chg: [app] Improved data selection, condition checking and evaluation definition

exercise.py

@@ -134,9 +134,10 @@ def get_model_action(data: dict):
 def is_accepted_query(data: dict) -> bool:
     model, action = get_model_action(data)
     if model in ['Event', 'Attribute', 'Object', 'Tag',]:
-        if action in ['add', 'edit', 'delete',]:
+        if action in ['add', 'edit', 'delete', 'publish']:
-            if data['Log']['change'].startswith('attribute_count'):
+            # # improved condition below. It blocks some queries
-                return False
+            # if data['Log']['change'].startswith('attribute_count'):
+            #     return False
             if data['Log']['change'].startswith('Validation errors:'):
                 return False
             return True
@@ -218,7 +219,7 @@ def check_inject(user_id: int, inject: dict, data: dict, context: dict) -> bool:
 
 
 def is_valid_evaluation_context(user_id: int, inject_evaluation: dict, data: dict, context: dict) -> bool:
-    if 'evaluation_context' not in inject_evaluation:
+    if 'evaluation_context' not in inject_evaluation or len(inject_evaluation['evaluation_context']) == 0:
         return True
     if 'request_is_rest' in inject_evaluation['evaluation_context']:
         if 'request_is_rest' in context:
@@ -266,14 +267,21 @@ def get_data_to_validate(user_id: int, inject_evaluation: dict, data: dict) -> U
 
 def parse_event_id_from_log(data: dict) -> Union[int, None]:
     event_id_from_change_field_regex = r".*event_id \(.*\) => \((\d+)\).*"
+    event_id_from_title_field_regex = r".*from Event \((\d+)\).*"
     if 'Log' in data:
         log = data['Log']
+        if 'model' in log and 'model_id' in log and log['model'] == 'Event':
+            return int(log['model_id'])
         if 'change' in log:
             event_id_search = re.search(event_id_from_change_field_regex, log['change'], re.IGNORECASE)
-            if event_id_search is None:
+            if event_id_search is not None:
-                return None
+                event_id = event_id_search.group(1)
-            event_id = event_id_search.group(1)
+                return event_id
-            return event_id
+        if 'title' in log:
+            event_id_search = re.search(event_id_from_title_field_regex, log['title'], re.IGNORECASE)
+            if event_id_search is not None:
+                event_id = event_id_search.group(1)
+                return event_id
     return None
 
 

exercises/ransomware-exercise.json

@@ -236,12 +236,11 @@
               }
             },
             {
-              ".Event.Object[].Attribute": {
+              ".Event.Object[].Attribute[] | select(.object_relation == \"email-body\")": {
-                "comparison": "contains",
+                "extract_type": "all",
+                "comparison": "count",
                 "values": [
-                  {
+                  ">=1"
-                    "type": "email-body"
-                  }
                 ]
               }
             }
@@ -274,16 +273,11 @@
               }
             },
             {
-              ".Event.Object[].Attribute": {
+              ".Event.Object[].Attribute[] | select((.type == \"filename\")).value": {
-                "comparison": "contains",
+                "extract_type": "all",
+                "comparison": "equals",
                 "values": [
-                  {
+                  "cryptolocker.exe"
-                    "type": "malware-sample"
-                  },
-                  {
-                    "type": "filename",
-                    "value": "cryptolocker.exe"
-                  }
                 ]
               }
             }
@@ -316,12 +310,11 @@
               }
             },
             {
-              ".Event.Object[] | select((.name == \"domain-ip\") or (.name == \"ip-port\"))": {
+              ".Event.Object[] | select((.name == \"domain-ip\") or (.name == \"ip-port\")) | .Attribute[].value": {
+                "extract_type": "all",
                 "comparison": "contains",
                 "values": [
-                  {
+                  "81.177.170.166"
-                    "value": "81.177.170.166"
-                  }
                 ]
               }
             }
@@ -354,12 +347,11 @@
               }
             },
             {
-              "[.Event.Object[], .Event.Attribute[]]": {
+              "[.Event.Object[].Attribute[], .Event.Attribute[]] | .[].value": {
-                "comparison": "contains",
+                "extract_type": "all",
+                "comparison": "contains-regex",
                 "values": [
-                  {
+                    "HKCU.+SOFTWARE.+CryptoLocker.*"
-                    "value": "HKCU\\SOFTWARE\\CryptoLocker VersionInfo"
-                  }
                 ]
               }
             }
@@ -392,12 +384,11 @@
               }
             },
             {
-              ".Event.Object[]": {
+              "[.Event.Object[].Attribute[], .Event.Attribute[]] | .[].value": {
-                "comparison": "contains",
+                "extract_type": "all",
+                "comparison": "contains-regex",
                 "values": [
-                  {
+                    "-----BEGIN PUBLIC KEY-----.*"
-                    "object_relation": "Public"
-                  }
                 ]
               }
             }
@@ -430,7 +421,8 @@
               }
             },
             {
-              ".Event.Tag[].name": {
+              ".Event.Tag | select(length > 0) | .[].name": {
+                "extract_type": "all",
                 "comparison": "count",
                 "values": [
                   ">=3"

