diff --git a/stix2/properties.py b/stix2/properties.py
index ca7f04c..41841b6 100644
--- a/stix2/properties.py
+++ b/stix2/properties.py
@@ -129,6 +129,8 @@ class ListProperty(Property):
                 # constructor again
                 result.append(valid)
                 continue
+            elif type(self.contained) is DictionaryProperty:
+                obj_type = dict
             else:
                 obj_type = self.contained
 
diff --git a/stix2/utils.py b/stix2/utils.py
index 9febd78..4ef3d23 100644
--- a/stix2/utils.py
+++ b/stix2/utils.py
@@ -166,7 +166,7 @@ def get_dict(data):
 def find_property_index(obj, properties, tuple_to_find):
     """Recursively find the property in the object model, return the index
     according to the _properties OrderedDict. If it's a list look for
-    individual objects.
+    individual objects. Returns and integer indicating its location
     """
     from .base import _STIXBase
     try:
@@ -183,6 +183,11 @@ def find_property_index(obj, properties, tuple_to_find):
                                                   tuple_to_find)
                         if val is not None:
                             return val
+                    elif isinstance(item, dict):
+                        for idx, val in enumerate(sorted(item)):
+                            if (tuple_to_find[0] == val and
+                                    item.get(val) == tuple_to_find[1]):
+                                return idx
             elif isinstance(pv, dict):
                 if pv.get(tuple_to_find[0]) is not None:
                     try:

Create an Extension with Dict annidate inside List
Hi,
I'm trying to create a CyberObservable Extension for UserAccount which have to contain a DictionaryProperty() inside a ListProperty(). It is possible? Because when I try to create an extension like this one

```
@CustomExtension(UserAccount, 'ssh_keys', {
   keys': ListProperty(DictionaryProperty(), required=True)
 })
 class SSHKeysExtension:
     pass
```

and use it with example = SSHKeysExtension(keys=[{'test123':123, 'test345','aaaa'}])
I obtain a lot of strange errors (the library seems to interpreter the dict as parameters for __init__()

diff --git a/stix2/test/test_custom.py b/stix2/test/test_custom.py
index a14503f..b45670f 100644
--- a/stix2/test/test_custom.py
+++ b/stix2/test/test_custom.py
@@ -479,6 +479,27 @@ def test_custom_extension_wrong_observable_type():
     assert 'Cannot determine extension type' in excinfo.value.reason
 
 
+@pytest.mark.parametrize("data", [
+    """{
+    "keys": [
+        {
+            "test123": 123,
+            "test345": "aaaa"
+        }
+    ]
+}""",
+])
+def test_custom_extension_with_list_and_dict_properties_observable_type(data):
+    @stix2.observables.CustomExtension(stix2.UserAccount, 'some-extension', [
+        ('keys', stix2.properties.ListProperty(stix2.properties.DictionaryProperty, required=True))
+    ])
+    class SomeCustomExtension:
+        pass
+
+    example = SomeCustomExtension(keys=[{'test123': 123, 'test345': 'aaaa'}])
+    assert data == str(example)
+
+
 def test_custom_extension_invalid_observable():
     # These extensions are being applied to improperly-created Observables.
     # The Observable classes should have been created with the CustomObservable decorator.
diff --git a/stix2/test/test_properties.py b/stix2/test/test_properties.py
index 34edc96..16ff06a 100644
--- a/stix2/test/test_properties.py
+++ b/stix2/test/test_properties.py
@@ -1,6 +1,6 @@
 import pytest
 
-from stix2 import EmailMIMEComponent, ExtensionsProperty, TCPExt
+from stix2 import CustomObject, EmailMIMEComponent, ExtensionsProperty, TCPExt
 from stix2.exceptions import AtLeastOnePropertyError, DictionaryKeyError
 from stix2.properties import (BinaryProperty, BooleanProperty,
                               DictionaryProperty, EmbeddedObjectProperty,
@@ -266,6 +266,17 @@ def test_dictionary_property_invalid(d):
     assert str(excinfo.value) == d[1]
 
