bin = b'dGhpcyBpcyBhIHRlc3Q='"
def test_artifact_payload():
exp1 = stix2.EqualityComparisonExpression("artifact:mime_type",
"application/vnd.tcpdump.pcap")
exp2 = stix2.MatchesComparisonExpression("artifact:payload_bin",
stix2.StringConstant("\\xd4\\xc3\\xb2\\xa1\\x02\\x00\\x04\\x00"))
and_exp = stix2.AndBooleanExpression([exp1, exp2])
exp = stix2.ObservationExpression(and_exp)
assert str(exp) == "[artifact:mime_type = 'application/vnd.tcpdump.pcap' AND artifact:payload_bin MATCHES '\\\\xd4\\\\xc3\\\\xb2\\\\xa1\\\\x02\\\\x00\\\\x04\\\\x00']" # noqa
def test_invalid_constant_type():
with pytest.raises(ValueError):
stix2.EqualityComparisonExpression(
"artifact:payload_bin",
{'foo': 'bar'},
)
def test_boolean():
exp = stix2.EqualityComparisonExpression(
"email-message:is_multipart",
True,
)
assert str(exp) == "email-message:is_multipart = true"
def process_reports(self, reports):
if reports is None:
printer.error("No results")
return
for report in reports:
name = report["name"]
id = report["id"]
stix2_objects = []
stix2_object_refs = []
# FFS AV, consistency!
if 'tlp' in report:
tlp_id = REF_TLPS[report['tlp'].upper()]
elif 'TLP' in report:
tlp_id = REF_TLPS[report['TLP'].upper()]
else:
tlp_id = REF_TLPS['WHITE']
sectors = report['industries']
if sectors:
unmatched_sectors = []
added_sector = False
for sector in [html.unescape(x.upper()) for x in sectors]:
sector_name = None
sector_id = None
if sector in SECTOR_MAPPINGS:
# sector_ids.append(self.octi_sectors[SECTOR_MAPPINGS[sector]])
sector_name = SECTOR_MAPPINGS[sector]
try:
sector_id = self.octi_sectors[
SECTOR_MAPPINGS[sector]]
except Exception as e:
printer.error(e)
continue
else:
printer.debug(f"Looking for sector {sector}")
match = difflib.get_close_matches(
sector, self.octi_sectors.keys(), 1)
if not len(match):
printer.error(
f"Unable to determine a matching sector for {sector}"
)
unmatched_sectors.append(sector)
continue
# sector_ids.append(self.octi_sectors[match[0]])
sector_name = match[0]
sector_id = self.octi_sectors[match[0]]
if sector_name is not None:
s = stix2.Identity(id=sector_id,
name=sector_name,
identity_class='class',
custom_properties={
'x_opencti_identity_type':
'sector'
})
printer.debug(f"Adding sector {sector_name}")
stix2_objects.append(s)
stix2_object_refs.append(s)
added_sector = True
if not added_sector:
printer.warn("Adding 'UNKNOWN' placeholder sector")
s = stix2.Identity(id=self.octi_sectors["UNKNOWN"],
name="Unknown",
identity_class='class',
custom_properties={
'x_opencti_identity_type': 'sector'
})
stix2_objects.append(s)
stix2_object_refs.append(s)
description = report['description']
if len(unmatched_sectors):
description = description + "\n\n###\nUnable to find a match for the following sectors, " \
"please review manually:\n - " + '\n - '.join(unmatched_sectors)
printer.info(f"Generating STIX2 for {name} ({id})")
author = stix2.Identity(name=report['author_name'],
identity_class='organization')
stix2_objects.append(author)
adversary = None
if report['adversary']:
printer.debug("Adding adversary {}".format(
report['adversary']))
adversary = stix2.IntrusionSet(name=report['adversary'])
stix2_object_refs.append(adversary)
stix2_objects.append(adversary)
if report['targeted_countries']:
for country in report['targeted_countries']:
printer.debug(f"Adding country {country}")
c = stix2.Identity(name=country,
identity_class='organization',
custom_properties={
'x_opencti_identity_type':
'country'
})
stix2_objects.append(c)
stix2_object_refs.append(c)
external_refs = []
for eref in report['references']:
external_refs.append(
stix2.ExternalReference(source_name=tldextract.extract(
eref).registered_domain,
url=eref))
indicators = report["indicators"]
if indicators:
for indicator in indicators:
resolved_type = self.resolve_type(
indicator["type"].lower())
if resolved_type != None and indicator["is_active"]:
observable_type = resolved_type
observable_value = indicator["indicator"]
pattern_type = 'stix'
try:
if observable_type in PATTERNTYPES:
pattern_type = observable_type
elif observable_type not in OPENCTISTIX2:
printer.info("Not in stix2 dict")
else:
if 'transform' in OPENCTISTIX2[
observable_type]:
if OPENCTISTIX2[observable_type][
'transform'][
'operation'] == 'remove_string':
observable_value = observable_value.replace(
OPENCTISTIX2[observable_type]
['transform']['value'], '')
lhs = stix2.ObjectPath(
OPENCTISTIX2[observable_type]['type'],
OPENCTISTIX2[observable_type]['path'])
observable_value = stix2.ObservationExpression(
stix2.EqualityComparisonExpression(
lhs, observable_value))
except Exception as e:
printer.error(e)
printer.info(
"Could not determine suitable pattern")
try:
indicator_obj = stix2.Indicator(
name=indicator["indicator"],
description=indicator["description"],
pattern=str(observable_value),
valid_from=indicator["created"],
labels=['malicious-activity'],
created_by_ref=author,
object_marking_refs=[tlp_id],
custom_properties={
'x_opencti_observable_type':
resolved_type,
'x_opencti_observable_value':
indicator["indicator"],
'x_opencti_pattern_type':
pattern_type
})
stix2_object_refs.append(indicator_obj)
stix2_objects.append(indicator_obj)
except Exception as e:
printer.error(e)
printer.info("Couldn't fetch indicator")
else:
printer.error("No indicators")
report = stix2.Report(name=name,
description=description,
created_by_ref=author,
labels=['threat-report'],
published=report['created'],
created=report['created'],
modified=report['modified'],
object_refs=stix2_object_refs,
object_marking_refs=[tlp_id],
external_references=external_refs)
stix2_objects.append(report)
bundle = stix2.Bundle(stix2_objects).serialize()
if not self.dryrun:
self.opencti_connector_helper.send_stix2_bundle(
bundle, None, True, False)
printer.info("Sending to OpenCTI")
#printer.debug(str(bundle))
else:
printer.debug(f"No sectors, disregarding '{name}'")