inject_evaluator.py

@@ -6,8 +6,12 @@ import operator
 
 
 # .Event.Attribute[] | select(.value == "evil.exe") | .Tag
-def jq_extract(path: str, data: dict):
+def jq_extract(path: str, data: dict, extract_type='first'):
-    return jq.compile(path).input_value(data).first()
+    query = jq.compile(path).input_value(data)
+    try:
+        return query.first() if extract_type == 'first' else query.all()
+    except StopIteration:
+        return None
 
 
 ##
@@ -15,6 +19,8 @@ def jq_extract(path: str, data: dict):
 ##
 
 def condition_satisfied(evaluation_config: dict, data_to_validate: Union[dict, list, str]) -> bool:
+    if type(data_to_validate) is bool:
+        data_to_validate = "1" if data_to_validate else "0"
     if type(data_to_validate) is str:
         return eval_condition_str(evaluation_config, data_to_validate)
     elif type(data_to_validate) is list:
@@ -61,15 +67,54 @@ def eval_condition_list(evaluation_config: dict, data_to_validate: str) -> bool:
     if len(values) == 0:
         return False
 
-    data_to_validate_set = set(data_to_validate)
-    values_set = set(values)
 
+    if comparison_type == 'contains' or comparison_type == 'equals':
+        data_to_validate_set = set(data_to_validate)
+        values_set = set(values)
+        intersection = data_to_validate_set & values_set
+        if comparison_type == 'contains':
+            return len(intersection) == len(values_set)
+        elif comparison_type == 'equals':
+            return len(intersection) == len(values_set) and len(intersection) == len(data_to_validate_set)
+    if comparison_type == 'contains-regex':
+        regex = re.compile(values[0])
+        for candidate in data_to_validate:
+            if regex.match(candidate):
+                return True
+        return False
+    elif comparison_type == 'count':
+        value = values[0]
+        if value.isdigit():
+            return len(data_to_validate) == value
+        elif value[:2] in comparators.keys():
+            count = len(data_to_validate)
+            value_operator = values[0][:2]
+            value = int(value[2:])
+            return comparators[value_operator](count, value)
+        elif value[0] in comparators.keys():
+            count = len(data_to_validate)
+            value_operator = value[0]
+            value = int(value[1:])
+            return comparators[value_operator](count, value)
+    return False
+
+
+def eval_condition_dict(evaluation_config: dict, data_to_validate: str) -> bool:
+    comparison_type = evaluation_config['comparison']
+    values = evaluation_config['values']
+    comparators = {
+        '<': operator.lt,
+        '<=': operator.le,
+        '>': operator.gt,
+        '>=': operator.ge,
+        '=': operator.eq,
+    }
+
+    comparison_type = evaluation_config['comparison']
     if comparison_type == 'contains':
-        intersection = data_to_validate_set & values_set
+        pass
-        return len(intersection) == len(values_set)
     elif comparison_type == 'equals':
-        intersection = data_to_validate_set & values_set
+        pass
-        return len(intersection) == len(values_set) and len(intersection) == len(data_to_validate_set)
     elif comparison_type == 'count':
         if values[0].isdigit():
             return len(data_to_validate) == values[0]
@@ -81,23 +126,12 @@ def eval_condition_list(evaluation_config: dict, data_to_validate: str) -> bool:
     return False
 