 
+def test_property_list_of_dictionary():
+    @CustomObject('x-new-obj', [
+        ('property1', ListProperty(DictionaryProperty(), required=True)),
+    ])
+    class NewObj():
+        pass
+
+    test_obj = NewObj(property1=[{'foo': 'bar'}])
+    assert test_obj.property1[0]['foo'] == 'bar'
+
+
 @pytest.mark.parametrize("value", [
     {"sha256": "6db12788c37247f2316052e142f42f4b259d6561751e5f401a1ae2a6df9c674b"},
     [('MD5', '2dfb1bcc980200c6706feee399d41b3f'), ('RIPEMD-160', 'b3a8cd8a27c90af79b3c81754f267780f443dfef')],

pip install -e .[taxii]
parse_log_pytest
requirements.txt
pytest pytest-cov
3.6
requirements.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
alabaster==0.7.13
antlr4-python3-runtime==4.9.3
async-generator==1.10
attrs==22.2.0
Babel==2.11.0
backcall==0.2.0
bleach==4.1.0
bump2version==1.0.1
bumpversion==0.6.0
certifi==2021.5.30
cfgv==3.3.1
charset-normalizer==2.0.12
coverage==6.2
decorator==5.1.1
defusedxml==0.7.1
distlib==0.3.9
docutils==0.18.1
entrypoints==0.4
filelock==3.4.1
identify==2.4.4
idna==3.10
imagesize==1.4.1
importlib-metadata==4.8.3
importlib-resources==5.2.3
iniconfig==1.1.1
ipython==7.16.3
ipython-genutils==0.2.0
jedi==0.17.2
Jinja2==3.0.3
jsonschema==3.2.0
jupyter-client==7.1.2
jupyter-core==4.9.2
jupyterlab-pygments==0.1.2
MarkupSafe==2.0.1
mistune==0.8.4
nbclient==0.5.9
nbconvert==6.0.7
nbformat==5.1.3
nbsphinx==0.3.2
nest-asyncio==1.6.0
nodeenv==1.6.0
packaging==21.3
pandocfilters==1.5.1
parso==0.7.1
pexpect==4.9.0
pickleshare==0.7.5
platformdirs==2.4.0
pluggy==1.0.0
pre-commit==2.17.0
prompt-toolkit==3.0.36
ptyprocess==0.7.0
py==1.11.0
Pygments==2.14.0
pyparsing==3.1.4
pyrsistent==0.18.0
pytest==7.0.1
pytest-cov==4.0.0
python-dateutil==2.9.0.post0
pytz==2025.2
PyYAML==6.0.1
pyzmq==25.1.2
requests==2.27.1
simplejson==3.20.1
six==1.17.0
snowballstemmer==2.2.0
Sphinx==1.5.6
sphinx-prompt==1.5.0
-e git+https://github.com/oasis-open/cti-python-stix2.git@2d689815d743611a8f3ccd48ce5e2d1ec70695e5#egg=stix2
stix2-patterns==2.0.0
taxii2-client==2.3.0
testpath==0.6.0
toml==0.10.2
tomli==1.2.3
tornado==6.1
tox==3.28.0
traitlets==4.3.3
typing_extensions==4.1.1
urllib3==1.26.20
virtualenv==20.16.2
wcwidth==0.2.13
webencodings==0.5.1
zipp==3.6.0

name: cti-python-stix2
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - alabaster==0.7.13
      - antlr4-python3-runtime==4.9.3
      - async-generator==1.10
      - attrs==22.2.0
      - babel==2.11.0
      - backcall==0.2.0
      - bleach==4.1.0
      - bump2version==1.0.1
      - bumpversion==0.6.0
      - cfgv==3.3.1
      - charset-normalizer==2.0.12
      - coverage==6.2
      - decorator==5.1.1
      - defusedxml==0.7.1
      - distlib==0.3.9
      - docutils==0.18.1
      - entrypoints==0.4
      - filelock==3.4.1
      - identify==2.4.4
      - idna==3.10
      - imagesize==1.4.1
      - importlib-metadata==4.8.3
      - importlib-resources==5.2.3
      - iniconfig==1.1.1
      - ipython==7.16.3
      - ipython-genutils==0.2.0
      - jedi==0.17.2
      - jinja2==3.0.3
      - jsonschema==3.2.0
      - jupyter-client==7.1.2
      - jupyter-core==4.9.2
      - jupyterlab-pygments==0.1.2
      - markupsafe==2.0.1
      - mistune==0.8.4
      - nbclient==0.5.9
      - nbconvert==6.0.7
      - nbformat==5.1.3
      - nbsphinx==0.3.2
      - nest-asyncio==1.6.0
      - nodeenv==1.6.0
      - packaging==21.3
      - pandocfilters==1.5.1
      - parso==0.7.1
      - pexpect==4.9.0
      - pickleshare==0.7.5
      - platformdirs==2.4.0
      - pluggy==1.0.0
      - pre-commit==2.17.0
      - prompt-toolkit==3.0.36
      - ptyprocess==0.7.0
      - py==1.11.0
      - pygments==2.14.0
      - pyparsing==3.1.4
      - pyrsistent==0.18.0
      - pytest==7.0.1
      - pytest-cov==4.0.0
      - python-dateutil==2.9.0.post0
      - pytz==2025.2
      - pyyaml==6.0.1
      - pyzmq==25.1.2
      - requests==2.27.1
      - simplejson==3.20.1
      - six==1.17.0
      - snowballstemmer==2.2.0
      - sphinx==1.5.6
      - sphinx-prompt==1.5.0
      - stix2-patterns==2.0.0
      - taxii2-client==2.3.0
      - testpath==0.6.0
      - toml==0.10.2
      - tomli==1.2.3
      - tornado==6.1
      - tox==3.28.0
      - traitlets==4.3.3
      - typing-extensions==4.1.1
      - urllib3==1.26.20
      - virtualenv==20.16.2
      - wcwidth==0.2.13
      - webencodings==0.5.1
      - zipp==3.6.0
prefix: /opt/conda/envs/cti-python-stix2

stix2/test/test_custom.py::test_custom_extension_with_list_and_dict_properties_observable_type[{\n stix2/test/test_properties.py::test_property_list_of_dictionary
stix2/test/test_custom.py::test_identity_custom_property stix2/test/test_custom.py::test_identity_custom_property_invalid stix2/test/test_custom.py::test_identity_custom_property_allowed stix2/test/test_custom.py::test_parse_identity_custom_property[{\n stix2/test/test_custom.py::test_custom_property_in_bundled_object stix2/test/test_custom.py::test_identity_custom_property_revoke stix2/test/test_custom.py::test_identity_custom_property_edit_markings stix2/test/test_custom.py::test_custom_marking_no_init_1 stix2/test/test_custom.py::test_custom_marking_no_init_2 stix2/test/test_custom.py::test_custom_object_raises_exception stix2/test/test_custom.py::test_custom_object_type stix2/test/test_custom.py::test_custom_object_no_init_1 stix2/test/test_custom.py::test_custom_object_no_init_2 stix2/test/test_custom.py::test_parse_custom_object_type stix2/test/test_custom.py::test_parse_unregistered_custom_object_type stix2/test/test_custom.py::test_parse_unregistered_custom_object_type_w_allow_custom stix2/test/test_custom.py::test_custom_observable_object_1 stix2/test/test_custom.py::test_custom_observable_object_2 stix2/test/test_custom.py::test_custom_observable_object_3 stix2/test/test_custom.py::test_custom_observable_raises_exception stix2/test/test_custom.py::test_custom_observable_object_no_init_1 stix2/test/test_custom.py::test_custom_observable_object_no_init_2 stix2/test/test_custom.py::test_custom_observable_object_invalid_ref_property stix2/test/test_custom.py::test_custom_observable_object_invalid_refs_property stix2/test/test_custom.py::test_custom_observable_object_invalid_refs_list_property stix2/test/test_custom.py::test_custom_observable_object_invalid_valid_refs stix2/test/test_custom.py::test_custom_no_properties_raises_exception stix2/test/test_custom.py::test_custom_wrong_properties_arg_raises_exception stix2/test/test_custom.py::test_parse_custom_observable_object stix2/test/test_custom.py::test_parse_unregistered_custom_observable_object stix2/test/test_custom.py::test_parse_invalid_custom_observable_object stix2/test/test_custom.py::test_observable_custom_property stix2/test/test_custom.py::test_observable_custom_property_invalid stix2/test/test_custom.py::test_observable_custom_property_allowed stix2/test/test_custom.py::test_observed_data_with_custom_observable_object stix2/test/test_custom.py::test_custom_extension_raises_exception stix2/test/test_custom.py::test_custom_extension stix2/test/test_custom.py::test_custom_extension_wrong_observable_type stix2/test/test_custom.py::test_custom_extension_invalid_observable stix2/test/test_custom.py::test_custom_extension_no_properties stix2/test/test_custom.py::test_custom_extension_empty_properties stix2/test/test_custom.py::test_custom_extension_dict_properties stix2/test/test_custom.py::test_custom_extension_no_init_1 stix2/test/test_custom.py::test_custom_extension_no_init_2 stix2/test/test_custom.py::test_parse_observable_with_custom_extension stix2/test/test_custom.py::test_parse_observable_with_unregistered_custom_extension stix2/test/test_custom.py::test_register_custom_object stix2/test/test_custom.py::test_extension_property_location stix2/test/test_properties.py::test_property stix2/test/test_properties.py::test_basic_clean stix2/test/test_properties.py::test_property_default stix2/test/test_properties.py::test_fixed_property stix2/test/test_properties.py::test_list_property stix2/test/test_properties.py::test_string_property stix2/test/test_properties.py::test_type_property stix2/test/test_properties.py::test_id_property