 
-def eval_condition_dict(evaluation_config: dict, data_to_validate: str) -> bool:
-    print('Condition on dict not supported yet')
-    comparison_type = evaluation_config['comparison']
-    if comparison_type == 'contains':
-        pass
-    elif comparison_type == 'equals':
-        pass
-    elif comparison_type == 'count':
-        pass
-    return False
-
-
 def eval_data_filtering(user_id: int, inject_evaluation: dict, data: dict) -> bool:
     for evaluation_params in inject_evaluation['parameters']:
         for evaluation_path, evaluation_config in evaluation_params.items():
-            data_to_validate = jq_extract(evaluation_path, data)
+            data_to_validate = jq_extract(evaluation_path, data, evaluation_config.get('extract_type', 'first'))
             if data_to_validate is None:
+                print('Could not extract data')
                 return False
             if not condition_satisfied(evaluation_config, data_to_validate):
                 return False

misp_api.py

@@ -20,7 +20,7 @@ def get(url, data={}, api_key=misp_apikey):
     }
     full_url = urljoin(misp_url, url)
     response = requests.get(full_url, data=data, headers=headers, verify=not misp_skipssl)
-    return response.json() if response.headers['content-type'] == 'application/json' else response.text
+    return response.json() if response.headers['content-type'].startswith('application/json') else response.text
 
 
 def post(url, data={}, api_key=misp_apikey):
@@ -32,7 +32,7 @@ def post(url, data={}, api_key=misp_apikey):
     }
     full_url = urljoin(misp_url, url)
     response = requests.post(full_url, data=json.dumps(data), headers=headers, verify=not misp_skipssl)
-    return response.json() if response.headers['content-type'] == 'application/json' else response.text
+    return response.json() if response.headers['content-type'].startswith('application/json') else response.text
 
 
 def getEvent(event_id: int) -> Union[None, dict]:

notification.py

@@ -101,7 +101,7 @@ def get_notification_message(data: dict) -> dict:
     response_code = data.get('response_code', '?')
     user_agent = data.get('user_agent', '?')
     _, action = get_scope_action_from_url(url)
-    http_method = 'DELETE' if http_method == 'POST' and action == 'delete' else http_method  # small override for UI
+    http_method = 'DELETE' if (http_method == 'POST' or http_method == 'PUT') and action == 'delete' else http_method  # small override for UI
     payload = get_request_post_body(data)
     return {
         'user': user,
@@ -115,13 +115,18 @@ def get_notification_message(data: dict) -> dict:
     }
 
 
-def get_scope_action_from_url(url) -> str:
+def get_scope_action_from_url(url) -> Union[str, None]:
     split = url.split('/')
-    return (split[1], split[2],)
+    if len(split) > 2:
+        return (split[1], split[2],)
+    else:
+        return (None, None,)
 
 
 def is_accepted_notification(notification) -> bool:
-    if notification['user_agent'] == 'misp-exercise-dashboard':
+    if notification['user_agent'] == 'misp-exercise-dashboard': # Ignore message generated from this app
+        return False
+    if '@' not in notification['user']: # Ignore message from system
         return False
 
     scope, action = get_scope_action_from_url(notification['url'])

server.py

@@ -65,7 +65,7 @@ def handleMessage(topic, s, message):
 
     if topic == 'misp_json_audit':
         user_id, email = notification_model.get_user_email_id_pair(data)
-        if user_id is not None:
+        if user_id is not None and '@' in email:
             if user_id not in db.USER_ID_TO_EMAIL_MAPPING:
                 db.USER_ID_TO_EMAIL_MAPPING[user_id] = email
                 sio.emit('new_user', email)
@@ -107,8 +107,10 @@ def forward_zmq_to_socketio():
     while True:
         message = zsocket.recv_string()
         topic, s, m = message.partition(" ")
+        handleMessage(topic, s, m)
         try:
-            handleMessage(topic, s, m)
+            pass
+            # handleMessage(topic, s, m)
         except Exception as e:
             print(e)