stix2/test/test_properties.py::test_integer_property_valid[2] stix2/test/test_properties.py::test_integer_property_valid[-1] stix2/test/test_properties.py::test_integer_property_valid[3.14] stix2/test/test_properties.py::test_integer_property_valid[False] stix2/test/test_properties.py::test_integer_property_invalid[something] stix2/test/test_properties.py::test_integer_property_invalid[value1] stix2/test/test_properties.py::test_float_property_valid[2] stix2/test/test_properties.py::test_float_property_valid[-1] stix2/test/test_properties.py::test_float_property_valid[3.14] stix2/test/test_properties.py::test_float_property_valid[False] stix2/test/test_properties.py::test_float_property_invalid[something] stix2/test/test_properties.py::test_float_property_invalid[value1] stix2/test/test_properties.py::test_boolean_property_valid[True0] stix2/test/test_properties.py::test_boolean_property_valid[False0] stix2/test/test_properties.py::test_boolean_property_valid[True1] stix2/test/test_properties.py::test_boolean_property_valid[False1] stix2/test/test_properties.py::test_boolean_property_valid[true] stix2/test/test_properties.py::test_boolean_property_valid[false] stix2/test/test_properties.py::test_boolean_property_valid[TRUE] stix2/test/test_properties.py::test_boolean_property_valid[FALSE] stix2/test/test_properties.py::test_boolean_property_valid[T] stix2/test/test_properties.py::test_boolean_property_valid[F] stix2/test/test_properties.py::test_boolean_property_valid[t] stix2/test/test_properties.py::test_boolean_property_valid[f] stix2/test/test_properties.py::test_boolean_property_valid[1] stix2/test/test_properties.py::test_boolean_property_valid[0] stix2/test/test_properties.py::test_boolean_property_invalid[abc] stix2/test/test_properties.py::test_boolean_property_invalid[value1] stix2/test/test_properties.py::test_boolean_property_invalid[value2] stix2/test/test_properties.py::test_boolean_property_invalid[2] stix2/test/test_properties.py::test_boolean_property_invalid[-1] stix2/test/test_properties.py::test_reference_property stix2/test/test_properties.py::test_timestamp_property_valid[2017-01-01T12:34:56Z] stix2/test/test_properties.py::test_timestamp_property_valid[2017-01-01 stix2/test/test_properties.py::test_timestamp_property_valid[Jan stix2/test/test_properties.py::test_timestamp_property_invalid stix2/test/test_properties.py::test_binary_property stix2/test/test_properties.py::test_hex_property stix2/test/test_properties.py::test_dictionary_property_valid[d0] stix2/test/test_properties.py::test_dictionary_property_valid[d1] stix2/test/test_properties.py::test_dictionary_property_invalid_key[d0] stix2/test/test_properties.py::test_dictionary_property_invalid_key[d1] stix2/test/test_properties.py::test_dictionary_property_invalid_key[d2] stix2/test/test_properties.py::test_dictionary_property_invalid[d0] stix2/test/test_properties.py::test_dictionary_property_invalid[d1] stix2/test/test_properties.py::test_hashes_property_valid[value0] stix2/test/test_properties.py::test_hashes_property_valid[value1] stix2/test/test_properties.py::test_hashes_property_invalid[value0] stix2/test/test_properties.py::test_hashes_property_invalid[value1] stix2/test/test_properties.py::test_embedded_property stix2/test/test_properties.py::test_enum_property_valid[value0] stix2/test/test_properties.py::test_enum_property_valid[value1] stix2/test/test_properties.py::test_enum_property_valid[b] stix2/test/test_properties.py::test_enum_property_invalid stix2/test/test_properties.py::test_extension_property_valid stix2/test/test_properties.py::test_extension_property_invalid[1] stix2/test/test_properties.py::test_extension_property_invalid[data1] stix2/test/test_properties.py::test_extension_property_invalid_type stix2/test/test_properties.py::test_extension_at_least_one_property_constraint
stix2/properties.py stix2/utils.py
stix2/properties.py stix2/utils.py